209 – GPS Site Calibrations
Background: Many times we wish to use our GNSS receivers on sites that are coordinated using an assumed or local datum. This means the coordinate origin maybe N10,000 E10,000 with a magnetic bearing base. Trimble field and office software makes it easy to work in these local systems without laborious rotation and translation calculations. A site calibration whether completed in the field or office establishes the relationship between GNSS WGS 84 Latitude, Longitude, and ellipsoid heights to a local site northing, easting & elevation.
Course Goals & Objectives: In this module we will review the differences between grid and ground coordinate systems, datum transformation types, horizontal and vertical calibration details and scale factors. We will work with real data sets so the user can see some of the pitfalls and successes involved in a site calibration. Users will learn how to perform a site calibration using Trimble Access and Trimble Business Center. The site calibrations can be stored for later use and reports generated detailing the calibration parameters.
Prerequisites: Some of the principals and theories in this module will require some survey background. An understanding of coordinate geometry and basic geodesy will be beneficial. A good prelude to this module is course 203.
Approximate Duration: 2 hours