Cheers:
This (below) from Sheldon Meshulam today (regarding my musings over the
use of GPS as an artificial horizin source):
.......................................................................
*hello,
I remembered reading about this but could not find the reference until
now.
Doesn't look too practical at this point
Here is the link,
http://einstein.stanford.edu/gps/ABS/att_for_aircraft_rch1998.html
cya Sheldon
GPS-Based Attitude for Aircraft
Roger C. Hayward, Demoz Gebre-Egziabher, J. David Powell
Department of Aeronautics and Astronautics, Stanford University
Presented May 1998 at International Conference on Integrated
Navigation Systems in St. Petersburg Russia
ABSTRACT
GPS was used with ultra-short baselines (2-3 carrier wavelengths) in a
triple antenna configuration to obtain aircraft atti-tude in real time.
Through algorithm selection and error source calibration,
accuracies of 0.1, 0.15 and 0.2 rms were obtained for pitch roll and
yaw respectively. The accuracy and robustness of the system was enhanced
by combining the ultra short-baseline GPS attitude solution with an
attitude solution derived using inertial sensors. Both inexpensive
automotive grade rate gyros and tactical grade inertial sensors were
tested. The solid state auto grade gyros allow coasting through
tem-porary GPS outages lasting 2 minutes with attitude errors less than
6
degrees. The tactical grade inertial sensors use the GPS primarily for
initial alignment and are able to coast for up to 30 minutes durring
AGPS outage. The combined GPS-inertial system has a 20Hz output
sufficient to drive glass cockpit type displays. A prototype system was
built and flight tested in a Beechcraft Queen Air. The system installed
and flight tested in the Queen Air compares favorably to the performance
of the existing vacuum driven instruments. It is currently being used in
ongoing research at Stanford with futuristic high resolution
displays[1].
A Version of this Entire Paper is Available (0.1 Mb)
Return to Publications List of the Stanford University GPS Lab
Roger C. Hayward (1st Author) skylar@stanford.edu
.......................................................................
I feel better now, thank you, Sheldon....
Happy Landings
Ferg #A064
|