/*-------------------------------------------------------------------- * The MB-system: mbf_mgd77dat.h 5/19/99 * $Id: mbf_mgd77dat.h 1917 2012-01-10 19:25:33Z caress $ * * Copyright (c) 1999-2012 by * David W. Caress (caress@mbari.org) * Monterey Bay Aquarium Research Institute * Moss Landing, CA 95039 * and Dale N. Chayes (dale@ldeo.columbia.edu) * Lamont-Doherty Earth Observatory * Palisades, NY 10964 * * See README file for copying and redistribution conditions. *--------------------------------------------------------------------*/ /* * mbf_mgd77dat.h defines the data structures used by MBIO functions * to store multibeam data read from the MBF_MGD77DAT format (MBIO id 21). * * Author: D. W. Caress * Date: May 19, 1999 * * $Log: mbf_mgd77dat.h,v $ * Revision 5.2 2003/04/17 21:05:23 caress * Release 5.0.beta30 * * Revision 5.1 2002/09/18 23:32:59 caress * Release 5.0.beta23 * * Revision 5.0 2000/12/01 22:48:41 caress * First cut at Version 5.0. * * Revision 4.2 2000/09/30 06:34:20 caress * Snapshot for Dale. * * Revision 4.1 1999/07/16 19:29:09 caress * First revision. * * Revision 1.1 1999/07/16 19:24:15 caress * Initial revision * * */ /* * Notes on the MBF_MGD77DAT data format: * 1. The MGD77 format is is an exchange format for marine * geophysical data (bathymetry, magnetics, and gravity). * The format standard is maintained by the National * Geophysical Data Center of NOAA. * 2. The standard MGD77 format includes a 1920 byte header * followed by 120 byte data records. The header consists * of 24 80 byte records. The first character of the first * header record is either 1 (pre-Y2K fix) or 4 (post-Y2K fix). * MB-System treats the header as 16 120 byte records and * provides no means of modifying the header. * 3. The data records are each 120 bytes long. The first * character of each data record is either * 3 (pre-Y2K fix) or 5 (post-Y2K fix). * 4. The MB-System implementation includes the support of * an arbitrary number of comment records at the beginning * of each file. The comment records are 120 bytes each * and begin with the character '#'. * */ /* header and data record in bytes */ #define MBF_MGD77DAT_HEADER_NUM 16 #define MBF_MGD77DAT_DATA_LEN 120 struct mbf_mgd77dat_struct { /* type of data record */ int kind; /* survey id */ char survey_id[8]; /* Identifier supplied by the contributing organization, else given by NGDC in a manner which represents the data. */ /* time stamp */ double time_d; int time_i[7]; int timezone; /* Corrects time (in characters 13-27) to GMT when added: equals zero when time is GMT. Timezone normally falls between -13 and +12 inclusively. */ /* navigation */ double longitude; double latitude; double heading; /* degrees */ double speed; /* km/hr */ int nav_type; /* Indicates how lat/lon was obtained: 1 = Observed fix 3 = Interpolated 9 = Unspecified */ int nav_quality; /* QUALITY CODE FOR NAVIGATION - 5 - Suspected, by the originating institution 6 - Suspected, by the data center 9 - No identifiable problem found */ /* motion sensor data */ double roll; double pitch; double heave; /* bathymetry */ int flag; /* MB-System style beamflag */ double tt; /* two way travel time in sec */ double bath; /* corrected depth in m */ int bath_corr; /* BATHYMETRIC CORRECTION CODE This code details the procedure used for determining the sound velocity correction to depth: 01-55 Matthews' Zones with zone 59 Matthews' Zones, no zone 60 S. Kuwahara Formula 61 Wilson Formula 62 Del Grosso Formula 63 Carter's Tables 88 Other (see Add. Doc.) 99 Unspecified */ int bath_type; /* BATHYMETRIC TYPE CODE Indicates how the data record's bathymetric value was obtained: 1 = Observed 3 = Interpolated 9 = Unspecified */ /* magnetics */ double mag_tot_1; /* MAGNETICS TOTAL FIELD, 1ST SENSOR In tenths of nanoteslas (gammas). For leading sensor. Use this field for single sensor. */ double mag_tot_2; /* MAGNETICS TOTAL FIELD, 2ND SENSOR In tenths of nanoteslas (gammas). For trailing sensor. */ double mag_res; /* MAGNETICS RESIDUAL FIELD In tenths of nanoteslas (gammas). */ int mag_res_sensor; /* SENSOR FOR RESIDUAL FIELD 1 = 1st or leading sensor 2 = 2nd or trailing sensor 9 = Unspecified */ double mag_diurnal; /* MAGNETICS DIURNAL CORRECTION - In tenths of nanoteslas (gammas). (In nanoteslas) if 9-filled (i.e., set to "+9999"), total and residual fields are assumed to be uncorrected; if used, total and residuals are assumed to have been already corrected. */ double mag_altitude; /* DEPTH OR ALTITUDE OF MAGNETICS SENSOR In meters. + = Below sealevel - = Above sealevel */ /* gravity */ double gravity; /* OBSERVED GRAVITY In milligals. Corrected for Eotvos, drift, and tares */ double eotvos; /* EOTVOS CORRECTION In milligals. E = 7.5 V cos phi sin alpha + 0.0042 V*V */ double free_air; /* FREE-AIR ANOMALY In milligals. Free-air Anomaly = G(observed) - G(theoretical) */ /* seismic */ int seismic_line; /* SEISMIC LINE NUMBER Used for cross referencing with seismic data. */ int seismic_shot; /* SEISMIC SHOT-POINT NUMBER */ /* comment */ char comment[MBF_MGD77DAT_DATA_LEN]; };