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Ocean Hemisphere Project Superconducting Gravimeter Data **** Scheme of Read-me file for the OHP HP ***** Under the support of OHP project, an international gravity observation network is operating. This network consists of the six observation sites of Bandung in Indonesia, Canberra in Australia, Esashi and Matsushiro in Japan, Ny-Alesund in Norway and Syowa in Antarctica. At each site, the contentious gravity observation is carried out using a superconducting gravimeter (SG). In this web-page, mainly the data sampled at the 1-s interval are stored. Attached table gives some information on the station coordinates, namely, the type of SG, its scale factor, the sampling interval and others for each observation site. There is a possibility of revision of the scale factor of each SG due to newly calibration. The new calibration value will be announced on this web-page for users. The following institutes are responsible to operate the respective site; National Astronomical Observatory for Esashi, Canberra and Ny-Alesund, Kyoto University for Bandung, and National Institute for Polar Research for Syowa Station. More detailed information on the data at each site will be supplied on request to respective institutes. The names of contact persons are; Dr. Yoichi Fukuda (fukuda@kugi.kyoto-u.ac.jp) of Kyoto University, Dr. Tadahiro Sato (tsato@miz.nao.ac.jp) of National Astronomical Observatory, and Prof. Kazuo Shibuya (shibuya@nipr.ac.jp). ***************************************************** Data format(except Matsushiro): The format of the data is (9X,F10.6,A1,F9.3,A1) in Fortran style (see sample below). From left side, time (UT or JST), gravity data (voltage), remark1, pressure data (hPa) and remark2 are given. Remarks "i" and "b" denote the interpolated data and no observations respectively. SG000101 GGP1 Pressure 00:00:00 -1.549357 973.163 00:00:01 -1.549376 973.158 00:00:02 -1.549391 973.166 00:00:03 -1.549450i 973.164i 00:00:04 -1.549510 973.163 00:00:05 -1.549561 973.168 00:00:06 -1.549627 973.163 00:00:07 0.000000b 0.000b 00:00:08 -1.549742 973.161 ***************************************************** top Data format(Matsushiro): The file contains digital readings of atmospheric pressure and gravity through the GGP1 filter for every 1 second. There are two files for each day. The files are in text format. The time is UT. How to read the data long secs; /* number of seconds since either 00:00:00 or 12:00:00 */ long lpres, lgrav; /* integer data */ double pres, grav; /* float data */ FILE *fp; /* descriptor to input file */ fscanf(fp, "%4lx%5lx%7lx", &secs, &lpres, &lgrav); if (lgrav & 0x08000000) lgrav |= 0xf0000000; pres = (double) lpres / 1000.0; /* pressure in hPa */ grav = (double) lgrav / 10000000.0; /* gravity in V */ For other information, contact imanishi@ori.u-tokyo.ac.jp. ***************************************************** top Station: Bandung Station Instrument T008 Location Bandung, Indonesia Latitude (N) -6.896 Longitude (E) 107.632 Height (m) 713 StartOps 16 Dec 1997 StartRecord 19 Dec 1997 Gravity Sampling (s) 1 Recording (s) 1 Precision (mV) 0.01 Calibration(micro Gal/V) -52.23 (1micro Gal=10^-8 ms^-2) FilterCornFreq(mHz) 61.5 (GGP1 filter) NyquistCutOff (dB) 100 ( " ) PhaseShift (deg/cpd) 0.034 ( " ) Pressure Sampling (s) 1 Recording (s) 1 Precision(hPa) 0.1 Calibration 1.0 Data DataICET 97/12-00/04 Time System UT ***************************************************** top Station: Canberra Station Instrument C031 Location Mt. Stromlo, Canberra, Australia Latitude (N) -35.3206 Longitude (E) 149.0077 Height (m) 763 StartOps 27 Jan 1997 StartRecord 27 Jan 1997 Gravity Sampling (s) 1 Recording (s) 1 Precision (mV) 0.01 Calibration(micro Gal/V) -76.280 (1micro Gal=10^-8 ms^-2) FilterCornFreq(mHz) 20 (TIDE filter) NyquistCutOff (dB) - ( " ) PhaseShift (deg/cpd) 0.156 ( " ) Pressure Sampling (s) 1 Recording (s) 1 Precision (hPa) 0.1 Calibration 1.0 Data DataICET - Time System UT ***************************************************** top Station: Esashi Station Instrument T007 Location Mt. Abara, Esashi, Japan Latitude (N) 39.1511 (WGS84) Longitude (E) 141.3318 ( " ) Height (m) 434 ( " ) " 393 (above mean sea level) StartOps 2 Feb 1988 StartRecord 22 Oct 1997 < Period 1997/01/01 - 1997/10/11 > Gravity Sampling (s) 2 Recording (s) 2 Precision (mV) 0.01 Calibration(micro Gal/V) -56.334 (1micro Gal=10^-8 ms^-2) FilterCornFreq(mHz) 20 (TIDE filter) NyquistCutOff (dB) - ( " ) PhaseShift (deg/cpd) 0.156 ( " ) Pressure Sampling (s) 2 Recording (s) 2 Precision (hPa) 0.1 Calibration 1.0 Time System JST (UT+9.0 hour) < Period 1997/10/22 - after > Gravity Sampling (s) 1 Recording (s) 1 Precision (mV) 0.01 Calibration(micro Gal/V) -56.334 (1micro Gal=10^-8 ms^-2) FilterCornFreq(mHz) 61.3 (GGP1 filter) NyquistCutOff (dB) 100 ( " ) PhaseShift (deg/cpd) 0.034 ( " ) Pressure Sampling (s) 1 Recording (s) 1 Precision (hPa) 0.1 Calibration 1.0 Data DataICET 97/07-98/04 Time System UT ***************************************************** top Station: Matsushiro Station Instrument T011 Location Matsushiro Seismological Observatory Latitude (N) 36.5439 Longitude (E) 138.2032 Height (m) 451.1 StartOps 01 Dec 1995 StartRecord 06 Jan 1995 Gravity Sampling (s) 1 Recording (s) 1 Precision (mV) 0.0001 Calibration(micro Gal/V) 92.879 +/- 0.036 (1micro Gal=10^-8 ms^-2) Filter GGP1 filter Pressure Sampling (s) 1 Recording (s) 1 Precision (hPa) 0.001 Calibration 1.0 Time System UT ***************************************************** top Station: Ny-Alesund Station Instrument CO39 Location Ny-Alesund, Spitzbergen, Svalbard, Norway Latitude (N) 78.93061 Longitude (E) 11.86717 Height (m) 43 StartOps 19 Sep 1999 StartRecord 19 Sep 1999 Gravity Sampling (s) 1 Recording (s) 1 Precision (mV) 0.01 Calibration(micro Gal/V) -70.830 (temporal, 1micro Gal=10^-8 ms^-2) FilterCornFreq(mHz) 61.3 (GGP1 filter) NyquistCutOff (dB) 100 ( " ) PhaseShift (deg/cpd) 0.034 ( " ) Pressure Sampling (s) 1 Recording (s) 1 Precision (hPa) 0.1 Calibration 0.1 Data DataICET - Time System UT ***************************************************** top Station: Syowa Station Instrument T016 Location Syowa Station, Antarctic Latitude (N) -69.006735 Longitude (E) 39.585694 Height (m) 42.567 StartOps 22 Mar 1993 StartRecord 22 Mar 1993 < Period 1993/08/01 - 1999/05/31 > Sampling (s) 2 Recording (s) 2 Precision (mV) 0.01 Calibration(micro Gal/V) -57.965 (1micro Gal=10^-8 ms^-2) FilterCornFreq (mHz) 20.0 (TIDE filter) NyquistCutOff (dB) - ( " ) PhaseShift (deg/cpd) 0.156 ( " ) Pressure Sampling (s) 2 Recording (s) 2 Precision (hPa) 0.1 Calibration 1.0 Data DataICET 97/07-99/05 Time System UT < Period 1999/06/01 - after > Gravity Sampling (s) 1 Recording (s) 1 Precision (mV) 0.01 Calibration(micro Gal/V) -57.965 *(about 1.0020 ?) FilterCornFreq(mHz) 61.3 (GGP1 filter) NyquistCutOff (dB) 100 ( " ) PhaseShift (deg/cpd) 0.034 ( " ) Pressure Sampling (s) 1 Recording (s) 1 Precision (hPa) 0.1 Calibration 1.0 Time System UT |