ashtech DG14, Reference Manual

Page: 61 / 390

Basic Operation 41
Basic Operation
On initial power-up, or after issuing the $PASHS,INI command (initialize memory)
or $PASHS,RST command (restore defaults), the antenna altitude is set to zero.
The Point Positioning option improves the accuracy of a stand-alone absolute
position of a stationary receiver from about 5 meters to less than one meter over a
period of four hours, and can typically get down to the couple of meters level after
ten hours. Point positioning uses an averaging technique to reduce the effects of
Selective Availability (SA) and other fluctuating errors. You can set the Point
Positioning mode with the $PASHS,PPO command See the “PPO: Point
Positioning” section on page 143 for more details on this command. The Point
Positioning option [T] must be set in the receiver for this command to work.
The DG16 uses the Ohio State University 91A geoid model (OSU91A). For more
information on OSU91A, refer to the Ohio State University:
Rapp, R.H., Y.M. Wang and N.K. Pavlis, 1991: The Ohio State 1991
Geopotential and Sea Surface Topography Harmonic Coefficient Models,
Report No. 410. Columbus: Department of Geodetic Science and
Surveying, The Ohio State University.
The Ohio State University
Department of Civil and Environmental Engineering and Geodetic Science
470 Hitchcock Hall
2070 Neil Avenue
Columbus, OH 43210 USA
Tel: 614-292-2771
Fax: 614-292-3780
Web: http://www-ceg.eng.ohio-state.edu
DEFAULT SETTINGS
$PASHS,FIX
—
Fixed Altitude Mode (0)