In-Reply-To: <4A2410FD.8070000@noaa.gov> To: igs-acs@igscb.jpl.nasa.gov Cc: igsstation@igscb.jpl.nasa.gov Subject: [IGSSTATION-3102]: ESOC] missing Rapid clock epochs Message-ID: From: Tim.Springer@esa.int Date: Wed, 3 Jun 2009 09:53:40 +0200 Content-Type: text/plain; charset="us-ascii" Sender: owner-igsstation Precedence: bulk ****************************************************************************** IGS Station Mail 03 Jun 09:46:12 PDT 2009 Message Number 3102 ****************************************************************************** Author: Tim Springer Dear Jim, At ESOC we construct the data we use for our Ultra-Rapids from the hourly RINEX files. We wait 20 minutes after the full hour before starting our procedure. This should be more than enough time for stations to deliver the data of the last hour. In our Ultra-Rapid processing we check the number of epochs for which we have clock epochs and this is almost always 288. However, this does not mean that for all stations the clocks are complete. Any missing clock epochs for a station will most likely be due to the fact that the station in question is "to slow" in providing the hourly RINEX data. Of course one should note here that at ESOC we do NOT generate a special rapid product. Our rapid product is the estimated part of our "00" hour Ultra-rapid submission. This is why the data submission for our rapid products is critical. We could make a seperate rapid solution that would run much later than we currently do. However, given the fact that our rapid orbits and clocks are already one of the best we consider that to be a waste of resources. Maybe the IGS station group (or infrastructure committee) could have a look into the delays of the hourly data files. I know that we have seen that at many stations the automatic procedure runs at a fixed local time meaning an increased delay when Summer/Winter time kicks in. So things can certainly be optimized. Cheers, Tim --------------------- Tim Springer Navigation Support Office, OPS-GN (nng.esoc.esa.de) European Space Operations Centre Robert Bosch Strasse 5 64293 Darmstadt Germany Tel: +49-6151-90-2029 Fax: +49-6151-90-3129 "Jim.Ray" Sent by: owner-igs-acs@igscb.jpl.nasa.gov 01/06/2009 19:33 Please respond to jim.ray@noaa.gov To cc Subject [IGS-ACS-176] missing Rapid clock epochs ****************************************************************************** IGS-ACS Mail 01 Jun 10:34:10 PDT 2009 Message Number 176 ****************************************************************************** Author: Jim Ray Recently it seems that more and more IGS Rapid clocks are missing the last hour of data each day. For 5-min samples, there should be 288 clock values per day. If the last hour is missing, then only 276 clock values will be available. The table below shows all IGR stations with <280 clock values for day 1534_0. I suspect that the reasons for the missing data are mixed. Probably, ESA and/or JPL construct their daily station RINEX files from hourly submissions and are sometimes failing to build complete daily files for their IGR processing. Please correct me if this is wrong, otherwise please consider improving your procedures to eliminate these end-of-day gaps. Since the IGS clock combination requires results from at least 2 ACs, the stations below analyzed by at least 2 ACs besides ESA or JPL probably produce daily RINEX files with the last hour missing, at least initially. Those stations are: NRCan -- CHUR, SCH2 BKG -- HOFN, WTZR GA -- MAW1 SRC -- BOR1 I do not have the time to research the data files & AC solutions of each of these stations individually, so it is possible that my interpretations are not correct. Nevertheless, it is clear that data epochs are being dropped someplace. It is very difficult for the IGS time scale to handle such recurring gaps, especially when they involve some of the best clocks in the network. So please investigate and try to eliminate these data gaps, whether in the RINEX files or in the AC analyses. Thanks, --Jim GPS week: 1534 Day: 0 MJD: 54982 | RMS (ps) OF AC CLOCK COMPARED TO COMBINATION | brd cod emr esa iga igu jpl ngs usn | NEpoch Agency -----+-------------------------------------------------------+-------------- ALGO | - - 7 7 - - - - 111 | 276 NRCan ALIC | - - - 9 - - 10 - - | 276 GA ANKR | - 15 - 7 - - - - - | 276 BKG ASPA | - 21 - 10 - - - - - | 235 NGS BOR1 | - 13 - 6 - - - - 16 | 276 SRC BRFT | - - - 15 - - 18 - - | 275 NGS CAGL | - - - 43 - - 50 - - | 152 ASI CEDU | - 15 - 7 - - - - - | 276 GA CHAT | - - - 15 - - 17 - - | 263 GNS CHUR | - 19 18 20 - - - - - | 276 NRCan CONZ | - - - 15 - - 18 - - | 276 BKG CRAO | - - - 6 - - 7 - - | 276 UNAVCO HARV | - - - 9 - - 10 - - | 276 JPL HOFN | - 67 - 32 - - - - 123 | 250 BKG KARR | - 16 - 8 - - - - - | 264 GA MAW1 | - 49 - 14 - - 20 - - | 276 GA ORID | - - - 6 - - 7 - - | 276 BKG RABT | - - - 14 - - 16 - - | 279 UNAVCO REYK | - - - 5 - - 6 - - | 275 BKG SCH2 | - - 20 21 - - - - 88 | 223 NRCan WARN | - - - 7 - - 8 - - | 276 BKG WTZR | - 21 X 10 - - - - 12 | 276 BKG -----+-------------------------------------------------------+--------------