GPS-TEC analysis program (version 3.5)

  GPS-TEC analysis program ver 3.5

This application is a useful & very simple tool in deriving the Ionospheric TEC from the GPS raw data, from both RINEX 2 & 3 observation files (Seemala G.K., 2023). Currently it allows only ionospheric TEC derivation from GPS, TEC values from other GNSS will be included in the near future update after testing.

Download program link --> GPS_Gopi ver-3.5 (zip file)

This update fixes few bugs, and updated web links for download of Navigation and DCB files. 

You have to unzip the downloaded zip file into a folder, the program does not need any installation as it is portable executable file. 

If the program does not run or gives an error on your Windows PC/laptop, you may have to install install visual studio redistributable. It can be downloaded from the following link (not included in the zip file).

Download directly from here vc_redist.x86 OR from the following webpage:

About Microsoft Visual C++ Redistributable

Please read brief details and instructions from the "GPS_TEC Readme.pdf"  document which is also inside the above zip file. 
Let me know if you have questions at my email address, please find my email in the above pdf document. 

The description of GPS-TEC program algorithm is published in the following chapter, you may go through it and please cite it when you publish your work using this program.

Gopi K. Seemala (2023), Chapter 4 - Estimation of ionospheric total electron content(TEC) from GNSS observations, Editor(s) : A.K. Singh, S. Tiwari, In Earth Observation, Atmospheric Remote Sensing, Elsevier, 2023, Pages 63 - 84, doi.org/10.1016/B978-0-323-99262-6.00022-5.

Thank you,
Gopi Seemala

GPS-TEC analysis version 3 (for rinex 3 version)

 GPS-TEC analysis program version 3 analysis application

This application is a useful tool in deriving the GPS-TEC data from the RINEX 2.1 & RINEX 3.02 observation files. But, currently it supports only TEC derivation only from GPS, TEC from other GNSS will be included in the future update.

Download program link --> GPS_Gopi_ver_3.zip

Update in this version: can read and process rinex 3 files  and few minor bugs fixed like navigation file location update. 

Also, please install visual studio redistributable from the following link (also included in the zip file) in your PC if the program does not run or windows gives an error.

Download vc_redist.x86 from the following link

https://support.microsoft.com/en-in/help/2977003/the-latest-supported-visual-c-downloads

Please follow the instructions from the "GPS_TEC Readme.pdf"  document which is also inside the zip file.
Let me know if you have questions at my email address, please look it up in the above pdf document.

Thank you,
Gopi Seemala

GPS-TEC program Ver 2.9.5

GPS-TEC analysis application (another minor update -- 2.9.5)
This application is a useful tool in deriving the GPS-TEC data from the RINEX 2.1 observation files.

Download program link --> GPS_Gopi_ver 2.9.5.zip

Update in this version with few minor bugs fixed:  Ftp address of the DCB code bias files were updated to ftp://ftp.aiub.unibe.ch/CODE/ instead of  old address (ftp://ftp.unibe.ch/aiub/CODE/2008/) which is not working.   Now the program can download DCB code files automatically where the PC is connected to internet.

To manually download the DCB code bias files into the data folder:
1. Go to website  ftp://ftp.aiub.unibe.ch/CODE/
2. select the year, then select files P1C1yymm.DCB.Z and P1P2yymm.DCB.Z (yy – 2 digit year, mm – 2 digit month)

Next update will be with rinex 3.03 support and GLONASS, GALILEO TEC derivation, will follow in few weeks.


Please follow the instructions from the "GPS_TEC Readme.pdf"  document which is also inside the zip file.
Let me know if you have questions at my email address, please look it up in the above pdf document.

Thank you,
Gopi Seemala

Rinex GPS-TEC program Version 2.9.2

GPS-TEC analysis application (another minor update -- 2.9.2)
This application is a useful tool in deriving the GPS-TEC data from the rinex observation files.

Download program link --> GPS_Gopi_ver 2.9.2.zip

You can update to this version 2.9.2 temporarily. 
Only minor bugs fixed from version 2.9.1 
- Average TEC file (.std) is fixed now, and has smoothed values.
- In the .cmn file the precision of time is increased  to 6 digits from 5 digits, so as to resolve seconds much better.

TEC from GLONASS is not processed, will be introduced later.

I am in the process of updating (to version 3.0) which would fix biasing errors that appear occasionally with some datasets.
Please follow the instructions from the "GPS_TEC Readme.pdf"  document which is also inside the zip file.
Let me know if you have questions at my email address, please look it up in the above pdf document.

Thank you,
Gopi Seemala

GPS-TEC analysis application (minor update to 2.9.1)

GPS-TEC analysis application (minor update to 2.9.1)
This application is a useful tool in deriving the GPS-TEC data from the rinex files.

Download program link --> GPS_Gopi_ver 2.9.1.zip

You can update to this version 2.9.1 temporarily. 
Only minor bugs fixed from version 2.9 - 
- program excludes the entire data at times when it assumes there are mixed satellite observables (from GPS, GLONASS). TEC from GLONASS is not processed, will be introduced later.

Yet, there are some receiver bias calculations problems to be fixed, occasionally like negative TEC values, bad TEC values, not good convergence in the diurnal trend etc. After fixing those bias problems,  I will post the updated program (version 3.0).

Please follow the instructions from the "GPS_TEC Readme.pdf"  document which is also inside the zip file.
Let me know if you have questions at my email address, please look it up in the above pdf document.

Thank you,
Gopi Seemala

Rinex GPS-TEC program Version 2.9 (Intermediate version, updated version 3.0 will follow soon)

GPS-TEC analysis application
This application is useful in deriving the GPS-TEC data from the rinex files.

Download program link --> GPS_Gopi_ver 2.9.zip

You can update to this version 2.9 temporarily.
But, there are some receiver bias calculations problems to be fixed, that arise occasionally like negative TEC values, bad TEC values, not good convergence in the diurnal trend etc. After fixing those bias problems,  I will post the updated program (version 3.0).

I have included this intermediate version which has some fixes not much relating to scientific part; as many of our colleagues are facing the couple of problems with version 2.2, one common problem is:
-- Program some times hangs, doesn't respond -- mostly because of the incorrect format in navigation file - solved to some extent, if you still see this ver 2.9, remove the navigation file and the program will automatically download the correct one from IGS service webpage.

Please follow the instructions from the "GPS_TEC Readme.pdf"  document which is also inside the zip file.
Let me know if you have questions at my email address, please look it up in the above pdf document.

Thank you,
Gopi Seemala

Rinex GPS-TEC program Version 2.2

This application is useful in deriving the GPS-TEC data from the rinex files...

PS.  As the files are shared to all, the files are zip files are now password protected to avoid any virus.. write an email to me to receive the code to unzip the files.. 


Few issues fixed from version 2.0, let me know if you notice any problems or suggestions.

You can download the program v2.2 in the following two ways..  (List of all files)

1) Download the following GPS_Gopi.exe to your PC or laptop
GPS_Gopi.EXE

2) Run the file GPS_Gopi.exe to extract the files, browse the path where you want to extract, for example to your desktop

-------------- OR ----------------

1) Download the following GPS_Gopi.ZIP file to your PC or Laptop

GPS_Gopi.ZIP

2) Unzip the files into a directory (say folder "GPS_Gopi")

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

3)  Please follow the instructions from the "GPS_TEC Readme.pdf"  document which is also inside the either of the zip archives!
4) You can leave a comments here or email me..  if you have any questions..


This version updates:
Additional capabilities like handling multiple files in a folder (i.e., to process data of couple of days, a month, a year or everything in directory) and few fixes to known issues.

Next update:

There be a major update to this program  with some known issues to be fixed (like unable to fix biases when there are data breaks or it is too noisy), and a brief explanation about data analysis done here with references.