Engineering topics

Schwartz, Jon A.

Publications and source records attributed to Schwartz, Jon A..

4 records

NASA NTRS1990

Laser ranging error budget for the Topex/Poseidon satellite

A laser ranging error budget is detailed, and a specific error budget is derived for the Topex/Poseidon satellite. A ranging uncertainty of 0.76 cm is predicted for Topex/Poseidon at 20 deg elevation using the presently designed laser retroreflector array and only modest improvements in present system operations. Atmospheric refraction and satellite attitude effects cause the predicted range error to vary with satellite elevation angle from 0.71 cm at zenith to 0.76 cm at 20 deg elevation. This a priori error budget compares well with the about 1.2-cm rms a posteriori polynomial orbital fit using existing data taken for an extant satellite of similar size and orbit.

Schwartz, Jon A.↗

NASA NTRS1990

Pulse spreading and range correction analysis for satellite laser ranging

The pulse spreading resulting from light detection and ranging measurements of the range to earth-orbiting satellites is described. An analysis quantifying this pulse spreading and the calculation of corrections to be applied to the lidar range determination of satellites is detailed.

Schwartz, Jon A.↗

NASA NTRS1988

Space Station-based deep-space optical communication experiments

A series of three experiments proposed for advanced optical deep-space communications is described. These proposed experiments would be carried out aboard the Space Station to test and evaluate the capability of optical instruments to conduct data communication and spacecraft navigation for deep-space missions. Techniques for effective data communication, precision spacecraft ranging, and accurate angular measurements will be developed and evaluated in a spaceborne environment.

Chen, Chien-Chung↗

NASA NTRS1988

Studies of laser ranging to the TOPEX satellite

A collaborative effort of NASA and CNES will lead to the launching of the 'TOPEX' ocean topography experiment satellite in the early 1990s; the satellite will employ two onboard altimeters whose calibration may be accomplished by a worldwide lidar tracking network that is projected to enter into operation in the 1990s. Attention is presently given to a computer model of the use of different ground-based lidar systems, in conjunction with retroreflector array designs, for TOPEX satellite calibration.

Schwartz, Jon A.↗