Automation and Control Systems Session Summary

J. McGarry and W. Gurtner

More and more SLR systems are implementing some features of automation and remote control. New systems especially are being built with these capabilities. Two examples of remote control and automation were shown at this session. The first was an impressive demonstration of the Zimmerwald capabilities by Werner Gurtner. Werner connected to the station via the internet and did a real-time demonstration of ranging to the Jason satellite. A camera mounted to the system showed a live display of where the telescope was pointing, and the system status was shown, each updating in real-time. After checking the "Eurostat" display of what other stations were tracking, Werner switched targets to pick up a Topex pass. Many features of the remote control and display capability were shown including the ability to do some simple control via cell phone.

Takashi Uchimura showed the remote control operation of the GUTS SLR system which is operated by remote control via dedicated communications lines from the Tsukuba Space Center (TKSC). The station provides camera displays back to the TKSC as well as system status information. Some automation has also been implemented, including sun avoidance, aircraft protection via radar, and automated laser turn off in case of system problems or dropped communications with TKSC.

On a slightly different topic from the above two talks, John Degnan presented the mathematical analysis required to completely define the effects of the telescope and transceiver optics on the SLR2000 laser transmit and receive pulses. This information is needed to automate the satellite tracking and allow the software to (i) control the point-ahead optics for the transmit beam, and (ii) correctly rotate and make use of the receive image for closed loop bias calculations.

Randy Ricklefs presented the new Consolidated Laser Ranging Prediction Format (CPF) which provides a single format for SLR, LLR and transponder predictions. For SLR this new format eliminates the need for on-site gravity models and tuned IRVs by providing vectors spaced at approximately one minute intervals. The interval between vectors is changeable and can be made much larger for LLR and transponders. The format provides for separate transmit and receive vectors which provides the point-ahead and point-behind information needed for transponder tracking as well as for SLR2000 use. Testing for SLR and LLR has begun at MLRS. NSGF will soon provide predictions in this new format. It is hoped that the CPF will become the standard for all ILRS stations in the near future.