Ephemeris/attitude reference determination using on-board optics and other satellite ephemeris

A space vehicle ephemeris determination system comprising:

• a processor;
• a memory coupled to said processor, said memory storing ephemeris determination instructions that determine ephemeris using optical payload pointing data and reference spacecraft ephemeris data;
• an optical payload assembly coupled to said processor for pointing to at least one reference spacecraft and providing said optical payload pointing data to said processor;
• and
• a receiver coupled to said processor which receives as input ephemeris information for at least one reference spacecraft and outputs said reference spacecraft ephemeris data to said processor.

A method for determining attitude for a space vehicle, the method comprising:

• pointing an optical payload sensor to at least one reference spacecraft;
• obtaining pointing direction information for said optical payload sensor;
• obtaining reference ephemeris information for said reference spacecraft;
• and
• determining attitude for said space vehicle based on said pointing direction information and said reference ephemeris information.

A space vehicle attitude determination system comprising:

• a processor;
• a memory coupled to said processor, said memory storing attitude determination instructions that determine ephemeris using optical payload pointing data and reference spacecraft ephemeris data;
• an optical payload assembly coupled to said processor for pointing to at least one reference spacecraft and providing said optical payload pointing data to said processor;
• and
• a receiver coupled to said processor which receives as input ephemeris information for at least one reference spacecraft and outputs said reference spacecraft ephemeris data to said processor.