GLONASS Ambiguity fixing without 1230 message

Q&A forumGLONASS Ambiguity fixing without 1230 message
G. Thalmann asked 1 month ago

What must be the content of the RTCM 1033 (Receiver description) message
so the F9P can go into the RTK-fix state?

3 Answers
clive1 answered 1 month ago

As far as I’m aware the receiver recognizes and number of makes/models. Realistically you’ll probably need to open a support ticket with uBlox to get at the specifics.
FW 1.12 had references to TRIMBLE, NOVATEL, LEICA, SEPTENTRIO, SPECTRA, TOPCON, JAVAD, so it might have awareness

How best to achieve compatibility with RTCM 10403.3

AndrewRL answered 1 month ago

To get a F9P rover into fix with a third party base without MT1230

  1. Make sure the F9P is using firmware 1.13 as that update claimed to improve the handling of MT1033
  2. If you have control of the base. make sure it is also using the latest firmware

If that doesn’t work try narrowing down the issue – eg can you get into fix without GLONASS, eg decode the RTCM from the base with the free version of SNIP to see if there is anything odd. 

G. Thalmann answered 2 weeks ago

Andrew, I did what you suggested. Clive, you are right! I did some tests with one GNSS only. Result: The F9P needs minutes instead of seconds to get into rtk-fix state, even with more than 7 satellites Without the rtcm 1230 message the GLONASS Ambiguity won\’t be fixed. I made attempts with several 1033 messages: an empty one, one with  ADVNULLANTENNA and a fully equipped like: Station details for stream:   Solothurn   NTRIP Agent NTRIP_RTKLIB/demo5_b33b2 Receiver Type  u-blox ZED-F9P Receiver Firmware   1.00 HPG 1.13  SerialNo: F1100000943 Station Identity  2 Antenna Antenna Descripton  TWI3870+GP Used For  Tallysman 33-3870 GNSS Antenna SerialNo  20190314  Setup: 1  ….. Msg Format  RTCM 3.2 Messages  1005(5), 1006(10), 1008(10), 1033(10), 1074(1), 1084(1), 1094(1) Count  242,671 total msgs  ~6.2 (msg/sec) Signals  GPS: Yes      GLO: Yes      QZSS: No    GAL: Yes      BeiD: No     WAAS: No    SV Counts  GPS:12  GLO:9  QZSS:0 GAL:9  BeiD:0  WASS:0 Common GNSS Osc.  Yes Conclusion:  Use rtcm 1230 message when GLONASS is enabled for maximum performance                    I think we have to wait for more infos from ublox and for the next firmware release.                    Have a good new Year 2021!