Science topic
Global Positioning System - Science topic
Related to GPS research and applications
Questions related to Global Positioning System
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.
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?
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?
I need GPS location where noise level data (in dB) is measured for Delhi, Mombai, Kokata, bengaluru in excel/text format.
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.
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) ?
We are currently working on the drones project and looking for GPS datasets for drones under spoofing and jamming attacks.
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.
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
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.
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.
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.
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.
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?
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
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.
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?
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?
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.
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 ?
I would like to calculate the strain rates from horizontal velocities obtained from data processing of GPS permanent stations .
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:
Planning to use a handy and affordable GPS receiver along with ArcGIS Field Maps for data collection.
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?
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.
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.
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
The raw GPS data is useful for various post-processing tasks. What is good source of obtaining raw GPS data in RINEX format?
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!
What is the position error limit for GPS aided INS sensor fusion for small rockets?
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
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?
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?
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!
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?
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.
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.
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?
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.
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
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.
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?
How can we determine the tangent point (lattiude, longitude, and altitude) from position of LEO and GPS satellites?
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
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?
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
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.
C language
GPS module is neo-blux m6
TivaC123G
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!
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)
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?
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.
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!
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.
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
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
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
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?
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.
Tell me about the apps you can’t live without
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.
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!
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?
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
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.
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?
How I use GPS in the field of agricultural mechanization to select appropriate machinery or technology based on soil, field, and crop condition?
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?
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
How to increase GPS Receiver Power without increase the supply? Only the physical structure.
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.
The weight should not exceed 1 g and be pretty small, so that a 15-20 g-shrew can carry it. Thank you!
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?
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!