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Hello All,
does anyone know of any free software on sharing and compatibility between Satellite systems and IMT-2020 network?
Please let me know if any with possible URL link.
Kind regards.
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Dear Sajor, I think there is not a ready made software that can be used to directly give the interference between the satellite earth stations and the mobile transmissions. As software suit i can propose for you to use matlab to solve this problem. You can model the system and its form its signals and then study the interference between the two communication systems. Bu as i know there is frequency allocation and assignment such that the interference is avoided between the two systems. The bands assigned for the satellites is different from the bands assigned for the mobile communications. Best wishes
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Hello Pablo.
You are interested in my work "Modernization of the Weinberg’s Converter for the Implementation of a Charge-Discharge Device in the Power Supply System of a Spacecraft"
This work was written during the implementation of the research project "Energy-transforming complex of a spacecraft with direct digital control" commissioned by "Information Satellite Systems" named after Academician MF Reshetnev. My group created a model that passed successful tests. It is mathematically proven and shown on simulation models that it is possible to implement a digital control system in terms of speed not inferior to analog control systems. And when implementing adaptive control, it is possible to realize the speed of the feedback loop exceeding the speed of the feedback loop implemented on analog elements.
After the end of the project, I moved to work in another organization (Novgorod State University) where I became the head of the engineering center. Unfortunately, "Information Satellite Systems" did not want to work with this university.
Is your organization interested in direct-digital spacecraft power conversion systems? I will be glad to cooperate.
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Dear Vagiz Kabirov,
I suggest you to see links and and attached file on topic.
Methodology to synthesis of digital regulator for solar battery ...
ESPC2019 (30 September 2019 - 4 October 2019) · Indico at ...
https://indico.esa.int › event › timetable
preparation of the camera-ready versions of your paper for the ...
View PDF - Nasa
Space-based solar power - Wikipedia
https://en.wikipedia.org › wiki › Space-based_solar_po...
Best regards
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I need to know which satellite system able to capture imagery at differnt time, solar and sensor zenith and azimuth angle?
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Dear Ashim
thank you so much
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Dear all,
I am trying to use Kaplpana solar radiation data from Indian satellite system. If anybody have some automated software which can convert several .hdf5 files in to geotiff format. If some one have matlab code for data conversion (.hdf5 to geotiff) this may also be valuable.
I need an automatic one because data volume is very high.
I will be thankful to you all.
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May this paper help you!
Regards!
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monthly data of groundwater estimated using satellite system, I can download the data but it seems to work with special kind of data reader, anyone can help?
data can be dowloaded from here
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Hi,
There are no such things as ‘GRACE images for groundwater’. GRACE mainly detects the time-variable component of the gravity field, which is often interpreted as changes in water storage. Depending on your study area, there might be different water storage components to consider (surface water, groundwater, glaciers, soil moisture, and snow). After subtracting some of the components, the residual represents the remaining ones. Post-glacial rebound, important seismic activity, and petroleum/gas extraction can also influence the signal.
For ready-to-use GRACE data (called ‘solutions’, as they all have assumptions), here is one of the most recent:
Best
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STK Analyzer tool is an awesome tool for designing an experiment. I tried to use it for selecting both the constellation and orbital parameters based on the elevation angle between the ground stations and all the satellites in a constellation. Using macros in Analyzer may be a way, but it needs more participation from specialists. Hence, any thoughts?
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use the matlab and stk. define your parameters in matalb then simulate in stk and save data in matlab
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What happened with the images of Sentinel-1B? I tried to download it in ESA site and we can download just images of october 2016. Something happened with this platform? Someone knows why?
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It depends on your research. Here are the differences
Level-1 Single Look Complex (SLC) products consist of focused SAR data geo-referenced using orbit and attitude data from the satellite and provided in zero-Doppler slant-range geometry. The products include a single look in each dimension using the full TX signal bandwidth and consist of complex samples preserving the phase information.
Level-1 Ground Range Detected (GRD) products consist of focused SAR data that has been detected, multi-looked and projected to ground range using an Earth ellipsoid model. Phase information is lost. The resulting product has approximately square resolution pixels and square pixel spacing with reduced speckle at the cost of reduced geometric resolution
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In GPS precise point positioning (PPP), we get several corrections from IGS. My question is about how to utilize these corrections in an accurate way.
1. Is there a free software to interpolate orbits and sat. clk from SP3c file? I want these results not the final positioning solution.
2. Is there is an automatic way (via software)  get the satellite antenna phase center offset and variation?
3. Do we need to use the earth rotation parameters if I am doing my code in the ECEF frame and not transforming to inertial frame?
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Just to clarify, I am somehow now  able to answer my questions:
1. some commercial software like Bernese is doing the interpolation. However, doing my own code for Lagrange interpolation of order 9  gave me very good results. 
2. I couldn't find an online tool to read the atx file, but with some coding skills and following the format of the file, we can make a code for ourselves. Otherwise, the Phase center offsets can be take copy and paste from the file knowing its location there (this is not good if it will be needed frequently).
3. No, we don't. (It might be needed in the tidal and other detailed corrections, still not sure but to reach the centimeter-level accuracy, you don't need it as long as you work in the ECEF frame.
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How to find the delta V for phasing maneuvers of a micro satellite constellation in a circular LEO? I have found deltaV using Hohmann transfer but the value is too large for the cold gas propulsion system of small satellites to handle.
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Hi do not have a reference of the impulsive case, but you will find attached a paper describing what happels in the low-thrust case. The formulas giving the natural evolution of the right ascension of the ascending node are given in this paper.
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Different materials have different spectral signatures.
Is the spectral signature different for a given solar panel, depending on whether it is charging a (spacecraft's) batteries or there is a full charge and the panels are heating up? I would expect that certain wavelengths be absorbed more when charging and either reflected or contributing more to increasing temperature once the batteries are fully charged. I am neglecting any system to dissipate the surplus power (e.g. a nanosatellite with a simple power subsystem). I would also expect this effect to be fairly small for the overall spectral signature of a particular satellite, given the other materials composing the satellite.
Thank you in advance for contributing to this discussion.
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Alex,
No. The emissivity and albedo (and more particularly) the spectral reflectance profile are not influenced by the state of charge (SOC) of a craft's internal batteries.
Several reasons lead me to this.
1) The batteries are, in general, 'hidden' from the PV arrays - there are DCDC chargers between the arrays and the batteries.
2) The movement of electrons in a PV junction does not alter the optical characteristics of the array.
Certainly, if the arrays are generating current, they will warm from Joule heating - but they're in sunlight (otherwise there's no current...) and have a low albedo - so solar insolation will dominate (probably) that source of power.
In any case, a hot PV array is well-modelled (I reckon) as a blackbody - and so all you'll know from a spectral emission profile is the temperature of the array.
There's probably a body of literature out there on the reflectance spectra of various array types. 
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Perturbation acting on a LEO remote-sensing satellite may shift its ground track. Can we find the ground track error after certain days IN STK?  
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Seyed, did you find out how to do that on stk?
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Dear All
As we know any flying object like LEO Satellite or UAV its elevation angle of antenna of a ground(Earth) receiver starts from some value reaches a peak (maximum value) when flying object is just above your head then it starts decreasing and decreasing after some time it reaches below the earth surface and or elevation reaches zero .
Now we take an example of a signal tracking  of low earth orbit satellite satellite. suppose we have a signal receiver at ground and trying to receive the satellite signal. as the elevation angle increases the received signal strength increases, this strength keep increasing as the elevation angle keep increasing . the strength of signal reaches maximum value when the satellite is just above our head after that satellite elevation decreases so the receive signal strength reaches a minimum value at minimum elevation.
the requirement is mathematical formula which provide relation between receive signal strength and elevation angle.
I found paper attached which derived probability density function of elevation angle .how can I use this pdf function in order to get the receive signal strength(or SNR) from this pdf formula. do we need another formula or some changes is required to this formula.
I shall be very grateful for help.
Regards
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Hello Shakeel,
The K in my equation is for Kelvin. I was trying to indicate that TA the result of the calculation is a temperature in Kelvin. I'm afraid this text box does not work well for equations.
For a reference I recommend
Satellite communications systems / Gerard Maral, Michel Bousquet
This equation for Noise Figure will allow you to derive the relationship between the elevation angle (α) in my first equation to S/N. Again, this text box does not work well for equations. However, you should be able to find this equation in any EM or antenna text.
F= (Si/Ni)/(So/No) = No/(GNi) = No/(GkTAB) = 〖GkTA B + N)+R]/(GkTA B)
• Ni = kTOB is the available noise power at the input
• F       is the Noise Figure of the receiver
• Si        is the available signal power at the input
• So     is the available signal power at the output
• TA       is the temperature of the antenna in Kelvin
• NO      is the available noise power at the output
• NR      is the noise added by the receiver
• G       is the available gain of the receiver
• B       is the effective noise bandwidth of the receiver
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The ground tracks of a single satellite cross each other after a certain time. At the intersection of two ground tracks (called crossover) the altimeter system allows to observe the sea surface twice. If the sea surface would not change, the sea surface heights derived from measurements of both ground tracks should be identical. In reality, the difference of sea surface heights (the so called crossover differences) do not vanish due to errors of the orbital height
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Hi Doha,
the main contributions to crossover differences used to be orbit errors. For Geosat and the ERS-satellites crossover adjustment/crossover height minimization was used to constrain the orbit solutions. However, not only the orbit errors are minimized but also long-wavelength sea level signals.  Nowadays, with much more tracking data, greatly improved gravity field models and better dynamical modelling it is not used any further.   A commonly used alternative method is to adjust the ERS/Envisat data to Topex/Jason data. If you use ERS (and Envisat) data you might want to check  whether  crossover adjustment (or something else) has been used for the specific orbit model.
Hope that helps, Saskia
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Most of the GSO(Geo synchronous orbit) satellites operate in L band  and/or  S band. What makes the bands convenient for satellite communication?
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All GPS signals are in the L-band of the frequency spectrum ( 1–2 GHz). Because L-band waves penetrate clouds, fog, rain, storms, and vegetation, GPS units can receive accurate data in all weather conditions, day or night. There are circumstances in which GPS units may not receive signals accurately, such as inside concrete buildings or under heavy forest canopies.
The choice of the GPS carrier frequency (to transport data signals) was submitted to the following requirements:
• Frequencies should be below 2 GHz, as frequencies above 2 GHz would require beam antennae for the signal reception.
• Ionospheric delays are enormous for frequency rages below 1,000 MHz and above 10 GHz.
• The PRN codes (explained in the Glossary) require a high bandwidth for code modulation on the carrier frequency. Therefore, a range of high frequencies with the possibility of a high bandwidth had to be chosen.
• The chosen frequency should be in a range where the signal propagation is not influenced by weather phenomena like rain, snow, or clouds.
Based on these considerations, the choice of L-band frequencies proved to be advantageous. Each GPS satellite (Block IIF and beyond) transmits three carrier signals in the microwave range of the electromagnetic spectrum, designated as L1, L2, and L5 (frequencies located in the L-band between 1,000 and 2,000 MHz of the spectrum). The L1 frequency is 1,575.42 MHz (wavelength 19.05 cm), the L2 frequency is 1,227.60 MHz (wavelength 24.45 cm), and the L5 frequency is 1,176.45 MHz (wavelength 25.48 cm).
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am designing a Patch Antenna to be used on a small satellite in LEO orbit, For protection i am using a Delrin as a Radome of (75x75x3)mm dimensions. As delrin is an insulator it is susceptible to charge storage, Can you guide me as to what sort of material/coating/paint should i use for ESD protection without affecting my Radiation, as most of the Paints/coatings available for ESD have high conductivity and as per my understanding they are not microwave transparent.
Also for the size mentioned above at LEO orbit is it necessary to cater for ESD, The Delrin is fixed to the satellite body with eight screws.
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ESD should not be an issue in LEO.  The ionospheric plasma will prevent charge buildup unless the voltage is impressed onto a conductor by a power source.   That won't be the case for Delrin, a good insulator.  You may require a coating with the proper solar absorptivity and emittance to control the thermal situation.  Also, if in LEO an extended period of time the atomic oxygen environment in LEO is very chemically reactive.  An inorganic thermal control coating may be used.  These are available in industry.
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I am beginning research into using Earth observations to identify current streams and water bodies in Idaho. I am looking for suggestions/recommendations for different satellites and sensors to use that I may have not know about. Thanks in advance. 
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Please have a look at the discussion following Mustak Ali's question "Can we automatically classify only the rivers from satellite images using any programming or different methods?", last year on Research Gate.
Open water you can map with both optical and radar remote sensing, but flooded forest you see much better on radar imagery. In optical imagery you may  see some texture differences between the flooded and the non-flooded forest, which is more related to forest type and its location in the floodplain, but with radar you can map the actual extent of water below the canopy at that particular time. Have a look of at the use of SAR imagery over the Amazon forest to find examples. You can add "varzea" or "flooded forest" or "floodplain" to limit the results.
Success,
Wietske
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Need a calculation method for it.
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The dimensions for a solar sail rather depend on what the sail is to be used for. In sailcraft built to date (IKAROS, NanoSail, LightSail), the purpose was primarily demonstrating stowage and deployment of a sail, and so size was chosen to be whatever was convenient for the stowage and deployment method, given the spacecraft bus size and design. (Don't get me started on how fundamentally useless it is to test-fly a stowage and deployment method that works for large mass:area ratios, but doesn't scale to sufficiently small ratios!)
For future operational solar sail missions, the sail size will have to be large enough to produce a large enough spacecraft acceleration, for whatever mission the spacecraft is meant to carry out. While there are a few useful missions that can be done with relatively small sails (e.g., NOAA's proposed GEOStorm mission), most require a mass:area ratio of 20 grams/m^2 or less, preferably 10 grams/m^2 or less, in order to be able to produce sufficient thrust. So, if you have (say) a 6U cubesat that can have a maximum total mass of (say) 8 kg, you'd want to carry a sail with an area of at least 400 m^2, preferably 800 m^2.
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what is position of fasteners in cubesat? and why it is that? what is position of pcb in cubesat? and why?
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I was wondering if it is possible to estimate the torque provided by actuators, given satellite attitude measurements (w & q)? 
We only have access to measurements from satellite attitude (w and q) and we need to figure out what is the applied torque to the spacecraft (excluding disturbance) to the satellite at each time step.
Assume the satellite is not controlled and is under a pre-defined input voltage to its actuators. 
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I figured a way out. Thanks. and sorry for the late reply.
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I want to simulate a large flexible satellite and test it in the space conditions. What's the best software in this field?
I built a satellite in ADAMS but I couldn't apply orbital dynamics on this satellite. I want to imort it to a software in which I can analysis its behavior in the LEO orbit.
thanks for your responses.
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Do you want to simulate the orbit of the satellite?
Can you be more specific?
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Get IF samples from Receiver...
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Priyanka, please see the first link below. If you wish to record your own data, you need a special GNSS front-end (see the second link).
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It is announced that positional accuracy of Landsat-8 /OLI: 12 meters circular error, 90-percent confidence, and TIRS  - 41 meters circular error, 90-percent confidence. I cannot find the same characteristics for previous Lansats. Can anybody help?
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Many thanks to everybody! I know the real practical positional accuracy basing on  20 years of Landsat images interpretation with the help of field works. It is really about 30 meters (or even less, when it is possible to find a point inside a pixel!). I search an approved published data on this subject. The most close is this link:  Tucker, Compton J.; Grant, Denelle M.; Dykstra, Jon D. NASA’s Global Orthorectified Landsat Data Set // Photogrammetric Engineering & Remote Sensing, Number 3 / March 2004, pp. 313-322(10)  http://www.landcover.org/library/pdf/PERSMarch_04_313-322.pdf
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    Construction ground control station China's Beidou navigation satellite system (BNSS) should not be confined to mainland China to engage in, nor should engage only in Asia and the Pacific Ocean region.
     This system should be extended to the poles (Antarctic and Arctic) region, which is in line with the needs of the Beidou navigation technology.
Conform to improve the accuracy of the Beidou navigation satellite system monitoring and control requirements, naturally also in line to improve the measurement and navigation accuracy.
      From a technical point of view, building a reasonable distribution of the Beidou navigation satellite system tracking station, the necessary monitoring stations worldwide.
     I wonder that  while  BNSS  is ready to serve customers around the world,its monitoring , control and other sites on the quantity if will meets the demands ,until 2020?
     If these sites are not satisfied (even temporarily) requirements, how to make up for its shortcomings it?
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Hello. I would suggest a political solution to the problem of global satellite navigation systems: we should discontinue the current obsession with nation states and combine all existing systems into one system (GPS, Galileo, Beidou, ...). Naturally the governments of all involved countries must agree. Collaboration beats competition :-)
P.S. You may be interested in a paper on GNSS integrity modelling in the link below.
Disclaimer: All comments are my own and do not reflect the views of my employer.
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I am working on development of attitude determination and control system for imaging nanosatellite. For the same, I am required to calculate the pointing requirements, given the sensor specifications.
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Basically, pointing accuracy is same order-of-magnitude value as IFOV. Must be more accurate if you aim for sub-pixel resolution and less accurate if some image smear is tolerable. 
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I'm doing a project on optical communications between small satellites, however, I feel the general term given by Wertz of up to 500kg/1000lbs is quite vague and seems somewhat unnecessarily large. Using the http://satellitedebris.net/Database/UCSDB.php I found that out of the 1,000 odd satellites listed 568 had civil and/or commerical users and the mass ranged from 0.8kg to 6,910kg. 145 of those satellites were under 500kg, but, it seemed to jump to 689kg and above, leaving no medium/middle sized satellites. I would therefore, suggest saying less than 300kg. Additionally, Straub, J(2015) mentioned in his article In Search of Standards for the Operation of Small Satellites that only 14% of the university Cubesats were greater than 40kg. It just seems quite out of proportion to the advancements we have today to say 500kg is small.
Do you agree? Disagree? What is your opinion of this?
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Susie, to your original comment, "It just seems quite out of proportion to the advancements we have today to say 500kg is small" -- small is relative.
Current geosynchronous communications satellites are pushing 7000kg; by comparison, 500kg is pretty small. What we call "small" is also a reflection of how satellites are launched -- and the <500kg satellites are typically going up on smaller launch vehicles, or as secondary payloads.
It's also a reflection of relative cost -- small sat missions are generally much less expensive than larger ones (partly, but not entirely, driven by the launch cost.)
By comparison to nanosats (such as CubeSats) 500kg seems huge... but to those looking from the other end of the range, 500kg is not so large. Ultimately, the number used is a bit arbitrary. 180kg, for example, comes out of the max mass allowed for an ESPA-compatible secondary payload. 500kg is just a convenient round number.
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Is there any simulation tool available to check that the proposed IC design would work in all kind of environments, including space? I want to check the effect of radiation on the chips that we use in space satellites.
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There is a free Silvaco webinar ¨Simulating Total Dose, Prompt Dose, Damaging Fluence and SEU using TCAD¨  on 17th February.
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I would like the images to cover the most devastated areas in NYC.
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In case you haven't found these aerial photos yet:
Click on Sidebar, then Download to get the photos. These photos are also on Google Earth.
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The positioning coordinate of a laser footprint is decided by many factors, not only including the location and attitude of satellite platform, but also laser ranging. Before the lauching of a satellite laser altimeter, how do you build up the model to describe the impact of these factors?
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I believe you have probably faced such problems with the Icesat laser altimetric satellite. Regarding this issue I think that the following Algorithm Theoretical Basis Document and paper can help you to explain better the positioning error:
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I am using a DELTA G3T receiver and use it for real time data logging using GREIS commands directly to PC. For the purpose, I use NetView software.
I can record GPS only/ GLO only/ GAL only or any combination of the constellations without problem using GREIS command sets.
Now, I want to log data for any of the constellation for single and dual frequency modes - as the rcvr supports triple freq for GPS and dual freq for GLONASS and GALILEO.
1. Can anybody please tell me how to operate the receiver in single frequency and dual frequency modes using GREIS command sets
2. Can anybody please provide me the the real implications of the "satellite status" (0/ 1/ 2/ 3 etc.) shown in the measurement screen (attached below). As suggested in manuals:
0 - CA/L1 data used for position computation
1- P/L1 data used for position computation
2- P/L2 data used......
3- ionosphere-free combination used .....
So, if the status is shown to be '0' - does it mean it operating in single freq (L1 only) for position solution ?
and if the status is '2' then the rcvr is using L1+L2 (dual freq opeartion) ?
and if the status is '3' then the rcvr is using all available freqs for ionospheric correction ? >>>> AM I RIGHT OR OTHERWISE ?
The manuals are not sufficient for clear understanding of the issue.
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I am not familiar with Javad receivers but I believe that '00/01/02/03' refer to what type of measurements (code and phase) from a specific satellite is used to compute the navigation solution. The use of code and phase measurements depends on the positioning mode. For example, on Single Point Positioning mode, the receiver may use: C/A-code, P1-code, P2-code or a combination of P1 & P2 known as iono-free combination. If I remember correctly something: (f1^2*P1-f2^2*P2)/(f1^2-f2^2) with f1 and f2 being the broadcast frequencies, while P1 and P2 the code measurements. Please notice that the above formula works only for P-code. If the receiver provides C1 or C/A code instead of P1, one needs to apply differential code biases or DCB C1-P1. This is an significant aspect for high-precision application.
Now back to your attachment. Your screenshot indicates that the receiver operates in a stand-alone mode. Although the receiver tracks a number of signals, the real-time navigation solution is based solely on C/A-code. The settings for real-time positioning and raw data logging are two different things. Just enable the right parameters and you may be able to record all those signals for later post-processing. Otherwise, change the positioning computation mode (e.g., RTK) to also use the carrier phase measurements for your real-time positioning solution. However, in the later case the rover receiver needs to fetch an additional stream from a base station.
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Sample values for the rain dsd are also appreciable. I am struck with my project please help me with this. Thank you
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The number of elementary precipitable drops depends,not only on the number of activated droplets, but also on the size distributions of those droplets.Calculations
made by Howell and by Neiburgerand Chien show that drops which grow only by condensation develop toward a uniformsize. East hasshown that, if condensation an d coalescence occur simultaneously, development of auniform drop size would not normally be expected.
Ifthedroplet sizes just after condensation tend toward uniformity, the high concentration of droplets will actually break the colloidal stability. Then the concentration of droplets,rather than size of the individual droplets,will be more important in determining the concentration of precipitable drops.
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I am interested in 3.9 and 10.8um wave bands, in particular, to study cloud properties
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These should be available from EUMETSAT data portal. See the list of available observations at:
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SCIAMACHY which is onboard the Envisat has 3 different modes of measurements. (link : http://www.iup.uni-bremen.de/sciamachy/instrument/modes/index.html) . In Nadir it is easy to understand that location is beneath the sensor. But in limb or occultation mode if we consider some measurements what location does they belong to (in the sense geo-location of the measurement) as the measurements here are tangent to atmosphere.
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For SCIAMACHY limb measurements, see e.g. this paper:
Accounting for the effect of horizontal gradients in limb measurements of scattered sunlight
J. Puķīte, S. Kühl, T. Deutschmann, U. Platt, and T. Wagner
Atmos. Chem. Phys., 8, 3045-3060, 2008
We hope to publish a paper soon that contains a discussion on the effects of inhomogeneous or "small" aerosol and cloud layers (small in comparison with the instruments field of view) on limb reflectance. I will keep you informed, if you're interested.
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I am starting research in the field of trace gases and I wanted to make a comparative study of satellite data with ground based observation as well as their percent contribution. For this purpose, I have chosen ozone measurements. What I understand from literature is that first we need to get total columnar ozone data vide OMI and subtract the value of stratospheric columnar ozone vide MLS from total columnar ozone to derive tropospheric columnar ozone. Thereafter I could calculate percent contribution of surface ozone to tropospheric columnar ozone and tropospheric columnar ozone to total columnar ozone. However, for this purpose I need stratospheric columnar ozone and total columnar ozone, of which I have total columnar ozone but I am unable to derive stratospheric columnar ozone. Can you please suggest how to derive stratospheric columnar ozone without writing program and downloading the data to MS-Excel?
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Thank you for your responses
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It seems that Galileo PFM and FM2 are transmitting alert pages on E5. I also find that my CRC implementations fail on E1. Perhaps they are not broadcasting valid navigation data, or maybe the I-F-nav format has changed?
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Hi Manuel, thanks for responding. We are using the OS SIS ICD, Issue 1.1 September 2010, it seems to be compatible, but over the last few months, it seems that PFM and FM2 are not transmitting nominal pages. I hear that a group at Technische Universitaet Muenchen have decoded messages on FM3 E5 this week. We are awaiting the satellite to pass overhead today so that we can try. Have you decoded a TOW recently?