| Date: | 1996-04-29 18:00:00 | |
| Sender: | Andrew Sinclair <ats@ast.cam.ac.uk> | |
| Subject: | [SLR-Mail] No. 14: Survey of SLR data pre-processing | |
| Author: | Andrew Sinclair | |
| Content: | ******************************************************************************** SLR Electronic Mail 1996-04-29 18:00:00 UTC Message No. 14 ******************************************************************************** Author: Andrew Sinclair Subject: Survey of SLR data pre-processing SURVEY OF SLR DATA PRE-PROCESING BY SINGLE-PHOTON STATIONS In SLRMAIL Message No. 0008 I requested that SLR stations that operate at the single photon level should collect statistics of the distribution of their SLR data. I would be grateful if stations could now send me AVERAGE VALUES of the data that they have collected for satellite passes and calibration runs. Please send this by May 10, to give me a chance to summarise the data before the CSTG meeting in Porto (I will be away May 20 to May 31). Please send the data to ats@ast.cam.ac.uk Please keep it simple ! As an example I give below the data from RGO for February. Target N M-L M-RGO M-P SKEW KURT mm mm mm CALIB 424 17.0 +0.3 1.1 0.21 2.72 ERS-1 19 17.6 -0.3 1.3 0.15 2.71 ERS-2 25 16.9 -0.5 0.9 0.18 2.66 GFZ-1 23 16.7 -0.3 0.3 0.08 2.61 Starlette 22 19.2 -0.5 2.1 0.24 2.60 Stella 22 19.6 -0.3 1.9 0.22 2.60 Lageos 38 23.9 -0.3 5.5 0.41 2.68 Lageos-2 22 22.9 -0.5 4.6 0.39 2.65 Ajisai 22 53.2 -1.6 21.8 0.50 2.52 Topex 34 57.0 +0.9 31.0 0.58 2.65 N : number of passes or calibration runs M-L : average value of `mean minus leading-edge-half-max` M-RGO: average value of `mean minus standard RGO reference point` M-P : average value of `mean minus peak` SKEW : average value of skewness KURT : average value of kurtosis Each quantity is the average value from the N passes or calibration runs. Values of mean, peak, leading-edge-half-max, skewness and kurtosis were calculated from subroutine DISTRIB, which uses a clipping of the data at 2.5*RMS in order to determine the mean. These numbers show that the reference point used by RGO, which is determined in a somewhat complicated way, is very close to the mean calculated with an iterative 2.5*RMS rejection. If your station uses precisely a mean with iterated 2.5*RMS rejection as reference point then there is no need to give the column `M - Station`. From: ats@ast.cam.ac.uk ******************************************************************************** |