The code generates only 1000 PRN code chips however, the actual code is 1023 chips long why is that so ?

[Imtiaz08]

@scateu @edy555 @sgk @laf0rge @Mictronics @osqzss

[osqzss]

The C/A code length is defined as CA_SEQ_LEN in gpssim.h:

/! \brief C/A code sequence length /

define CA_SEQ_LEN (1023)

[Imtiaz08]

Yes, but when I am debugging the code there are only 1000 elements only

Also can you please tell me why are you taking only subframe 5 and subframe 1 to generate the Dwrd in the GenerateNavMessage function?

[Imtiaz08]

[osqzss]

https://stackoverflow.com/questions/57921875/debugging-in-vscode-watching-vectors-with-length-1000

[Imtiaz08]

Thank you so much sensi can you please answer the second question? i.e. why are you taking only subframe 5 and subframe 1 whole generating the navigation message? Also, are you calculating all the values in decimal? because again in the debugger we can see the decimal values only

[osqzss]

Please ask Google first. https://stackoverflow.com/questions/39973214/how-to-display-hex-value-in-watch-in-vscode

[osqzss]

All the subframes are updated when generateNavMsg() is called:

int generateNavMsg(gpstime_t g, channel_t *chan, int init) { ... for (isbf=0; isbf<N_SBF; isbf++) { // update subframes here. .... } }

[Imtiaz08]

so basically the eph2sub function converts ephemeris into the subframe and the generatenavMsg function updates the message right?

And I am sorry for not making myself clear enough... Actually, I am implementing the code in Matlab for my MS thesis so I would like to know whether the navigation message is being generated in binary format or it is converted into decimal before writing it to bin file

[Imtiaz08]

@osqzss sensi, I am using Matlab to write the generated binary data into a file. Can you please provide me any insights on this?

[osqzss]

https://www.mathworks.com/help/satcom/ug/gps-waveform-generation.html

[shuwang1]

so basically the eph2sub function converts ephemeris into the subframe and the generatenavMsg function updates the message right?

And I am sorry for not making myself clear enough... Actually, I am implementing the code in Matlab for my MS thesis so I would like to know whether the navigation message is being generated in binary format or it is converted into decimal before writing it to bin file

I think they are always in binary, not in decimal, because binary operations, e.g, checksum, are involved.

[Imtiaz08]

@shuwang1 But the values are always shown in decimal when using VS code