| Date: | 1996-12-19 16:00:00 | |
| Sender: | Werner Gurtner <[Mailed Werner Gurtner <GURTNER@aiub.unibe.ch>]> | |
| Subject: | [SLR-Mail] No. 38: New SLR System in Zimmerwald | |
| Author: | Werner Gurtner | |
| Content: | ******************************************************************************** SLR Electronic Mail 1996-12-19 16:00:00 UTC Message No. 38 ******************************************************************************** Author: Werner Gurtner Subject: New SLR System in Zimmerwald ZIMLAT: The New SLR Telescope in Zimmerwald ------------------------------------------- Recently we have started to range to satellites with our new telescope in Zimmerwald in an experimental mode (single frequency only). The first quick look file with observations to low-orbiting satellites up to Lageos has been submitted to EDC on December 18, 1996 with data of the previous night. We are still having problems in the following areas, both of which are due to the special design of the telescope: - The beam quality in the far field is not yet sufficient. We still don´t have an axicon of sufficient quality to transform the laser beam into the desired ring shape. Ranging to Lageos is just possible, but not yet with sufficient yield. - The in-pass calibration also gives us some problems due to substantial backscatter in the instrument. The fast switching from one satellite to the next works pretty well. Reacquisition of the latter can be done within about 15-30 seconds after having left the former satellite. May I ask the SLR Analysis Centers to carefully check the data and to treat them with the necessary caution. Local Site Ties --------------- Monument CDP DOMEX Components Accuracy Date Inscription Number Number dX dY dZ mm yy-mm-dd Laser (Old laser) 7810.48.01 14001S001 -13.680 -6.012 6.242 1 90-01-25 Laser (ZIMLAT) 7810.68.01 140010S07 -13.506 -5.986 6.420 1 96-05-01 (Geocentric differential coordinates from the GPS monument (DOMES 14001M004) to the SLR telescope´s intersection of axes.) The old laser system (14001S001) was removed end of April 1995. The new telescope is within a few millimeters in the same place, its horizontal axis is about 25 cm higher. ZIMLAT minus old system +0.174 +0.026 +0.178 Observables: ----------- Currently we are working with a Hamamatsu PM, wavelength 423 nm (Titanium Sapphire), Stanford Counter, single to multiphoton range, time walk in function of received signal strength corrected, observation rate 10 hertz. Next Plans: ----------- - Twilight and daylight observations to LEOs - Improvement of the in-pass calibration - Tests with improved axicon --> Increase range - SPAD receiver tests Werner Gurtner Zimmerwald Satellite Observatory [Mailed From: Werner Gurtner ******************************************************************************** |