Question

Does anybody knows which algorithm wheresat GPSTK function uses to calculate range, when we give the antena position.

-- ErlyLima - 10 Nov 2013

Answer

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Hello,

Wheresat uses standard ICD-GPS-200 equations to do Geodetic computations when calculating range.

Recently, a bug was found and fixed in wheresat. The gpstk package with the fixed wheresat can be found at http://sourceforge.net/projects/gpstk/files/Misc/gpstk_win64_wheresatfixed.exe/download.

-- BryanParsons - 12 Nov 2013

Hello, The question is because I calculated the range by myself using the satelites position given by wheresat function and note that there was a diference about 2c(Clock Correction) in the range. Is it correct? I tried to instal the new version "gpstk-2.2.win64" but there is a problem and the function wheresat don´t run in win7 "the program spoted run" and also in win8 it gives the menssage "The program can't start because MSVCP110.dll is missing from your computer". Thanks for the replay.

-- ErlyLima - 24 Nov 2013

Hello,

The version of Wheresat in the version you downloaded is currently not working. You can download the GPSTk with a working copy of Wheresat here: http://sourceforge.net/projects/gpstk/files/Misc/gpstk_wheresat.exe/download

This is a near complete version of GPSTk v2.3 and contains some fixes for specific applications. Before installing, please uninstall all previous GPS Toolkit installations.

Also, prior to running the applications, please make sure to have a copy of Microsoft Visual C++ Redistributable for VS2012 installed on your computer, which is required to run the applications. This can be downloaded here: http://www.microsoft.com/en-us/download/details.aspx?id=30679

-- BryanParsons - 25 Nov 2013

First of all, I would like to thank for your attention. The new version gpstk_wheresat.exe that you've suggested has worked fine in win8, but in win7 it only worked if i opened the command prompt in the installation directory (note that the the path variable is set correctly) work. By the way I've got my file with satellites position and the range. This time the distance between the satellite and the antenna is same that I've calculated manualy in other words: the difference between the two coordenates satellite and antenna, plus the satellite Clock Correction by light velocity. I just have two considerations to do. The first one is that the satellite positions isn't the same in the two versions, is now it corretct or is better recalculate to check it. the second is that in the newer version disappeared some PRNs, so i think there are still a bug.

Best regards,

Erly Lima

-- ErlyLima - 29 Nov 2013

Hi Erly,

Somehow, I missed answering you back...I apologize and blame the holidays.

Thank you for the feedback, which we will use to assist us in our current development efforts for a new testing framework for the toolkit. This will help to address the accuracy and bug issues you experienced with Wheresat and any other applications.

Thanks for your interest in the GPS Toolkit.

-- BryanParsons - 06 Feb 2014

Hi Erly. Glad that now there is agreement between gpstk's results and your hand calculations. It seems that resolves the present issue, so I'm taking the liberty of setting the status in the form to answered. If that's not the case, you might want to open a new ticket with details abiyt the "disappearing PRNs".

-- FelipeNievinski - 26 Jun 2014 No such template def TMPL:DEF{PROMPT:supportquery}

Topic revision: r7 - 26 Jun 2014, FelipeNievinski
 

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