GPH 692 South Lake Tahoe Field Exercise 2012

GPS Work

Pre-Field Prep

I used the National Geodetic Survey datasheet website to download locations of known elevation points.

The monument locations were converted into a GIS for spatial comparison and location data management.

The Equipment

ProXH

Recon

Antenna

Using this field equipment each station was observed for 2 to 12 minutes depending on satellite availability and tree cover.

Data Collection

Date and location information

Pre processed location info and elevation

Distance and bearing from GPS recording station to the gravimeter recording station.

Results

• The recon unit created 9 files foe each recorded station.

None of these files were of a type that was readable.

• The Recon unit works in unison with Trembles Pathfinder

processing software

• The pathfinder software would not import the data from the

recon unit.

• These data could not be entered manually

• Trimble would provide zero customer support on this issue

Results cont…

When we compared the Recon pre processed data to known monuments in the area an error of roughly 17 meters was found.

This requires post processing of the field data to provide useful elevation information for use by the gravity group

Results cont…

Due to field data being recorded on paper while at each

recording station the lat long location information was

able to be used for position data for the gravity group

who used it in conjunction with the LIDAR data to obtain

elevation information at each station

Suggestions for future work