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Global Positioning System - Science topic

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First of all, we must concede the "variability" of space-time, and it's a physical reality. First, this is the common ground of both the Special and General Theory of Relativity; the main body of relativity can be trusted to be correct and has been more than adequately verified by experiments. These experiments typically include the earliest light-bending experiments [Eddington 1919], the round-the-world flight experiments [1], the GPS clock-correction experiments [2], and later the LIGO gravitational-wave-detection experiments [3], the observation of gravitational lensing phenomena [4] [5], and so on. The meaning of "variable" is not necessarily the relative spacetime of SR or the curved spacetime of GR. Second, philosophically we should also recognize that spacetime will not be just a variable background for matter, since all interactions cannot be separated from spacetime. Spacetime is not just a distance scale but should take on the function of transmitting interactions.
What our teachers emphasized when they talked about the difference between the applicability of SR and GR is that SR is an event in flat spacetime and GR is an event in curved spacetime. But there is only one spacetime, and for a moving electron, its SR spacetime and GR spacetime would have to be the same** if we had to consider both its SR and GR effects*.
Einstein's fondness for the concept of curved spacetime may have arisen from the intuitive nature of the geodesic concept, or perhaps from the affirmation of the maximal nature of spacetime dynamics. In any case, GR's expression of gravity in terms of a curved spacetime concept was already orthodox, though beyond the empirical perception of all. Feynman constantly questioned the notion of "spacetime curvature" and used the concept of a " measure " of spacetime in general relativity instead of "curvature" [6]. Weinberg thought that geometry might be more appropriately viewed as an analog of GR, politely expressing his skepticism, and L. Susskind, when teaching GR, said that no one knows what four-dimensional spacetime bending looks like†. We believe that Einstein was also not a great believer in the notion of four-dimensional spacetime bending, and his subsequent repeated turn to the study of five-dimensional spacetime[7][8] does not appear to have been solely for the sake of gravitational unification with Maxwell's electromagnetic theory, but perhaps also as a passing attempt to find a dimension for the three-dimensional sphere into which it could be embedded‡.
All of our current measurements and verifications of SR and GR spacetime do not involve true spacetime "curvature", although there are many proposed methods [9]. The LIGO gravitational wave measurements, the gravitational redshift and violetshift, can only be considered as a response to changes in the spacetime metric. This is similar to Feynman's view.
Let us assume a scenario: an electron of mass m in four-dimensional spacetime, and a stationary observer in a fifth-dimensional abstract space, who keeps changing the direction and velocity of the motion of the electron in four-dimensional spacetime through the fifth dimension. Ask, in the opinion of this observer:
1) Do SR spacetime and GR spacetime have to be identical?
2) Is it possible to fully express spacetime "curvature" with a spacetime metric? Excluding " twisting ".
3) Is there a notion of "curvature" for the "curvature" of one-dimensional time? Usually in GR it is also said to be the gravitational time dilation [10]. The curvature of one-dimensional space can have the concept of curvature, but in which direction? How can it not interfere with the other two dimensions?
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Notes:
* Usually physics recognizes that GR effects are ignored because the electron mass is so small. This realization masks great problems. We are extrapolating from macroscopic manifestations to microscopic manifestations, and from manifestations abstracted as point particles at a distance to manifestations when structure exists at close range. As long as structure exists, when distance is sufficiently small, everything behaves as a distributed field. At this point, the abstract notion of force (magnitude, direction, point of action) has disappeared. For electrons, even the concept of charge disappears. Yet the concept of gravity does not necessarily disappear at this point, thus causing a reversal of the order of magnitude difference in action at very close distances.
** There is a difference between this and the state of affairs during GPS clock calibration. When doing GPS calibration, we are using the ground as the reference frame. A flying satellite in the sky has an SR effect, but we approximate it to be flat in space-time. The GR effect, on the other hand, is relative to the ground, not of itself. Thus, the composite calibration is the difference between the two. If one were to change the scenario and the relatively immobile space station if it needed to be calibrated with the clock of some sort of vehicle on the ground moving at high speed around it, then the composite calibration would be the sum of the two. Please correct me if there are problems with this scenario.
† He also said, when teaching QM, that no one knows what the top and bottom spins of the electron are.
‡ Einstein says that the universe is a finite three-dimensional sphere.
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References:
[1] Hafele, J. C. and R. E. Keating (1972). "Around-the-World Atomic Clocks: Observed Relativistic Time Gains." Science 177(4044): 168-170.
[2] "Relativity in GNSS"; Ashtekar, A. and V. Petkov (2014). Springer Handbook of Spacetime. Berlin, Heidelberg, Springer Berlin Heidelberg.
[3] Cahillane, C. and G. Mansell (2022). "Review of the Advanced LIGO gravitational wave observatories leading to observing run four." Galaxies 10(1): 36.
[5] Tran, K.-V. H., A. Harshan, K. Glazebrook, G. K. Vasan, T. Jones, C. Jacobs, G. G. Kacprzak, T. M. Barone, T. E. Collett and A. Gupta (2022). "The AGEL Survey: Spectroscopic Confirmation of Strong Gravitational Lenses in the DES and DECaLS Fields Selected Using Convolutional Neural Networks." The Astronomical Journal 164(4): 148.
[6] Feynman, R. P. (2005). The Feynman Lectures on Physics(II).
[7] Pais, A. (1983). The science and the life of Albert Einstein II Oxford university press.
[8] Weinberg, S. (2005). "Einstein’s Mistakes." Physics Today 58(11).
[9] Ciufolini, I. and M. Demianski (1986). "How to measure the curvature of space-time." Physical Review D 34(4): 1018.
[10] Roura, A. (2022). "Quantum probe of space-time curvature." Science 375(6577): 142-143.
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Discrete symmetries (charge conugation, parity, time reversal, along with the structutaral symmetries of crystals) are a-slightly-different story, since Noether's theorem doesn't apply to them. Their role is different from the symmetries that correspond to continuous transformations-they impose so-called ``selection rules''.
Just some remarks about C and P in the weak interactions: It's a fact-not a belief-that the weak interaction-that describes radioactivity-does not preserve parity: The electrons that are emitted during beta decay all are found to have only one helicity (the projection of their spin along their momentum), not both. That was found experimentally in 1957.
In 1964 it was found that the weak interaction doesn't preserve the combination of charge conjugation and parity: Neutral K-mesons, that ``decay'' through the weak interaction, when prepared in a state of definite charge conjugation AND parity, could be found in a state that was a linear combination thereof.
That the strong interaction (described by quantum chromodynamics)-as does electrodynaamics-preserves the combination of charge conjugation and parity isn't a paradox, however. The coefficient of the interaction that would be responsible for describing the breaking of CP is zero, that's all. And the selection rule implies that fluctuations can't make it contribute.
There's no mystery about the thermal expansion of solids, since the contact with a thermal bath means that the solid is an open system.
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When I try to correlate the gps coordinates among points obtained from field and satellite for the same location there is a big difference among the two. I assume that this is partly due to the satellite image shift. Can anyone tell me how to correlate the two datasets that are actually same but have difference in coordinates?
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I have acquired GPS raw data from the Ublox Neo-6m module. Upon logging the raw data, it came to me as NMEA data. I want to postprocess those data in Matlab. Usually, Rinex observation data is processed, but how do I post-process NMEA data on Matlab without a Rinex file, or is there any procedure to convert those NMEA data to Rinex?
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No, it is not possible to do post-processing using NMEA output only. NMEA is a text-based protocol that is used to transmit GNSS data in real time. It does not contain the raw measurements that are needed for post-processing, such as the pseudoranges and phases.
There are a few approaches to converting NMEA data to a RINEX observation file. One approach is to use a software program that can decode the NMEA data and output it in RINEX format. There are many different software programs available, such as Emlid Studio, Trimble Convert to RINEX, and Topcon TPS2RIN.
Another approach is to use a web-based converter. There are a few different web-based converters available, such as the one provided by the National Geodetic Survey (NGS).
The specific steps involved in converting NMEA data to RINEX format will vary depending on the software or web-based converter that you are using. However, the general steps are as follows:
  1. Select the NMEA data file that you want to convert.
  2. Specify the output format, which should be RINEX.
  3. Choose the options that you want to use for the conversion, such as the type of GNSS data that you want to include and the accuracy of the output file.
  4. Click the "Convert" button.
The converted RINEX file will be saved to your computer. You can then use this file for post-processing or other purposes.
Here are some additional things to keep in mind when converting NMEA data to RINEX format:
  • The NMEA data file must be in a supported format.
  • The software or web-based converter that you are using must be compatible with the NMEA data file format.
  • The output RINEX file will be created in the same directory as the input NMEA data file.
  • The accuracy of the output RINEX file will depend on the quality of the input NMEA data file.
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I need GPS location where noise level data (in dB) is measured for Delhi, Mombai, Kokata, bengaluru in excel/text format.
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What type of noise data you are referring to:
1) Natural Atmospheric noise
2) Manmade or other anthropogenic noise
3) Ambient Earth noise
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Dear researchers,
I am looking for a comprehensive source (e.g. book, article, thesis, etc.) that extensively covers the orbital characteristics of the GPS, GLONASS, Galileo, and BeiDou satellite systems to aid my ongoing study.
Thank you in advance for your suggestions.
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It’s the Kepler elements and the Kepler first law of orbit and the third law of harmonic together with the use of unified global reference frame
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If you have an area of several 25's of acres (several 100,000 m²) and your only source of GNSS Information is that of the drone, can there be distortion of the 3D Model / orthomosaic that are so large that calculations based on this model cannot be trusted?
In other words: Do GCPs not only add global georeferenced accuracy, but also decrease the error of the scale of the result (for example if you want to measure landfill, the surface area or the volume of some rocks or debris) ?
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Yes, without GCPs and RTK/PPK, it is highly possible to obtain wrong or inaccurate geometric information in UAV-based photogrammetric mapping. When dealing with large areas, relying solely on the drone's GNSS information can lead to distortions in the 3D model or orthomosaic. GCPs not only add global georeferenced accuracy but also help decrease errors in the scale of the results, making them essential for reliable measurements.
The accuracy of UAS-based photogrammetric mapping depends on several factors, including Ground Control Points (GCPs), flight height, camera resolution, GNSS accuracy of the device, weather conditions, processing software, user experience, etc. While it is possible to obtain satisfactory 3D models without GCPs or RTK/PPK, for precise measurements such as surface area or volume calculations, GCPs are essential. For more in-depth information, you can refer to my MSc thesis and the following articles. In the following studies, you can find comparisons of processing with and without GCPs as well.
MSc Thesis:
Good luck on your journey of exploration and innovation!
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Could GPS track machine learning?
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Even with the correction, I still haven't made sense of the question.
Regards,
Joachim
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We are currently working on the drones project and looking for GPS datasets for drones under spoofing and jamming attacks.
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1. USAF GPS Spoofing and Jamming Database (GPS-SGJ-2015): This dataset contains 30 hours of global positioning system (GPS) signals collected over the 15-day period in 2015 from a test site at White Sands Missile Range, New Mexico. It includes recorded GPS-L1, GPS-L2C, and GPS-L5 signals, with recognized spoofing and jamming attacks added to the dataset.
2. Runway-UAS Jamming and Spoofing Dataset (RUAS-JS-2015): This dataset contains 60 hours of data collected in 2015 from a test site at White Sands Missile Range, New Mexico. It includes recorded GPS-L1, GPS-L2C, and GPS-L5 signals, with recognized spoofing and jamming attacks added to the dataset.
3. Drone GPS Spoofing and Jamming Dataset (DPJS-2014): This dataset contains 240 hours of data collected in 2014 from a test site at White Sands Missile Range, New Mexico. It includes recorded GPS-L1, GPS-L2C, and GPS-L5 signals, with recognized spoofing and jamming attacks added to the dataset.
4. DARPA UAV GNSS Spoofing Testing Database (GPS-UAV-2014): This dataset contains 300 hours of GNSS (GPS, GLONASS, and Galileo) spoofing detection data collected in 2014 from 3 different UAVs at various test sites in the USA. It includes both true and spoofed GNSS signals, with recognized spoofing and jamming attacks added to the dataset.
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Goodday, Please i need a Literature Review on 'AN INVESTIGATION OF GIS APPLICATION IN LOGISTICS AND SUPPLY CHAIN TRACKING OF CARGO FROM POINT OF ORIGIN TO POINT OF DESTINATION'? i am using a GPS car tracker on the project to demostrate the application.
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Google Scholar is your friend: just put in your keywords, "GIS APPLICATION IN LOGISTICS AND SUPPLY CHAIN TRACKING OF CARGO FROM POINT OF ORIGIN TO POINT OF DESTINATION" and get https://scholar.google.com/scholar?q=GIS+APPLICATION+IN+LOGISTICS+AND+SUPPLY+CHAIN+TRACKING+OF+CARGO+FROM+POINT+OF+ORIGIN+TO+POINT+OF+DESTINATION
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I have some data, which was collected by the fishermen using Garmin GPS. The collected data format is .adm
Please help to convert it in any other format like gpx, csv etc
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Hi! Try this tool from Sourceforge: https://sourceforge.net/projects/gpx-convert-adm/
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Navigation of the ships in the past was impossible without the suitably placed lighthouses on the shore. In modern times we have GPS. My question is whether the lighthouse still plays any role for the sailors or is it nowadays totally irrelevant.
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While GPS has revolutionized navigation for ships, lighthouses still play a significant role in modern navigation. GPS technology is highly reliable, but it can sometimes malfunction due to technical problems or interference, and ships can also face problems with signal reception in certain locations such as harbors or near tall structures. In such situations, lighthouses serve as an important backup navigation aid for sailors.
Moreover, lighthouses can provide additional information for sailors beyond location and navigation. For example, lighthouses can provide information on weather conditions, local hazards, and other important information for sailors. In some cases, lighthouses are also used as landmarks to help identify a ship's position relative to shore.
In addition, many lighthouses have become cultural landmarks and tourist attractions, drawing visitors from around the world. They are often considered historical and cultural icons that provide a glimpse into the maritime history of a region.
Overall, while GPS has largely replaced traditional navigation aids like lighthouses, they still play an important role in modern navigation and are appreciated for their historical and cultural significance.
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We are planning to collar more brown bear and elk for a project I am working on in Alaska. We want hourly fixes via iridium, we also want to include accelerometers on our collars to gather activity data. We have used telonics in the past and have had bad luck with them. I am considering Lotek and Vectronic and would appreciate some advice on other peoples previous experiences.
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Thank you Lars. This is really useful, I appreciate you sharing this.
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We will investigate the relationships between large herbivore movement and biodiversity. For this we need to track Oryx, Eland and Greater Kudu's. I am in contact with some companies (Lotek (UK), GPScollars (UK), African Wildlife Tracking(RSA), Vectronic (GER), Followit (SE)), but still would like to know if you have any recommendations for GPS collars for large herbivores in Southern Africa with irregular GSM-Network.
Thank you very much for sharing your expertise.
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Hi Robert! Great to hear that you are happy with the Vectronic collars. As you are getting acceleromtry you should have a look at https://www.schaeuffelhut-berger.de/wordpress/en/services/products/products-firetail-eng/ It is simply fantastic at getting to actullay see the accelerometer data in connection with the locations. It works best via Movebank.org and you will need to get a special script from them to convert the acc data from the output from Vectronic's own Motion Data Monitor. Let me know if you need further advice.
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Hello everyone,
I am working on cell dosimetry by simulating cell irradiation in biological wells. In the wells, a volume of water in which the cells are constructed independently. Concerning the irradiation source, I want it to just fill the water volume but not the cells, and inversely. By researching, I found the (confine) method using GPS. However I could not apply it appropriately. Can have any help on how to apply it, or any already constructed example that implement this method ? Or even if there are any different methods ?
Thanks in advance for any help.
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I developed a method for generating irregular volume sources. It has been tested and could be used with any volume sources. It might be helpful to you.
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We combine data from different sensors like the Inertial Measurement Unit (IMU) and Global Positioning System (GPS) to estimate the state of a robot e.g. position using Kalman Filter. My question is why do we need to estimate the position if we are getting it from GPS and IMU?
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Raw GPS data only provides 4 measurements of pseudo range. You need an estimator to extract the 3D position measurement and clock bias. The GPS data is then used to estimate the errors in the IMU to provide improved short-term stability for any autopilots (or a navigation capability should the GPS signals be intermittent)
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As far as I know, drones use GPS satellite systems to obtain their position. They usually have associated some degree of error at least you use differential GPS equipment. What other sources do the drone must use to ensure accurate measurement of land surface area?
Regards
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The precision and accuracy are going to be influenced at every stage, from planning through post-processing and cartography. And crudely divided into two categories, internal and external consistency. I recently did an experiment on a friend's property using a consumer grade DJI drone. And I was very fortunate to have a really good lidar dataset and cadastral GIS and property surveys to compare to. The precision and accuracy are not uniform across the data, especially over several flights. In very general terms, having well distributed ground control points had the most influence in the end. Having any sort of DSM is way helpful for flight planning to ensure coverage and inter-visibility of the drone and GCP's. Elevation variance over the flight matters, as well as calibrating the drones altimeter. Vegetation is the greatest interference, and bites during post processing. Overall, I wish the drone operator had far greater understanding of the algorithms and especially the setting of initial parameters before flying. I found that the attitude data of where the camera was point had more influence on the photogrammetry than positional and altitude data.
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I need help in preprocessing RINEX and SCINDA data files from IGS and GPS receiver. Initially I used the Gopi GPS TEC analysis software (versions 3.02 and 3.03), but it has stopped working (it can't download navg. files anymore). If anyone has an alternative or how to work with the current state of Gopi software I would really appreciate.
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1) You can use https://cddis.nasa.gov/archive/gnss/data/daily to download nav and obs RINEX files.
2) I would suggest our TayAbsTEC software at http://www.gnss-lab.org/ . There are two steps 1 - "tec-suite" is to convert RINEX to ASCII files, 2 - "TayAbsTec" is to convert slant TECs to vertical TEC. The software does not need DCBs (it calculates DCBs itself). But you need to download obs and nav files yourself.
3) You can use SIMuRG project (https://simurg.space/) to have TEC, TEC variations or ROTI.
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In some case studies use the GPS location of a nearby village or station when describing study sites, which can be problematic, especially if we want to use information about the site location to extract some data from gridded (mapped) datasets where we need to use the specific location of the experimental plots. For example, the GPS location may indicate urban land whereas the experimental plot lies in forests. Is there any online resource to check the land use type in which a given GPS (longitude, latitude) location lies?
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Well, in case of land changes study, u can use google earth, topography map..
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I am currently working on GNSS Spoofing as my master's thesis and working on GPS signal generation using MATLAB.
I wanted to know whether it is possible to use MATLAB for generating a complete signal of 5 satellites or not?
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Thank you so much for your kind responses. I have completed my Masters thesis and got an A grade on my thesis too. :)
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I’m looking for research testing the accuracy of GPS at various buried depths. I’m wondering if GPS, RTK and LoRa could be used to mark the location of underground utilities.
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@ Thomas, so far I know, 2m is the ideal depth.
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I am doing a forestry research. I need to record the geographical coordinates and altitude values of my experimental plot. Getting a GPS receiver is difficult for me and purchasing a GPS receiver is very expensive. I am thinking of using my smart phone (ios) instead of a GPS receiver. I do not know a very good, technically reliable ios application to get the works done. Please suggest me one ?
Also I need to know whether using a smart phone GPS application is a valid scientific method/scientifically acceptable in scientific researches ?
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Dear Dr. Pete, I have tested forestry before, and found that due to the IOS system can't install open-source positioning applications, it can't achieve high spatial positioning; On the contrary, Android phones can install many open-source positioning software, which can achieve better positioning requirements.
Of course, non professional measurement tools must have a better measurement environment and satellite reception to achieve more satisfactory results.
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I would like to calculate the strain rates from horizontal velocities obtained from data processing of GPS permanent stations .
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Strain Calculator of cronin, 2012. It is both excel and matlab based.
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1) Can the existence of an aether be compatible with local Lorentz invariance?
2) Can classical rigid bodies in translation be studied in this framework?
By taking into account that synchronization of the clocks of inertial frames is a gauge, the answer to 1) and 2) seems to be affirmative. A synchronization can be used that clearly violates global Lorentz symmetry but preserves Lorenzt symmetry in the vecinity of each point of flat spacetime.
Christian Corda showed in 2019 that this effect of clock synchronization is a necessary condition to explain the Mössbauer rotor experiment (Honorable Mention at the Gravity Research Foundation 2018). In fact, it can be easily shown that it is a necessary condition to apply the Lorentz transformation to any experiment involving high velocity particles traveling along two distant points (including the linear Sagnac effect) .
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We may consider the time of a clock placed at an arbitrary coordinate x to be t and the time of a clock placed at an arbitrary coordinate xP to be tP. Let the offset (t – tP) between the two clocks be:
1) (t – tP) = v (x - xP)/c2
where (t-tP) is the so-called Sagnac correction. If we call g to the Lorentz factor for v and we insert 1) into the time-like component of the Lorentz transformation T = g (t - vx/c2) we get:
2) T = g (tP - vxP/c2)
On the other hand, if we assume that the origins coincide x = X = 0 at time tP = 0 we may write down the space-like component of the Lorentz transformation as:
3) X = g(x - vtP)
Assuming that both clocks are placed at the same point x = xP , inserting x =xP , X = XP , T = TP into 2)3) yields:
4) XP = g (xP - vtP)
5) TP = g (tP - vxP/c2)
which is the local Lorentz transformation for an event happening at point P. On the other hand , if the distance between x and xP is different from 0 and xP is placed at the origin of coordinates, we may insert xP = 0 into 2)3) to get:
6) X = g (x - vtP)
7) T = g tP
which is a change of coordinates that it:
- Is compatible with GPS simultaneity.
- Is compatible with the Sagnac effect. This effect can be explained in a very straightfordward manner without the need of using GR or the Langevin coordinates.
- Is compatible with the existence of relativistic extended rigid bodies in translation using the classical definition of rigidity instead of the Born´s definition.
- Can be applied to solve the 2 problems of the preprint below.
- Is compatible with all experimenat corroborations of SR: aberration of light, Ives -Stilwell experiment, Hafele-Keating experiment, ...
Thus, we may conclude that, considering the synchronization condition 1):
a) We get Lorentz invariance at each point of flat space-time (eqs. 4-5) when we use a unique single clock.
b) The Lorentz invariance is broken out when we use two clocks to measure time intervals for long displacements (eqs. 6-7).
c) We need to consider the frame with respect to which we must define the velocity v of the synchronization condition (eq 1). This frame has v = 0 and it plays the role of an absolute preferred frame.
a)b)c) suggest that the Thomas precession is a local effect that cannot manifest for long displacements.
More information in:
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There is a difference between Lorentz transformations and scale transformations.
Special relativity satisfies Lorentzian symmetry due to the constancy of the speed of light and the special relativity principle.
However, in reality, the aether makes the speed of light locally invariant, so the Lorentz transformation is not necessary.
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Planning to use a handy and affordable GPS receiver along with ArcGIS Field Maps for data collection.
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Thank you, Dr. Fareed. I checked their website and found Trimble Catalyst/DA2 with GNSS and Bluetooth option.
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I have widely inaccurate spatial distances in my "Pairwise Spatial and genetic distances written in column form" table output from SPAGeDI 1.5. For example SPAGeDi measures the distance between points -29.325094, 29.707921 and -29.322181, 29.707929 as 0.001178km (Spatial dist (km) column), but they are actually +/- 320m apart! I have entered the lat and long as decimal degrees (Lat = -29.322710, Long = 29.716432) in columns labeled X and Y. I have also specified Num Coords in the second line of my file as "-2". Are the spatial distances something else entirely and not the distance between GPS points?
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I found my answer. My column order was animal ID, Lat, Long, Pop, allele 1, allele 2, ... So I moved the Pop column to after the animal ID and now it's correct with only minor differences.
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I set up a number of control experiments indoors, placing soil samples in a number of boxes with openings above them according to different treatments. I would like to use this multispectral sensor to take pictures of these soil samples indoors, but it seems that it must be used in conjunction with a GPS tool? Is it possible to use it without GPS? It is like a digital camera that can take pictures manually.
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I think you can use it. If it has been installed on a UAV, I suggest you use the UAV to take pictures and avoid damage during the uninstallation. But one trouble you may face, the camera focus distance is set for UAV flying, so when you try to take a picture at a short distance, the image may not be clear enough. Also, the distance between different camera sensors will make the picture shift. I only test the P4M (DJI), it's hard to fix these problems.
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Self-reporting bias is a challenge in case of GPS data collection, in studies where participants have to manually START and STOP recording their trip, unlike studies where GPS data is passively collected (continuously in the background) without the need for user intervention.
I specifically want studies which have mentioned the existence of self-reported bias in the context of GPS data collection.
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I'm still trying to understand your question. In the passive collection, you are referring to a GPS device that is at a fixed location so the deviations in reporting can be seen?
And you are looking for what?
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I want to log GPS/GNSS data on an iPhone/iPad and look for a dedicated app. I want to log as much data as possible (DOPS, satellite data [strength, number, position,...], used constellations, frequencies...) over a longer period of time. Additional data from other internal sensors (IMU) would also be ideal. The recording should not depend on the position change, ideally in NMEA or RAW and stored locally. Other data formats are also possible if they contain the necessary information.
Does anyone know such an app for IOS? I have tried dozens and have not found one that meets the requirements.
Thanks
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Thank you for your answer. The programme works smoothly, even in the combination of GNSS and other sensors. It is also available for iOS and Android. It still has one weakness. GPS/GNSS/Location alone provides the number of satellites, in combination with other sensors this number of satellites is missing. Nevertheless, I will use this app.
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The raw GPS data is useful for various post-processing tasks. What is good source of obtaining raw GPS data in RINEX format?
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I am trying to calculate KDE home ranges for 50 polar bears for a research project. The bears were collared with Argos GPS collars, and each bear has around 200 locations (one location/day).
I am hesitating between using the Least-squares cross validation method (LSCV) or plugin to estimate the h smoothing factor; given my dataset, which of the two would be the best method?
Any advice would be appreciated!
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Cross-validation is a good method but it can take too long if you have 10000 or so. With 50 or 200 there is no problem With it.
You can try also adaptative methods for bandwidth with different sizes for each point.
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What is the position error limit for GPS aided INS sensor fusion for small rockets?
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The issue of grazing is a huge concern for the managers of all the conservation reserves (protected areas: national parks, wildlife sanctuaries). I would like to request my colleagues to provide some efficient ways to map high alpine grazing lands.
Thanks and sincere regards
Gowhar Meraj
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Are there any available datasets of autonomous vehicles trajectories with GPS and date times specifications? if not, how would one adapt existing datasets, which are obtained from normal vehicles, to autonomous ones if possible?
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Here are same datesets for vehicle trajectory prediction/planning:
Argoverse
Appoloscape
NGSIM
HighD
nuScenes
CommonRoad
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Hello guys,
I'm currently doing a research on the working of Track and Trace, since it's a thing that is often used... My school has given us the assignment to look in the working of track and trace. But even though I'm looking a lot on the internet. I can't find a clear description on how it works.
Yeah it works (often) with a GPS signal. But what type of communication is this? Is it encrypted communication or is it unencrypted communication? If it is encrypted what kinda encryption is most likely used?
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Greeting Eric Adema . Firstly, you need to know what that you want to track and trace. For example, if you want to track the target, you need to have two prominent parameters; location of the target and the current location of the vehicle. So, in this situation, the both parameters will undergo several computation in order to get the distance and the heading towards the target. Then, when we talk about the 'trace' the target, the first thing you need to consider is about the movement of the vehicle which is compulsory to identify the velocity, current heading and also the DOF of the vehicle. So, it will have various of computation in order to move exactly towards the target position. GPS is very compatible in order to has the location (Latitude, Longitude) but you need to used the high resolution of GPS.
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I am currently working on a study to estimate the traffic volume distribution of urban areas by utilizing mobile phone location records. Please, can anyone help me to find an open access dataset for the desired task? Your contribution in this regard is highly appreciated!
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Hi,
You can check that...
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I mean besides the official interface control documents provided for GPS, Galileo, GLONASS, and BeiDou, is there a relatively recent document that lists the services broadcasted and the main signal characteristics (e.g. carrier, modulation, chiprate) at least for these global systems?
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Thank you very much
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The L5 signals from GNSS (US GPS/NaVIC/GLONASS) are being explored for wide applications. With focus on assessing the errors in (GPS) location data, what are the fundamental steps involved in determining errors or corrections that are necessary. Key points on validation mechanism.
I am exploring this topic and it will great if specific literature on fundamentals corrections adopted on processing of L5 signals can be highlighted.
Thanks in advance.
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You can read this paper:
Testing GPS L5 Tracking Algorithms and their Impact on Positioning Accuracy
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We're currently planning a pilot study to explore movement behaviour within urban and sub-urban greenspace, as well as the contribution of greenspace-based physical activity to total weekly physical activity. Participants will be given accelerometers to capture movement, but we're looking for a good (but affordable) method of capturing location. Dedicated GPS devices remain prohibitively expensive for this project, with a potential solution available through using smartphone data collection.
I'd be really interested and grateful to receive recommendations for smartphone apps that would facilitate this capture. Naturally, I'm interested in accuracy, but would be willing to compromise somewhat in order to obtain an app that is cross-platform, simple to use and share data, and possesses precedence for research use. The app also needs to be ethically sound with regard to data sharing and privacy. The choice in available apps is overwhelming, and any recommendations would be most welcome, especially those based on experience.
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Also check..Where You at? Using GPS Locations in an Electronic Time Use ...
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For GPS - INS fusion how to find the rotation matrix from body to navigation frame and how the coriolisis and gravity will effect the navigation purturbation equations?
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Dear Varsha:
As Nabil answered, Farrell's Aided Navigation is a good book. Other good books are:
Biezad, D. J., Integrated Navigation and Guidance Systems, AIAA Education Series, 1999
Rogers, R. M., Applied Math in Integrated Navigation Systems, 3rd ed, AIAA Education Series, 2007
Grewal. Weill and Andrews, GPS, Inertial Navigation, and Integration, 3rd ed,
John Wiley 2013
Farrell, James L., GNSS Aided Navigation and Tracking, American Literary Press 2007
Farrell and Barth, The GPS and Inertial Navigation, 1999
For further correspondence with me, you may write to me at IIT Indore,
Also, you may see Sreeja, Professor, in your college, in Electrical Engineering.
I hope all this helps.
Hari Hablani
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If a GPS tracking device is placed on animal, I assume it will more or less affect the movement of the individual. So, is there a way the animal can get rid of the device by itself or everytime you place a device you will need to remove it for the animal later.
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I am not a specialist, I just have a general interest in your interesting question. Here is a page about the ethics of animal tracking with short considerations about removal of the device after the end of the study: https://www.animalethics.org.au/policies-and-guidelines/wildlife-research/radio-tracking
See also this summary of a study: https://www.ucd.ie/newsandopinion/news/2020/july/30/solar-poweredanimaltrackertransformshowresearcherscollectdataonanimalsinwild/ ("Attaching, and later removing, a tracking device to an animal involves capturing, restraining, and in some instances sedation. This process can be stressful for animals. Significantly lessening the impact that such tagging has on the behaviour, health, or welfare of an animal is a paramount concern for researchers.")
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Hello everyone. I am a PhD student at the Czech University of Life Sciences, I am working on the development of data collection collars (tags) for different animals species (and, what is more critical - sizes). At this point, I am looking for colleagues, coauthors and collaborators who are working in the field of animal behaviour and automatic data collection (i.e. accelerometers, gyroscopes, GPS). To continue the development and appliance of animal behaviour data collection devices and analysing tools for that purpose. If you are interested in more details, you can contact me here or by email: fiialkovskyi@ftz.czu.cz
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Dear Pavlo,
Thanks for your prompt reply, so let us start up our joint work on animal behaviors. I am looking forward to hearing from you on this affair very soon.
Thanks in advance,
Takeo
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Given millions of GPS points located in the same area. What would be the least cost method to extract all the neighboring points of each entry in the dataset ( i.e. all the points that are within a given range of another one) ?
It is to be noted that this process will only be done once for the entire dataset.
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I have successfully used kd_tree (https://en.wikipedia.org/wiki/K-d_tree) to create a data structure capable of handling milions of 3D points. There are also some libraries that can help you implement it such as https://docs.scipy.org/doc/scipy/reference/generated/scipy.spatial.KDTree.html
Good luck!
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I work for FL Fish and Wildlife Commission and have 50+ old Wild turkey non-rechargeable VHF and GPS transmitters that no longer work. Does one know what options I have for disposing or recycling them?
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We are going through the same issue. We have decades worth of old, unrefurbishable VHF collars. I contacted the companies and generally, they are Lithium Chloride batteries. We discharge them fully and send them to our HAZMAT contractor for incineration because the batteries are encased in resin and are not easy to remove.
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How can we determine the tangent point (lattiude, longitude, and altitude) from position of LEO and GPS satellites?
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You can find an explanation on how to calculate it in the following link:
that corresponds to the Ph.D. dissertation Contributions to ionospheric electron density retrieval.
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Dear all,
we are preparing a multibeam survey on the Canary Islands and ask ourselves which GPS RTK service would allow for smooth operation near the south coast of Lanzarote. Fugro marine star is not accurate enough, we need a "real" RTK service providing positions in the centimeter accuracy level. Most preferentially we would like to catch the signals via mobile internet near the coastline via NTRIP. We would highly appreciate recommendations or shared experience for canary island surveying ;)
best regards Jens
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Dear all, the issue has been solved. We use online RTK via Ntrip from a local GPS reference stations nearby. The corresponding service is hosted by http://www.grafcan.es/ and a yearly subscription cost 200€ for our academic surveying. The GPS accuracies we obtained ranged between 3 and 5 centimeters and highly improved our MBES measurents
Many thanks and
best regards
Jens
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Does anyone know how can we represent the GPS data acquired over three years from radio-collared deer? Any GIS Software for mapping out home range and seasonal movement without going for excel calculations?
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The best solution is to use R rather than a GIS software for analyzing home range and seasonal movement. GIS is a good tool for keeping and viewing your data. R is designed for analysis. A review paper for animal movement using R can be a start paper. https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2656.13116.
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During field mapping, geographic coordinates are collected using GPS, and later on these coordinates are plotted on the digital geographic map. Then, I would like to have different steps to download the GPS coordinates and plot them on a digital map. thank you
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It would be nice to know whether you desire plotting GPS latitude and longitude as latitude and longitude or in a different format eg. UTM or local coordinates where you are and what package you intend using. Reason being GPS coordinates are spherical coordinates and you are trying to depict them on a flat or planar surface and you cannot directly do that.
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Since I am working on autonomous vehicle, I am interested in developing a path planning/navigation system for guiding in row crops. Please tell me about the type of algorithm/programme that needs to be developed for same. Also, inform me what type of camera and GPS system (Make; Model) for real time application will be the best that can identify the crop rows.
Is there any firm in India which can provide the necessary equipment/components.
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You are welcome. As I had already underlined, I have no knowledge about such cameras. I have never seen such cameras in my hand or any other place. I have not also seen any technical online video in detail about them . I know no detail about the cameras. I only suggested my idea through the theoretical scope. I discriminated between 3D cameras and 2D cameras. I had seen a video from Boston Dynamics Atlas robot and also in TV, in which some cameras render the environment image in 3D scan and can analyze the environment for collision avoidance. A 3D scanner camera is suitable for advanced motion planning. But I guess some simpler cameras you could possibly use for your case. I mean a camera which can distinguish between the rough terrain where the farms are bordered, and the traction where the crops are grown. This could be simply available by a camera which could detect two different colors: color of row crop, and the curb obstacles along borders of any farm. There might be no need for an advanced 3D scanner camera, so long as a simple camera can distinguish dark and light fields and tractions over the farming land based on their color (grey and black). This is all I knew.
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C language
GPS module is neo-blux m6
TivaC123G
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Hello, it's very simple and sources exists of examples.
the difficulties is :
1) wich µC are you using ? UART data buffering is very importante to prevent data lost during serial data transfer
2) wich data do you want ? there are several forms of data depending of GPS sentences frames you are using
I can give you example and at your charge to undestand it and implementing it.
I implementer on mbed LPC1768.
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Hello,
I am looking for an accurate way to measure the surface of agricultural plots with very irregular shapes and less than 1ha.
A potential method is doing polygonations with a GPS or an app on the phone, but it looks like they make 25% error or more when the plots are tiny (100-300 m2).
Do you know of any good alternative I could try?
Thank you very much!
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The first question must be why error of the prediction is higher and how could you reduce that error than finding another method. It is a model and model could be improved by improving the parameters you used to predict! The second question why you are interested to such a lower area or a high resolution. I think sometimes it is better to depend with some levels of error on your model. I recommend you to check your model again and again with ground truth. Otherwise it would be garbage in garbage out. Any model will give you an output based on the the input data. Therefore, knowledge of expertise is highly demanded before you run the model. I want to share you what heard from a man of non-soil scientist in a big conference he said " the soil of area A will be finished within 25 years" based on the model.
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I am interested in products of less than 1 g in weight, for bats of about 10 grams. Thank you for your recomendations in advance.
(Im aware that telemetric transimtors of such weight exist, yet am currently looking into other options)
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We are designing a system that is named as "GPS based traffic monitoring system", that will be helpful in reducing accidents, data collection, traffic congestion avoidance and a lot more. could you please assist me in doing so?
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Dear Mr. Azeem!
I use a case-study approach while searching for resources to answer your question. COVID-19 is a vital factor in this case:
1) Nisar, S., Zuhaib, M.A., Ulasyar, A. et al. A robust tracking system for COVID-19 like pandemic using advanced hybrid technologies. Computing (2021). https://doi.org/10.1007/s00607-021-00946-6 Free access:
2) D’Angelo, G., Palmieri, F. Enhancing COVID-19 tracking apps with human activity recognition using a deep convolutional neural network and HAR-images. Neural Comput & Applic (2021). https://doi.org/10.1007/s00521-021-05913-y Open access:
3) Sowmiya, B., Abhijith, V., Sudersan, S. et al. A Survey on Security and Privacy Issues in Contact Tracing Application of Covid-19. SN COMPUT. SCI. 2, 136 (2021). https://doi.org/10.1007/s42979-021-00520-z Free access:
Yours sincerely, Bulcsu Szekely
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Greetings everyone,
Hope all of you are good in this pandemic situation.
I need some good reference papers and if possible some good ideas which can be useful in the designing of a compact Triple Band GPS/IRNSS patch antenna.
Thanks in Advance.
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Dear
Hadi Nobari
Nobari thanks for giving your valuable time, but the paper you have suggested is not talking anything about circular polarization. The shape they have used is Circular.
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Hello, I was wondering whether there is a non-invasive technique to apply a GPS collar to a wild dog. I was thinking about e.g. a tree hole with some food where they have to put the head through the (elastic) collar to get in, which then automatically attaches to the dog? Or maybe remote controlled (with the help of a camera trap) - like a reversed drop-off mechanism? Or anything else... Thanks!
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Dear Andreas, I'm also interested in this subject, as you suggest I was thinking of placing a collar on specific species path/food trap and use a "necklace trap system". Indeed, the animal will pull his head into the "collar snare" which will adjust the collar to the size of the animal's neck (with a safety catch to avoid any strangeness). Once the pressure is too strong on the cable/elastic used, the trap will break and the animal will be released with the collar. A safety system on the collar itself will have to be put in place to avoid a too important strangulation (elastic?). Or a system that wears out over time, allowing the collar to fall off after a while. The trap could be monitored by GSM camera trap to verify the proper conduct of the operation, in case of problem a rescue operation could be deployed quickly as the camera trap will have sent the images.
For other burrowing species, I thought of a tube at the exit of their burrow that would force them to borrow the latter. In the tube, a mechanism would allow a plate previously coated with special glue to stick to the back of the animal.
Of course the security of the animals must be the priority and these are only ideas to be developed and tested.
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I'm working on a project which will involve using a mono-camera or stereo-camera and accelerometer to detect the location of an object(as offline GPS). I want to implement the data form camera and sensor in an embedded system with algorithm to get the location. I know, there are many embedded system like beaglebone, raspberry pi and stm32.
so my question :
What is the best way to start selecting a suitable embedded system for this project?
Hopefully, somebody can guid me in the right direction.
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Oliver Krohn
Sorry for the late response. Thanks for your help
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Hello Experts,
I want to know that how to find theta maximum when i am using GPS and sphere and surface type distribution. and using cosine distribution.
then i want to know that is there any mathematical calculation to find theta maximum for biasing.
like in the Geant4/examples/advanced/radio-protection theta maximum is 0.003 deg. how they got this using the surface area of source or object. like how can i get for my object ?
any type of help will be appreciated.
Thanks in advance !
Best Regards
Priyanshu
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My research is related to the Ionospheric disturbances for an earthquake, and the point of my question is after I calculated and plotted the Ionospheric Pierce Point (IPP) & Sub-Ionospheric Point (SIP) trajectories, and the values of STEC and their anomalies from the closest satellite to the epicenter of an earthquake area by using several observation stations from sugar, I stopped on the step of calculating or plotting the STEC & VTEC for all my GPS stations because I don't know even I don't have the Matlab script for it. (please provide me a full Matlab script for it) with thanks
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Hello
I want to find accurate locations of some static objects to be used as landmarks for localizing other mobile object. As the landmarks will be used to localize other object, their own location must be accurate. Kindly suggest some practical methods for accurate positioning of static objects(landmark).
Best regards
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@tariq islam .Use dead reckoning.it is the process of calculating current position of some moving object by using a previously determined position, or fix, and then incorporating estimations of speed, heading direction, and course over elapsed time.
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Are global navigation satellite signals like GPS, Glonas, Navic, or Galelio received under water ? Can Radio frequency signals penetrate underwater ? Up to what depths ? If not then what sensor systems are used for navigation?
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Thank you so much Marc Schmieger and Recep Turan
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I need to collect driving data such as speed, battery SOC, GPS location, ambient temperature, elevation for a specific EV ( say Renault Zoe), but I'm not sure what is the best way to do this and what I would need.
Many studies have used OBD-2 loggers. There are other cloud-based technologies like Geotab or Airbiquity. Also, I wonder if there are any mobile apps that can fulfil these requirements.
Thank you.
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Hilal Yılmaz You can try dedicated vehicle tracking products (eg. Teltonika, Ruptela, ATrack, Tkstar, TrackingFox, SkyPatrol, GoSafe, Concox, Dolphin, Meitrack, Tramigo, Quecklink, Galileosky, etc). Check the highlighted options and you'll be able to choose the most closest to your needs. We use Teltonika telematics products in our fleet tracking solution called FLEETware. Details about Teltonika options: https://teltonika-gps.com/products/vehicle-tracking/
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Tell me about the apps you can’t live without
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Hi
The UTM Geo Map software is so good for android.
Goodluck
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In the U.S., Executive Order 13905( Federal Register : Strengthening National Resilience Through Responsible Use of Positioning, Navigation, and Timing Services) signed 02-12-2020, ordered several federal agencies to conduct vulnerability assessments related to critical infrastructure. I'm looking for qualified opinions / research on the potential for degradation or loss of access to GPS / GNSS to potentially impact critical infrastructure at hydro-electric dams.
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Well, 'Yes'. And not just the obvious spatial difficulties, it is the reliance on timing signals. The epicenter is NIST: Overview at https://www.nist.gov/news-events/news/2021/02/nist-finalizes-cybersecurity-guidance-positioning-navigation-and-timing and from there are other domain specific documents like https://www.nist.gov/news-events/news/2019/08/situational-awareness-electric-utilities-nist-publishes-cybersecurity
Behind all these is usually quite a paper trail of conference presentations, meeting transcripts, etc. from stakeholders providing input, usually referenced in the bibliographies of the documents. The exceptions are, obviously, classified content with specifics on actual incidents and unresolved current vulnerabilities.
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I am preparing a grant and would like to collect 24-hour HRV at multiple time points. I'm looking for affordable, validated devices that would be ideal for my study- and importantly, they cannot have GPS capabilities. I cannot use any of the devices I am familiar with, and I am not having much luck with identifying other possibilities. Any suggestions would be much appreciated!
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Design some novel device based on photoplethysmography (PPG) and record the data in a data storage chip. and then access the recorded data as per your convenience.
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Hi,
I need to calculate the abundance of a single species from the occurrence data collected from the field. It is not possible to record every GPS co-ordinates for the species in an area more than 250 square kilometres. Is there any apt method to estimate abundance, like random replacement model?
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Thanks for your time for me. My query is on finding out the (X,Y) coordinate of an IMU (Using 6050 MPU) mounted object (Without any GPS).
While performing the task we are getting fluctuating acceleration data how can we resolve it?
It will also be very helpful if you suggest any other MPU for better performance.
Thank you
With regards,
Bhaskar
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Make sure you are using some sort of low-pass filter for the acceleration integration. You also want to ensure you properly calibrate the sensor. I cover calibration of the MPU6050 with the AK8963 magnetometer (MPU9250 package) in a recent tutorial:
I cover using a Butterworth filter for stabilizing the acclerometer output. I also show double integration of the acceleration to approximate displacement. The MPU6050 is a fairly good choice. There is also a more recent sensor (ICM-20948) which is considered a replacement for the MPU9250. Here is an example smoothed output of the calibrated and integrated acceleration:
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I have a problem in which a right hand circular polarized wave (GPS wave) encounters an ideal smooth plane obliquely, and then is reflected off that. To solve this kind of problems, the wave is decomposed into two perpendicular linearized polarization (vertical and parallel or S and P) and then the reflection coefficient of each component is calculated through Fresnel formulas. But I want to calculate an overall reflection coefficient for above mentioned right hand circular polarized wave and I could not find any method for summation of two vertical and parallel components in any reference.
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Dear Dr Ijaz:
Thanks in advanced.
As you know when a wave have an oblique incidence with a plane, to calculate Fresnel reflection coefficient, the wave is decomposed into two S and P polarization (referred to "https://www.brown.edu/research/labs/mittleman/sites/brown.edu.research.labs.mittleman/files/uploads/lecture13_0.pdf" ) and then Fresnel reflection coefficient for each of S and P polarization is calculated separately. and I am seeking for a way to calculate the sum of these two reflection coefficients (note that we can not use arithmetic sum). because I need the overall reflection coefficient.
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I have time series GPS tracking data from a number of individuals, all with varying time between locations (i.e. certain individuals recording at 15 minutes intervals, others at 20 minutes or 1 hour). Tracking starts at sunrise and ends at sunset, omitting overnight locations. I would like to subset the data to 1 hour to make it comparable. I am currently doing this in excel although it is proving to be a rather tedious method. Is there a method in R that can speed up this process?
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There is a easy way to do this in PYTHON.
The function called "resample" and "groupby" are most used function for time series analysis.
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How I use GPS in the field of agricultural mechanization to select appropriate machinery or technology based on soil, field, and crop condition?
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Excellent Question Dr. Md. Anwar Hossen. I Follow
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I have some GPS data for Iran. their stable framework is Arabia. for comparison them with other GPS data, I need to change their framework into Eurasia instead of Arabi. Is there any suggestion for this conversion except calling the authors?
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Finding the datum is a more involved process than transforming data into a different datum. At issue is how the data are collected and how the GPS system works. If you consider that you are starting with a coordinate system that is earth-centered and earth-fixed (ECEF)with without reference to a surface, in other words, one that is solely based on the orbital mechanics of the satellites, this starts to make a bit of sense. These "ECEF" data are transformed using a reference datum, which in turn has a reference ellipsoid (describing the shape of the Earth for the purposes of measurement) to provide points in the described space, that usually correspond to "points on the ground". If you know the working datum and reference ellipsoid, you can recreate the ECEF parameters and transform the data to another reference system, but without the starting point it is nearly impossible.
gerry
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I am trying to implement Kalman filter to get rid of multipath error points on GPS data while my data contains Latitude, Longitude, accuracy, altitude, speed and time. I am using python but unable to figure out how can I choose parameters for solving this issue.
Guidence will be very much apreciated.
Thanks in advance
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Why not learn the parameters from some training data
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How to increase GPS Receiver Power without increase the supply? Only the physical structure.
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You need to use a receiver digital antenna array. She increases SNR by digital beamforming on the basis of Fast Fourier Transform.
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We want to conduct a boat survey and need to track the trajectory and need to register the location and time of animal sightings. The logger should have a decent battery life, at least for 3 or more days.
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Thank you for your constant help Hayder Dibs . Garmin GPS will be costlier for us, because we want to deploy those on fishing vessels and there is hardly any network out in the sea, so I doubt how effectively will cellphone GPS work.
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I want to install GPS trackers on hare (Lepus timidus).
What I need is probably an GPS/GSM logger, weight approx. <50 g
·        Is there someone here, having experience in this kinds of work?
·        How works the GPS-collar – What is the price - How reliable are they?
·        Is it some company/web page you can recommend?
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HI, I am interested in experience regarding brown hare (Lepus europaeus) tracking devices.
When is the best time to set up a tracking device for brown hare that need to be released from the rearing farm in to the hunting ground.
It is clear before we release him, but there is a fear that he will under huge stress during fastening on. Is there any safe way to do this?
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Hello, I have mapped the locations of several individuals of a certain species of bird. I have the GPS coordinates, the date and the time data every half hour for several consecutive days and I am trying to apply the Package 'mkde' to get the kernel density maps based on the movement (home range). Is there someone with experience in using this package who can help me?
Thank you very much!
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Alas, don't know that program. But there are a number of others that might serve your needs including the density analytics in, for example, the ESRI tools like ArcGIS and ArcPro.