2 very closely related questions about differential correction with a Garmin unit:
1). Some data was collected using a Garmin GPSMAP 76Cx unit and the data collectors are interested in whether post-processing differential correction is possible. Does anyone know if this model of unit supports this kind of functionality?
If I'm understanding this right (and please correct me if I'm wrong), various brands of GPS units collect a whole slew of information behind the scenes as they record points and save this in a proprietary format, such as SSF for Trimble. This is then convertible to a universal RINEX format using software (sometimes open-source?), which is then used to do post-processing differential correction. Does the Garmin GPSMAP 76Cx produce this kind of file, equivalent to, say, an SSF file on a Trimble Juno SB? I can't seem to find any such information in its detailed specs.
2). If there is no such background info collected by the unit, is any kind of post-processing differential correction possible to data collected by this unit? It may even be the case that the data collectors didn't create any points on the unit but simply wrote down the time and coordinates it displayed. As I understand it, RINEX / SSF / whatever files contain a lot of other info -- the exact "GPS time" (as opposed to local or UTC time) when each point was taken, satellite configuration and pseudo-range, a Doppler shift based on whether a satellite is approaching or retreating, number of satellites detected at time of collection, etc. etc.
Presumably if you don't have a unit that's doing all this for you, or you don't even bother to log the point on the unit but just write down the coordinate & time, you're out of luck if you want to do post-processiong correction?
Would be great if you all could confirm! Thanks so much.