About PPP calculation with GLONASS observations

[flex0902]

I use PPPIGS positioning with COD0MGXFIN products (BRDCxxx.rnx , xxx.BIA xxx.SP3 xxx.CLK). If I want to include the GLONASS observations into PPP, the GLONASS satellites are usually identified "- edit - satellite unhealthy svh=1". I tried to trace the origins and it is in the "def satposs" in ephemeris.py (line 549 - 556).

        if len(nav.eph) > 0:
            eph = findeph(nav.eph, t, sat)
            if eph is None:
                svh[i] = 1
                continue
            svh[i] = eph.svh
        else:
            svh[i] = 0

In the above section, the eph for GLONASS satellites will get "None", the calculation will ignore GLONASS observations.
Follow the "def satpos", also in ephemeris.py.
Above section should be modified as:

    if sys == uGNSS.GLO and len(nav.geph) > 0:
        geph = findeph(nav.geph, t, sat)
        if geph is None:
            svh[i] = 1
            continue
        svh[i] = geph.svh

        if sat not in nav.glo_ch:
            nav.glo_ch[sat] = geph.frq

    elif len(nav.eph) > 0:
        eph = findeph(nav.eph, t, sat)
        if eph is None:
            svh[i] = 1
            continue
        svh[i] = eph.svh

    else:
        svh[i] = 0

Finally, PPPIGS calculations will use GLONASS observations.
In the log file you will see something like this:
.....
2023-10-01 00:00:00 R04 - init ambiguity RL1C -99.588
2023-10-01 00:00:00 R04 - init ionosphere -5.192
2023-10-01 00:00:00 R05 - init ambiguity RL1C -89.002
2023-10-01 00:00:00 R05 - init ionosphere -6.825
2023-10-01 00:00:00 R19 - init ambiguity RL1C -174.356
2023-10-01 00:00:00 R19 - init ionosphere -5.606
.....
2023-10-01 00:00:00 R04 - init ambiguity RL2C -110.139
2023-10-01 00:00:00 R05 - init ambiguity RL2C -86.647
2023-10-01 00:00:00 R19 - init ambiguity RL2C -123.895
......
2023-10-01 00:00:00 R05-R04 ion RL1C (149,148) -0.996 -6.825 -5.192 10.000 10.000
2023-10-01 00:00:00 R05-R04 amb RL1C (366,365) 0.187 0.187 -89.002 -99.588 30.000 30.000
2023-10-01 00:00:00 R05-R04 res RL1C (104) -3.012 sig_i 0.003 sig_j 0.007
2023-10-01 00:00:00 ztd ( 3, 3) -0.371 0.000 0.100
2023-10-01 00:00:00 R05-R19 ion RL1C (149,163) -0.998 -6.825 -5.606 10.000 10.000
2023-10-01 00:00:00 R05-R19 amb RL1C (366,380) 0.187 0.187 -89.002 -174.356 30.000 30.000
2023-10-01 00:00:00 R05-R19 res RL1C (105) -1.602 sig_i 0.003 sig_j 0.004
2023-10-01 00:00:00 ztd ( 3, 3) -1.370 0.000 0.100
2023-10-01 00:00:00 R05-R04 ion RL2C (149,148) -1.646 -6.825 -5.192 10.000 10.000
2023-10-01 00:00:00 R05-R04 amb RL2C (583,582) 0.241 0.240 -86.647 -110.139 30.000 30.000
2023-10-01 00:00:00 R05-R04 res RL2C (106) -3.029 sig_i 0.003 sig_j 0.007
2023-10-01 00:00:00 ztd ( 3, 3) -0.371 0.000 0.100
2023-10-01 00:00:00 R05-R19 ion RL2C (149,163) -1.650 -6.825 -5.606 10.000 10.000
2023-10-01 00:00:00 R05-R19 amb RL2C (583,597) 0.241 0.240 -86.647 -123.895 30.000 30.000
2023-10-01 00:00:00 R05-R19 res RL2C (107) -1.600 sig_i 0.003 sig_j 0.004
2023-10-01 00:00:00 ztd ( 3, 3) -1.370 0.000 0.100
2023-10-01 00:00:00 R05-R04 ion RC1C (149,148) 0.996 -6.825 -5.192 10.000 10.000
2023-10-01 00:00:00 R05-R04 res RC1C (108) -2.982 sig_i 0.313 sig_j 0.726
2023-10-01 00:00:00 ztd ( 3, 3) -0.371 0.000 0.100
2023-10-01 00:00:00 R05-R19 ion RC1C (149,163) 0.998 -6.825 -5.606 10.000 10.000
2023-10-01 00:00:00 R05-R19 res RC1C (109) -1.586 sig_i 0.313 sig_j 0.425
2023-10-01 00:00:00 ztd ( 3, 3) -1.370 0.000 0.100
2023-10-01 00:00:00 R05-R04 ion RC2C (149,148) 1.646 -6.825 -5.192 10.000 10.000
2023-10-01 00:00:00 R05-R04 res RC2C (110) -2.990 sig_i 0.313 sig_j 0.726
2023-10-01 00:00:00 ztd ( 3, 3) -0.371 0.000 0.100
2023-10-01 00:00:00 R05-R19 ion RC2C (149,163) 1.650 -6.825 -5.606 10.000 10.000
2023-10-01 00:00:00 R05-R19 res RC2C (111) -1.591 sig_i 0.313 sig_j 0.425