Citation
Abstract
This article describes an asynchronous system to estimate the range between a spacecraft and a ground station from an optical or RF uplink, and an optical downlink. It is built as an improvement over Optical Telemetry Ranging, a method described in a previous article, which adapted the basic principles of RF Telemetry Ranging to optical links and standards. The fundamental principle of an asynchronous ranging system is that range measurements should be recovered without needing to synchronize the uplink receiver and the downlink transmitter on board the spacecraft (hence the name asynchronous). To do so, the observables required for the range computation are obtained at the ground station’s uplink subsystem and at the spacecraft’s uplink receiver, instead of the ground station’s uplink and downlink subsystems. The measurement obtained on board the spacecraft is then sent back to Earth, as part of telemetry, where it is time-tagged and post-processed for range recovery purposes. The article is divided into two parts. First, it provides an overview of an asynchronous ranging system with specific emphasis on the proposed modifications to the previous Optical Telemetry Ranging. Then, it describes a software prototype developed at the Jet Propulsion Laboratory to validate its operation under representative channel conditions expected for the Deep Space Optical Communications terminal on board the Psyche spacecraft.
Keywords
Details
- Volume
- 42-232
- Published
- February 15, 2023
- Pages
- 1–18
- File Size
- 496.8 KB