ublox F9P - rover: no RTK fix with default gpsd ublox initialisation

[Michael Haberler]

hello,


for my use case I'd want an RTK fix as well as track information - both 
together do not work for me (is there any reason why it should not?)

without the gpsd "--passive" option, I only get an 3D DGPS fix but get track 
info 

if I run gpsd with "--passive" I go get an RTK fix but no track info in cgps -s 
:

{"class":"TPV","device":"/dev/ublox-zed-f9p","status":4,"mode":3,"time":"2022-10-10T12:01:45.000Z","ept":0.005,"lat":47.129118667,"lon":15.212016667,"altHAE":865.1,"altMSL":822.4,"alt":822.4,"epv":60.95,"magvar":4.1,"speed":0.021,"climb":0,"epc":121.67,"geoidSep":42.7,"eph":48.45,"sep":69.92,"dgpsAge":1,"dgpsSta":163}


if I force a NAV-PVT message with 'ubxtool -z CFG-MSGOUT-UBX_NAV_PVT_USB,1', I 
get two TPV messages in a row - the above message and this one - note 
confusingly fix is 3D DGPS, despite the above message just sent:

{"payload":{"class":"TPV","device":"/dev/ublox-zed-f9p","status":2,"mode":3,"time":"2022-10-10T12:01:45.000Z","ept":0.005,"lat":47.1291187,"lon":15.2120166,"altHAE":865.066,"altMSL":822.409,"alt":822.409,"epv":0.847,"track":0,"magtrack":4.1262,"magvar":4.1,"speed":0.021,"climb":-0.034,"eps":0.27,"epc":61.56,"geoidSep":44.866,"eph":0.859},"_msgid":"df3d6f0f24891046"}


how should I go about this? 

just take track from the second TPV, or take position from first TPV and 
calculate track manually?

thanks,
Michael



setup: 
- F9P with RTCM3 fed to UART1 via str2str 
(https://github.com/rtklibexplorer/RTKLIB/tree/demo5/app/consapp/str2str)
- UART1 set to 115200 ubxtool -z CFG-UART1-BAUDRATE,115200
- rtcm feed:  /usr/local/bin/str2str -in 
ntrip://XXXXX:YYYYY@euref-ip.net:2101/GRAZ00AUT0 -out serial://rtcm:115200:8:n:1
- gpsd connected to USB port of F9P
- gpsd 3.24 build from source 0dbc9e
- RTK fix if run with GPSD_OPTIONS="--passive --speed 460800 --debug 1 
--listenany --nowait"
- 3D DGPS fix only if GPSD_OPTIONS="--speed 460800 --debug 1 --listenany 
--nowait"
- UBXOPTS=-P 27.31
- firmware:

{"class":"VERSION","release":"3.24","rev":"3.24","proto_major":3,"proto_minor":15}
{"class":"DEVICES","devices":[{"class":"DEVICE","path":"/dev/ublox-zed-f9p","driver":"u-blox","subtype":"SW
 EXT CORE 1.00 (0fa0ae),HW 00190000","subtype1":"ROM BASE 0x118B2060,FWVER=HPG 
1.32,PROTVER=27.31,MOD=ZED-F9P,GPS;GLO;GAL;BDS,SBAS;QZSS","activated":"2022-10-10T12:12:47.561Z","flags":1,"native":0,"bps":460800,"parity":"N","stopbits":1,"cycle":1.00,"mincycle":0.02}]}
{"class":"WATCH","enable":true,"json":false,"nmea":true,"raw":0,"scaled":false,"timing":false,"split24":false,"pps":false}

happy to provide any ublox config - not sure how what to retrieve and how