GPS output is not included in --prefix-out because it depend on hcxdumptool.
In other words:
You must run hcxdumptool with connected GPS receiver and option --use_gpsd
--use_gpsd : use GPSD to retrieve position
add latitude, longitude and altitude to every pcapng fram
hcxpcaptool will add a GPS position to every received packet.
tshark and wireshark is able to show you the positions (and more) directly from the pcpang file:
$ tshark -r test.pcapng -Y frame.comment -T fields -E header=y -e frame.number -e frame.time -e wlan.sa -e frame.comment
172 Mar 6, 2019 23:01:48.793212000 CET 1a:f8:7c:91:24:a3 lat:49.126337,lon:4.626268,alt:129.500000,date:06.03.2019,time:22:01:48
If you run hcxpcaptool with option -g on such a pcapng file, you will get a GPS track (inclusive WiFi information).
-g <file> : output GPS file
format = GPX (accepted for example by Viking and GPSBabel)
Viking understand and show you the track. GPSBabel is able to convert it to other formats.
BTW 1:
Do not try to run hcxpcaptool -g option on cap or pcap files. This (ancient) format doesn't allow additional comment fields.
BTW 2:
hcxdumptool use gpsd. So GPS receiver must be supported by gpsd (
https://gpsd.gitlab.io/gpsd/index.html)
BTW 3:
What do you mean GPS does not work?
If you are on a kernel > 4.19, bluetooth may not work like expected, because some
external devices are affected by an xhci issue:
https://bugzilla.kernel.org/show_bug.cgi?id=202541#c32
That means, if your device is connected via USB bluetooth adapter, it may not work as expected.
