13th International Laser Ranging Workshop | Automation and Control Systems Abstracts

Title	Primary Author
SLR2000: Closed Loop Tracking with a Photon-Counting Quadrant Detector	Jan McGarry
NASA GSFC Code 920.3 Greenbelt, Maryland USA Voice: 301-614-5867 Fax: 301-614-5970 Email: Jan.McGarry@gsfc.nasa.gov Thomas Zagwodzki John Degnan NASA GSFC Code 920.3 Greenbelt, Maryland USA SLR2000 will close the tracking loop using a Photek four quadrant Micro-Channel Plate (QMCP) detector which will provide information to correct the along-track, ranging, and cross-track errors automatically in real time. Analysis and simulation results showing the expected performance of this loop will be presented and will take into account the recent test results of the Xybion mount's tracking abilities. The details of the full tracking loop (both uplink and downlink) will also be given. Oral paper; received August 16, 2002

Improvements in the Automation of the Zimmerwald SLR Station	Werner Gurtner
Astronomical Institute, University of Bern Sidlerstrasse 5 CH-3012 Bern Switzerland Voice: 0041 31 6318591 Fax: 0041 31 6313869 Email: werner.gurtner@aiub.unibe.ch E. Pop, J. Utzinger The paper summarizes the components essential for automated or remotely controlled operation of the Zimmerwald Laser station and describes in more details new components and recently performed improvements. Oral paper; received August 16, 2002

Infrared Sky Camera -- The Production Model	Anthony Mallama
Raytheon 4400 Forbes Blvd. Lanham, MD 20715 USA Voice: 301-794-5443 Fax: 301-794-7106 Email: anthony_mallama@raytheon.com John J. Degnan NASA Goddard Space Flight Center Frederick E. Cross, Judith M. Mackenzie Raytheon A thermal infrared imager for mapping the changing cloud cover over a tracking station has been developed. The instrument produces qualitative results (clear, hazy and cloudy) that have been compared with visual estimations, and the two are found to be in good agreement. There have been no instances of gross disagreements where one source judged the sky to be clear and the other assessed it cloudy, though there were moderate disagreements (clear versus hazy, or hazy versus cloudy) approximately one-third of the time. Following two years of development and testing, a production model has been manufactured which can be shipped to any location, assembled easily and put into operation quickly. This presentation gives an overview of the instrument, explains how it works, and shows sample results. Oral paper; received August 19, 2002

Automated operational software at Shanghai SLR station	Zhongping Zhang
Shanghai Observatory 80 Nandan Road Shanghai 200030 CHINA Voice: 86-21-64386191 Fax: 86-21-64384618 Email: yangfm@center.shao.ac.cn Yang Fumin Shanghai Observatory 80 Nandan Road Shanghai 200030 CHINA Georg Kirchner, Franz Koidl Institute for Space Reserch/Austrian Academy of Sciences Observatory Lustbuhel A-8042 Graz AUSTRIA A real-time operational software interface under Windows95 system at Shanghai station was reported in the 11th International Workshop on Laser Ranging in 1998 in Deggendorf, Germany. For the need of ranging automation and daylight tracking, we developed an automated operational software, based on above software system. This paper describes the feature of the software: Automated Sun avoidance Real-time correction of orbit prediction Return identification and range gate automated setting Automated system diagnosis The software has been used in Shanghai SLR station and partly used in Graz. Oral paper; received August 22, 2002

Berne/Herstmonceux Timebias Service	Roger Wood
NERC Space Geodesy Facility Herstmonceux Castle Hailsham, East Sussex, BN27 1RN UNITED KINGDOM Voice: +44 1323 833888 Fax: +44 1323 833929 Email: Roger.Wood@nerc.ac.uk Werner Gurtner Astronomical Institute of Berne SWITZERLAND Individual timebias corrections for all ILRS satellites are calculated at Herstmonceux every 15 minutes from normal point data deposited hourly at CDDIS. They are available to the global network in near real time, on demand, from a dedicated timebias server in Berne. Oral paper; received August 23, 2002

Sun Avoidance Software	Zhongping Zhang
Shanghai Observatory, Academia Sinica 80 Nandan Road Shanghai 200030 CHINA Voice: 86-21-64386191 Fax: 86-21-64384618 Email: zzp@center.shao.ac.cn Yang Fumin Shanghai Observatory, Academia Sinica 80 Nandan Roa Shanghai 200030 CHINA Georg Kirchner, Franz Koidl Institute for Space Research, Austrian Academy of Sciences Observatory Lustbuhel A-8042 Graz AUSTRIA In daylight tracking, it is very important to take effective measures to avoid strong light from the Sun. This paper presents two methods adopted at Shanghai and Graz, with which the specified path can be designed by software and the telescope will move safely around the Sun with a limited angle. Poster paper; received September 04, 2002

Intelligent Scheduler, Prioritize in the Fly	Christopher Clarke
Honeywell Technical Solutions Inc. 7515 Mission Drive Lanham, MD 20706 USA Voice: 301-805-3068 Fax: 301-805-3974 Email: christopher.clarke@honeywell-tsi.com Julie Horvath Honeywell Technical Solutions Inc. 7515 Mission Drive Lanham, MD 20706 USA Honeywell Technology Solutions Inc. (HTSI) is developing a new mission planning and scheduling software package for NASA. This new, Intelligent Scheduler, which is based on the HTSI developed scheduler used by the Matera Laser Ranging Observatory (MLRO), will improve on the current NASA SATCOP Mission Scheduling software by allowing the dynamic prioritizing of satellites. The current scheduling scenario assigns static priorities to satellites and schedules the satellites according to those priorities. The new scheduler will allow the priority of a satellite to change according to criteria, such as, a satellite's position and the amount of data recently tracked. Additional features will be included, such as, fine interleaving and sun zone avoidance. The tracking schedule will alternate between a selected satellite and lower priority satellites at given time intervals when using fine interleaving. The Intelligent Scheduler will be a useful tool for generating optimal tracking strategies for the increasing number and variety of satellite missions. This paper will provide an overview of the Intelligent Scheduler and demonstrate its capabilities. Oral paper; received September 04, 2002

Incorporation of GPS Data into HTSI Prediction Cycle to Support the ICESat Mission	Julie Horvath
Honeywell Technology Solutions Inc. 7515 Mission Dr Lanham, MD 20706 USA Voice: (301)805-3951 Fax: (301)805-3974 Email: julie.horvath@honeywell-tsi.com Mark Davis Honeywell Technology Solutions Inc. 7515 Mission Dr Lanham, MD 20706 USA Peter Shelus, Randy Ricklefs, SungPil Yoon University of Texas at Austin, Center for Space Research 3925 W. Braker Lane, Suite 200 Austin, TX 78712-1083 USA Since the GFZ mission ended in 1999, the ILRS has recognized the necessity to incorporate supplemental satellite position data into the prediction generation process for very low Earth orbiting satellites. The combination of very low satellite altitude and a poor SLR station geometry combines to provide a weak acquisition data product, consequently making tracking more difficult. Current missions, such as CHAMP and GRACE, utilize on-board GPS receivers that provide precise positions to create SLR predictions. The upcoming Ice Cloud and Land Elevation Satellite (ICESat) will be launched into a 600 km orbit in December 2002. Although IceSat will fly at a higher altitude than CHAMP or GRACE, supplemental data will be required to ensure smooth acquisition by the ILRS stations to support the POD requirements for the mission. HTSI and the University of Texas have developed a process to incorporate the ICESat GPS data, provided by the two on-board BlackJack GPS receivers, into the automated sub-daily SLR acquisition data and delivery process. This poster will describe the mission goals of ICESat and illustrate the efforts of both HTSI and the University of Texas in the generation and distribution of the GPS enhanced, highly accurate acquisition data. Poster paper; received September 09, 2002