Date: Wed, 18 Sep 2002 13:52:33 +0200 (CEST) From: Gerd Gendt To: IGSmail Subject: [IGSMAIL-4085]: Ultra-Rapid tropospheric products available Message-ID: Sender: owner-igsmail Precedence: bulk ****************************************************************************** IGS Electronic Mail 18 Sep 04:59:02 PDT 2002 Message Number 4085 ****************************************************************************** Author: Gerd Gendt Dear colleagues, In December 2000 the IGS Governing Board decided to explore the use of its global hourly network for generation of Ultra-Rapid tropospheric products. It was started a Pilot Experiment to establish all the software components and to assess the quality of the product, which was planned to be generated every three hours at the beginning. After some preparations, since summer 2001 Ultra-Rapid tropospheric products are generated every three hours. It is a combination of submissions from 7 Analysis Centers (ACs). Each product contains the Zenith Path Delay (ZPD) values for the last 12 hours and has a sampling rate of 1 hour. The product submissions of the ACs have a delay from 0 to 2.5 hours, in average 1.5 hours. Presently, the combination starts if all centers have contributed. If more frequent and/or faster products are needed by the user community then IGS will try to change the schedule accordingly. The quality of the product was assessed during the Pilot Experiment and is (compared to IGS Final Tropospheric Product) 5 to 6 mm ZPD for the standard deviation and -1 to 1 mm ZPD for the bias. The internal consistency between the ACs (comparisons to hourly combination itself) is checked each time and amount to 3 to 5 mm ZPD for the standard deviation and -4 to 4 mm ZPD for the bias. The bias-scatter from site to site is 3 to 6 mm ZPD. The product includes ~100 sites, where ~50 are contributed by two or more ACs. The ftp-address and some information on products and statistics are summarized in the appendix. Any comments, remarks on this new product are very much appreciated. Best regards Gerd Gendt ------------------------------------------------------------------------- Appendix: Address for Ultra-Rapid tropospheric Products: ftp.gfz-potsdam.de/pub/transfer/kg_igs/nrtigstrop/prod Files: 1. igs60_wwwwd_hh.tro (e.g.igs60_11840_02.tro ): Product file in the SINEX-TRO-format, containing the solutions from all submitted sites for the last 12 hours with a sampling rate of 60 minutes. 2. TROPSUM_wwwwd.ovw (e.g. TROPSUM_11840.ovw): Contains for each hour a block with statistics on the comparison of the Individuals ACs to the combined product, e.g. Summary for 11840_23 11840_23 +Center: EMR ESA GFZ 11840_23 . | bias sdev nv d| bias sdev nv d| bias sdev nv d|... 11840_23 .---------------------------------------------------------... 11840_23 .Mean | 1.0 2.0 | -2.9 4.9 | 1.1 2.2 |... 11840_23 .Stddev | 3.1 | 4.9 | 3.2 |... 11840_23 .#Delete | 1 1 | 1 1 | 1 . |... 11840_23 .#Sites | 22 22 | 26 26 | 28 29 |... 11840_23 Number of sites: 38 20 48 106 (>3AC 2AC 1AC sum) ... 3. TROP_wwwwd_hh.sum (e.g. TROP_11840_02.sum): Summary report of each hourly combination in the format used for the final combination (contains also information for each station). ------------------------------------------------------------------------- ****************************************************************************** * Gerd Gendt Phone : ++49 331 288 1114 * * _/_/_/ _/_/_/_/_/_/ GeoForschungsZentrum Fax : ++49 331 288 1111 * * _/ _/ _/ Aufgabenbereich 1 E-Mail: gendt@gfz-potsdam.de * * _/ _/_/ _/_/ _/ Telegrafenberg A17 * * _/ _/ _/ _/ D-14473 Potsdam , GERMANY * * _/_/_/ _/ _/_/_/ AFTP: //ftp.gfz-potsdam.de/pub/igsprod * * www : //op.gfz-potsdam.de/S11/index_S11.html * ******************************************************************************