Checking of the updating Pseudorange Offset using API

Hi @pmleveel and @Grace,

I used the command “sim.call(SetMultipathForSV(“L1CA”, svId, 0, pseu_off, 0, 0, 1, id))” to update the PseudoRangeOffset in multipath condition. The pseu_off was computed from the satellite elevation and vehicle altitude and updated after every 1ms.

I printed the value of pseu_off just before calling the above sim.call(SetMultipathForSV… command. I’ve noted that the value of pseu_off was increasing and decreasing frequently as expected. However, during the experiment while the .ip data was generating, the displaying value in the field of Pseudorange Offset of the Skydel’s GUI (photo attached) is always increasing and not same as the value of pseu_off that was printed on the computer screen.

image

Your checking and clarification about this matter would be much appreciated.

Happy Easter!

Thanks,

Phu

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Hi @phule,

Hope you are doing well :).

Could you please provide us with more info on the options you have activated during your simulation because I am not sure to understand your mention about .ip data, do you mean .iq data?

I sent you an email about it.

Regards,
Grace

Hi @Grace ,

Thank you very much for replying to me. Apologies for the confusion. Yes, I meant the .iq data.

I’ve replied your email and attached the python script in .txt file that the .iq data was generated and the pseu_off was computed and updated on Skydel’s Graphic User Interface.

Best Regards,
Phu

Hi @phule,

Thank you for your reply.
I was able to run your script and try to figure out the problem you mentioned.
In fact, I found that the values ​​displayed by the Skydel GUI were consistent with the values ​​sent by your python script.
Because initially, depending on the elevation of each of your visible satellites, your script will calculate a first pseudorange offset value. Then this value will increase (or decrease) very slowly depending on the direction of movement of each satellite.
This is normal behavior. The elevation changes very slowly during a simulation. This is what makes the pseudorange value appear to slowly increment in the Skydel GUI. Also, if I take a screenshoot of the simulation at a given time and compare the displayed value of the pseudorange in the Skydel GUI with the calculation of the script, I notice that they are equal (see SV ID 14 in Skydel GUI and last value of GPS-echo1-14 computed by the script in command prompt):

I have emailed you more details.

Regards,
Grace

Hi @Grace ,

Thank you very much for your helpful clarification. I’ve re-run my code and noted similar to what you have explained. It is clear to me now. I’ve just had another question that was sent you by email. Hope to receive your feedback.

Best regards,
Phu

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