MIKE LAUTERBACH DID A TEST ON THE LOCK ON ROAD GPS FEATURE

Lock on road setting on GPSMAP276C Courtesy Donald P

Lock on road setting on GPSMAP76 Courtesy Donald P

The following recordings were made by Mike in his tests :-

GPS download with Lock on road engaged (T4A V3.4.2 map active)

Datalogger with Lock on road engaged (SAStreetmap active)

Datalogger with Lock on road engaged (T4A V3.4.2 map active)

..\Download files\Lock on road tests.gdb

GPS download with Lock on road engaged (SA Streetmaps selected)

The objective was to determine the effect of this setting on GPS accuracy. Mike had the following comments to make.

I have just tested the "lock-on-road" settings:

I used 2 GPS's - my GpsMap76 with data logger attached, and a StreetPilot 2610, as I wanted to determine the accuracy of the latter.

I had T4A maps loaded on both units, and could not get either to lock onto the roads, even when I disabled the T4A maps, leaving only the base map active.

I then loaded SA Streetmaps, and SA City Select, and both units locked onto these maps. As suspected (known?) by Donald and Andre, the tracks saved on both GPS's were locked onto these inaccurate roads.

The saved track log on the datalogger was accurate (unaffected by the lock-on-road setting of the GPS)

The saved waypoints were also unaffected and accurate, on both units.

What should please the compiling team (Bessie, take note, and inform Wouter
:-) is that lock-on-road has no quality implications on the tracklogs downloaded from the GPS units, as long as the T4A maps are active. At least this is true for both the GPSMap76 and SP2610. I don't think that different zoom levels have any bearing on the results. This is also an encouragement for T4A members to obtain dataloggers if they can, as the results from these dataloggers are unaffected by GPS settings, such as the lock-on-roads settings.

Even though the SP2610 is a nice "navigational toy" only, its accuracy was pretty much on par with that of my GPSMap76. However, I did not find any settings on the 2610 where recording intervals can be set. Is this possible?

Regards
Mike