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Moving to kHz Ranging. kHz Experiences in Graz SLR 2000 Status & Issues Herstmonceux kHz Status Complete PC Board for kHz SLR Others ? Discussion, Questions, Plans …. Eastbourne , October 200 5. kHz Ranging : Graz Experiences. 2 Years Experience with the Graz kHz SLR System.
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Moving to kHz Ranging • kHz Experiences in Graz • SLR 2000 Status & Issues • Herstmonceux kHz Status • Complete PC Board for kHz SLR • Others ? • Discussion, Questions, Plans … Eastbourne, October 2005
kHz Ranging: Graz Experiences • 2 Years Experience • with the • Graz kHz SLR System Eastbourne, October 2005
2 years kHz Ranging: • Fully operational since 2 years, day and night; • All satellites - from Champ to GPS 35 / 36 – are tracked; • Routinely 2000 Hz used (lower repetition rates would be possible, but are never used ...); • Laser System is running very stable; • Pump Diodes: Now 6000 hours, still perfect ... • Results: NOT ONLY (big) increase in return numbers; • EVERYTHING has improved significantly: • Stability; Single Shot RMS; Accuracy; • Additional Outputs Results … Eastbourne, October 2005
2 years kHz Ranging Experiences in Graz (1): • kHz SLR gives lot of returns (million !) – even with J lasers ! • kHz lasers are DPSS (Diode Pumped Solid State) units: • (... like changing from tubes to transistors ) • They deliver very stable, very uniform pulses; • They can deliver short pulses (10 ps in Graz); • This results in 2-3 mm SS RMS: • For CAL AND for – some – satellites (Grace, Champ..) Eastbourne, October 2005
kHz Ranging: Grace SS RMS 10 Hz Laser kHz Laser
2 years kHz Ranging Experiences in Graz (2): • With kHz, you get not only more and better returns,but also additional information: • You can „see“ single Retro-Reflectors; • With up to 100 k pts/NP: Single-NP-statistics ??? • You can „see“ satellite spin and measure its parameters ! Eastbourne, October 2005
Ajisai Spin Determination • AJISAI: Retro panels seen at variable distances; • AJISAI rotates (0.51 Hz); • @ 10 Hz: Big Sat Signature; @ kHz: Single Retro Motion visible Eastbourne, October 2005
kHz Ranging: AJISAI Spin • AJI26907 • Daylight • 300 k pts Eastbourne, October 2005
Ajisai Spin Determination • AJISAI • 10 secs offull pass: • 11 k rets Eastbourne, October 2005
Ajisai Spin Determination AJISAI: 2.5 secs of full pass; 3 k rets; Spin: 0.51 Hz Eastbourne, October 2005
kHz Valibrations: Single Shot RMS 10 Hz 2 kHz
kHz Ranging: Graz Experiences • High Orbit Satellites, e.g. GPS 35 / GPS 36: • Difficult to track for most SLR stations; • Low return quotes; • Not many stations get daylight GPS returns … • kHz: Also advantages for GPS 35 / 36 Tracking: • Acquisition is faster, easier with kHz laser; • More returns / NP from GPS than with 10 Hz lasers; • Day and night: Very similar results; Eastbourne, October 2005
kHz Ranging: GPS 35/36 • GPS-35: • - Daylight Pass; • - 12 k pts remaining; • - Down to 47° Elev. • - 4.5 mm RMS
kHz Ranging: Graz Experiences • Additional Information / all presentations of the kHz Workshop 2004 in Graz available at: http://khzslr.oeaw.ac.at/presentations.htm Eastbourne, October 2005
kHz Ranging: Graz Experiences Conclusion: The kHz Poem .... Kilo-Hertz is lot of fun ! At least if all the work is done It DOES make sense – you should NOT wait … You should increaseyour firing rate !!! Eastbourne, October 2005