Project Title:

Codeless, Global-Position-System, Attitude-Determination System

09.01-7640B
911384
Codeless, Global-Position-System, Attitude-Determination System
Ithaco, Inc.
P.O. Box 6437
Ithaca
NY
14851-6437
Stephen J.
Fujiwaka
607-272-7640
GSFC
NAS5-31931
178

09.01-7640B
911384

Abstract:

Codeless, Global-Positioning-Satellite, Attitude-Determination System
This project will define a spaceborne attitude determination system based on Global-Positioning-Satellite
(GPS) signals. This specific innovation involves processing GPS signals without knowledge
of the digital codes required for conventional GPS receivers, making the system immune
to performance degradation resulting from the DOD policy of selective availability
and antispoofing. Precision determination of attitude (0.05 deg) and rate (0.05 deg/sec)
can be achieved at up to 10 Hz. This project addresses the need for a low-cost, low-power,
and low-mass attitude determination system for use aboard small satellite missions.
The systems engineering tasks are requirements definition for the on-board radio
system electronic design; requirements for the satellite hardware suite; attitude-determination
flight-software specifications; ground support segment definition; and planning for
a ground-based proof-of-concept demonstrator to be executed under Phase II. The expected
benefits to NASA are numerous, with the current trend toward development of small,
low-cost, multi-mission satellites. As GPS systems become a reality, they can be
expected to make traditional attitude determination systems and hardware obsolete.
As an additional benefit, this system is easily adaptable for precision orbit determination.
This attitude determination system will be marketed to prime contractors and other
private concerns that need low-cost, precision, attitude determination. The system
is also adaptable for precision orbit determination.
GPS, CGADS, attitude, satellite, systems, spacecraft