Open jonathanmuller opened 1 month ago
I would have to do some tests to confirm this, not sure when I will have time for that. Can you show what difference that makes in the delay in some realistic cases?
At my current location, time, and with uBlox provided klobuchar parameters, the current version return 4.53[m], and the corrected one 5.98[m].
It seems RTKLib is also using the power 3 calculation : https://github.com/rtklibexplorer/RTKLIB/blob/d2030fbfc8ae71f83d1481dba7b9ad6b4b14b794/src/rtkcmn.c#L3606
Here is some calculated values based on my position (Switzerland) with various elevation / azimuth All values are in meters :
25% quartile | 50% quartile | 75% quartile |
---|---|---|
1.2 | 1.3 | 1.8 |
Azimuth | Elevation | Current Output (Power 2) | Corrected Output (Power 3) | Difference |
---|---|---|---|---|
π/0 | π/0 | 12.6 | 16.9 | 4.3 |
π/0 | π/1 | 5.8 | 7.9 | 2.0 |
π/0 | π/2 | 3.8 | 5.2 | 1.3 |
π/0 | π/3 | 3.7 | 5.0 | 1.3 |
π/0 | π/4 | 2.5 | 3.4 | 0.9 |
π/1 | π/0 | 13.2 | 16.4 | 3.2 |
π/1 | π/1 | 6.1 | 8.0 | 1.9 |
π/1 | π/2 | 3.9 | 5.2 | 1.3 |
π/1 | π/3 | 3.7 | 5.0 | 1.3 |
π/1 | π/4 | 2.5 | 3.4 | 0.9 |
π/2 | π/0 | 11.6 | 14.3 | 2.7 |
π/2 | π/1 | 6.2 | 8.0 | 1.8 |
π/2 | π/2 | 3.9 | 5.2 | 1.3 |
π/2 | π/3 | 3.7 | 4.9 | 1.3 |
π/2 | π/4 | 2.5 | 3.4 | 0.9 |
π/3 | π/0 | 11.6 | 14.3 | 2.7 |
π/3 | π/1 | 6.2 | 8.0 | 1.8 |
π/3 | π/2 | 3.9 | 5.2 | 1.3 |
π/3 | π/3 | 3.7 | 4.9 | 1.3 |
π/3 | π/4 | 2.5 | 3.4 | 0.9 |
π/4 | π/0 | 13.2 | 16.4 | 3.2 |
π/4 | π/1 | 6.1 | 8.0 | 1.9 |
π/4 | π/2 | 3.9 | 5.2 | 1.3 |
π/4 | π/3 | 3.7 | 5.0 | 1.3 |
π/4 | π/4 | 2.5 | 3.4 | 0.9 |
Will double check next week with my tests and merge if that looks good! Thanks for the help!
Klobuchar model is defined as
But specification ( https://www.gps.gov/technical/icwg/IS-GPS-200H.pdf ) requires amp and per to be
So the 3rd element is currently multiplied by phi to the power of 2, rather than phi to the power of 3
Shall I open a PR ?