I'm using an M8P to track the position and velocity of a vehicle (RTK fixed). I recently moved from NMEA to UBX since UBX has support for reading the velocity vector in the NED frame (UBX-NAV-PVT) and NMEA seems to be lacking this. I'm using the NMEA $GPGST message to obtain the standard deviation for latitude, longitude and altitude. I noticed that UBX lacks support for the standard deviations or am I overlooking something? The closest I could find were the hAcc en vAcc attributes in UBX-NAV-PVT. I'm guessing these are standard deviations (1-sigma) but I could not confirm this from documentation. hAcc seems to be a combined latitude longitude deviation so, hAcc should be roughly sqrt(sigma_lat * sigma_lat + sigma_long * sigma_long). Could someone please confirm this for me, or point me to a resource? Thanks!