On Sun, Jan 25, 2009 at 5:22 AM, Martin Erzberger <martin@erzberger.ch> wrote:

In "binary" mode the precision signals are converted into a number of statistical values, such as "EHPE" (estimated horizontal position error). These values cannot be "turned back" into the NMEA protocol's HDOP, VDOP and PDOP (the HDOP is retained in

Different vendors compute DOP differently, so "converting" these values is problematic.

For these tasks, gpsbabel performs well, with some limitations:

1. It loses precision in the conversion run (e.g. from 00838.2842 to 00838.284)

 Where is this, the NMEA output?

2. It drops all satellite information (satellites visible in the $GPGSA record, all of the $GPGSV records)

Fundamentally, GPSBabel processes positions reported by a GPS and isn't terribly interested in which SVs were used in the reporting of that position.  So you're correct that if that information is critical to you, you need to keep it out of GPSBabel's reach because we will discard it.