driver_rtcm3.c

/*****************************************************************************

This is a decoder for RTCM-104 3.x, a serial protocol used for
broadcasting pseudorange corrections from differential-GPS reference
stations.  The applicable specification is RTCM 10403.1: RTCM Paper
177-2006-SC104-STD.  This obsolesces the earlier RTCM-104 2.x
specifications. The specification document is proprietary; ordering
instructions are accessible from <http://www.rtcm.org/>
under "Publications".

Unike the RTCM 2.x protocol, RTCM3.x does not use the strange
sliding-bit-window IS-GPS-200 protocol as a transport layer, but is a
self-contained byte-oriented packet protocol.  Packet recognition is
handled in the GPSD packet-getter state machine; this code is
concerned with unpacking the packets into well-behaved C structures,
coping with odd field lengths and fields that may overlap byte
boudaries.  These report structures live in gps.h.

Note that the unpacking this module does is probably useful only for
RTCM reporting and diagnostic tools.  It is not necessary when
passing RTCM corrections to a GPS, which normally should just be
passed an entire correction packet for processing by their internal
firmware.

Decodes of the following types have been verified: 1004, 1005, 1006,
1008, 1012, 1013, 1029. There is good reason to believe the 1007 code
is correct, as it's identical to 1008 up to where it ends.

The 1033 decode was arrived at by looking at an rtcminspect dump and noting
that it carries an information superset of the 1008.  There are additional
Receiver and Firmware fields we're not certain to decode without access
to an RTCM3 standard at revision 4 or later, but the guess in the code
has been observed to correctly analyze a message with a nonempty Receiver
field.

This file is Copyright (c) 2010-2018 by the GPSD project
SPDX-License-Identifier: BSD-2-clause

*****************************************************************************/

#include <string.h>

#include "gpsd.h"
#include "bits.h"

#ifdef RTCM104V3_ENABLE

/* scaling constants for RTCM3 real number types */
#define GPS_PSEUDORANGE_RESOLUTION	0.02	/* DF011 */
#define PSEUDORANGE_DIFF_RESOLUTION	0.0005	/* DF012,DF042 */
#define CARRIER_NOISE_RATIO_UNITS	0.25	/* DF015, DF045, DF50 */
#define ANTENNA_POSITION_RESOLUTION	0.0001	/* DF025-027 */
#define GLONASS_PSEUDORANGE_RESOLUTION	0.02	/* DF041 */
#define ANTENNA_DEGREE_RESOLUTION	25e-6	/* DF062 */
#define GPS_EPOCH_TIME_RESOLUTION	0.1	/* DF065 */
#define PHASE_CORRECTION_RESOLUTION	0.5	/* DF069-070 */


/* Other magic values */
#define GPS_INVALID_PSEUDORANGE		0x80000	/* DF012, DF018 */
#define GLONASS_INVALID_RANGEINCR	0x2000	/* DF047 */
#define GLONASS_CHANNEL_BASE		7	/* DF040 */

/* Large case statements make GNU indent very confused */
/* *INDENT-OFF* */

/* good source on message types:
 * https://software.rtcm-ntrip.org/export/HEAD/ntrip/trunk/BNC/src/bnchelp.html
 * Also look in the BNC source
 * and look at the tklib source: http://www.rtklib.com/
 */
void rtcm3_unpack(const struct gps_context_t *context,
		  struct rtcm3_t *rtcm, char *buf)
/* break out the raw bits into the scaled report-structure fields */
{
    unsigned int n, n2, n3, n4;
    int bitcount = 0;
    unsigned int i;
    signed long temp;
    bool unknown = true;;

#define ugrab(width)	(bitcount += width, ubits((unsigned char *)buf, bitcount-width, width, false))
#define sgrab(width)	(bitcount += width, sbits((signed char *)buf, bitcount-width, width, false))
#define GPS_PSEUDORANGE(fld, len) \
    {temp = (unsigned long)ugrab(len);		\
    if (temp == GPS_INVALID_PSEUDORANGE)	\
	fld.pseudorange = 0;			\
    else					\
	fld.pseudorange = temp * GPS_PSEUDORANGE_RESOLUTION;}
#define RANGEDIFF(fld, len) \
    temp = (long)sgrab(len);			\
    if (temp == GPS_INVALID_PSEUDORANGE)	\
	fld.rangediff = 0;			\
    else					\
	fld.rangediff = temp * PSEUDORANGE_DIFF_RESOLUTION;

    memset(rtcm, 0, sizeof(struct rtcm3_t));
    //assert(ugrab(8) == 0xD3);
    //assert(ugrab(6) == 0x00);
    ugrab(14);

    rtcm->length = (unsigned int)ugrab(10);
    rtcm->type = (unsigned int)ugrab(12);

    gpsd_log(&context->errout, LOG_RAW, "RTCM3: type %d payload length %d\n",
	     rtcm->type, rtcm->length);

    switch (rtcm->type) {
    case 63:
        /* RTCM - 63
         * BDS/BeiDou Ephemeris
         * length 64
	 */
	break;

    case 1001:
	/* GPS Basic RTK, L1 Only */
	rtcm->rtcmtypes.rtcm3_1001.header.station_id = (unsigned int)ugrab(12);
	rtcm->rtcmtypes.rtcm3_1001.header.tow = (time_t)ugrab(30);
	rtcm->rtcmtypes.rtcm3_1001.header.sync = (bool)ugrab(1);
	rtcm->rtcmtypes.rtcm3_1001.header.satcount = (unsigned short)ugrab(5);
	rtcm->rtcmtypes.rtcm3_1001.header.smoothing = (bool)ugrab(1);
	rtcm->rtcmtypes.rtcm3_1001.header.interval = (unsigned short)ugrab(3);
#define R1001 rtcm->rtcmtypes.rtcm3_1001.rtk_data[i]
	for (i = 0; i < rtcm->rtcmtypes.rtcm3_1001.header.satcount; i++) {
	    R1001.ident = (unsigned short)ugrab(6);
	    R1001.L1.indicator = (unsigned char)ugrab(1);
	    GPS_PSEUDORANGE(R1001.L1, 24);
	    RANGEDIFF(R1001.L1, 20);
	    R1001.L1.locktime =	(unsigned char)sgrab(7);
	}
#undef R1001
	unknown = false;
	break;

    case 1002:
	/* GPS Extended RTK, L1 Only */
	rtcm->rtcmtypes.rtcm3_1002.header.station_id = (unsigned int)ugrab(12);
	rtcm->rtcmtypes.rtcm3_1002.header.tow = (time_t)ugrab(30);
	rtcm->rtcmtypes.rtcm3_1002.header.sync = (bool)ugrab(1);
	rtcm->rtcmtypes.rtcm3_1002.header.satcount = (unsigned short)ugrab(5);
	rtcm->rtcmtypes.rtcm3_1002.header.smoothing = (bool)ugrab(1);
	rtcm->rtcmtypes.rtcm3_1002.header.interval = (unsigned short)ugrab(3);
#define R1002 rtcm->rtcmtypes.rtcm3_1002.rtk_data[i]
	for (i = 0; i < rtcm->rtcmtypes.rtcm3_1002.header.satcount; i++) {
	    R1002.ident = (unsigned short)ugrab(6);
	    R1002.L1.indicator = (unsigned char)ugrab(1);
	    GPS_PSEUDORANGE(R1002.L1, 24);
	    RANGEDIFF(R1002.L1, 20);
	    R1002.L1.locktime =	(unsigned char)sgrab(7);
	    R1002.L1.ambiguity = (unsigned char)ugrab(8);
	    R1002.L1.CNR = (ugrab(8)) * CARRIER_NOISE_RATIO_UNITS;
	}
#undef R1002
	unknown = false;
	break;

    case 1003:
	/* GPS Basic RTK, L1 & L2 */
	rtcm->rtcmtypes.rtcm3_1003.header.station_id = (unsigned int)ugrab(12);
	rtcm->rtcmtypes.rtcm3_1003.header.tow = (time_t)ugrab(30);
	rtcm->rtcmtypes.rtcm3_1003.header.sync = (bool)ugrab(1);
	rtcm->rtcmtypes.rtcm3_1003.header.satcount = (unsigned short)ugrab(5);
	rtcm->rtcmtypes.rtcm3_1003.header.smoothing = (bool)ugrab(1);
	rtcm->rtcmtypes.rtcm3_1003.header.interval = (unsigned short)ugrab(3);
#define R1003 rtcm->rtcmtypes.rtcm3_1003.rtk_data[i]
	for (i = 0; i < rtcm->rtcmtypes.rtcm3_1003.header.satcount; i++) {
	    R1003.ident = (unsigned short)ugrab(6);
	    R1003.L1.indicator =
		(unsigned char)ugrab(1);
	    GPS_PSEUDORANGE(R1003.L1, 24);
	    RANGEDIFF(R1003.L1, 20);
	    R1003.L1.locktime =	(unsigned char)sgrab(7);
	    R1003.L2.indicator = (unsigned char)ugrab(2);
	    GPS_PSEUDORANGE(R1003.L2, 24);
	    temp = (long)sgrab(20);
	    if (temp == GPS_INVALID_PSEUDORANGE)
		R1003.L2.rangediff = 0;
	    else
		R1003.L2.rangediff = temp * PSEUDORANGE_DIFF_RESOLUTION;
	    R1003.L2.locktime =	(unsigned char)sgrab(7);
	}
#undef R1003
	unknown = false;
	break;

    case 1004:
	/* GPS Extended RTK, L1 & L2 */
	rtcm->rtcmtypes.rtcm3_1004.header.station_id = (unsigned int)ugrab(12);
	rtcm->rtcmtypes.rtcm3_1004.header.tow = (time_t)ugrab(30);
	rtcm->rtcmtypes.rtcm3_1004.header.sync = (bool)ugrab(1);
	rtcm->rtcmtypes.rtcm3_1004.header.satcount = (unsigned short)ugrab(5);
	rtcm->rtcmtypes.rtcm3_1004.header.smoothing = (bool)ugrab(1);
	rtcm->rtcmtypes.rtcm3_1004.header.interval = (unsigned short)ugrab(3);
#define R1004 rtcm->rtcmtypes.rtcm3_1004.rtk_data[i]
	for (i = 0; i < rtcm->rtcmtypes.rtcm3_1004.header.satcount; i++) {
	    R1004.ident = (unsigned short)ugrab(6);
	    R1004.L1.indicator = (bool)ugrab(1);
	    GPS_PSEUDORANGE(R1004.L1, 24);
	    RANGEDIFF(R1004.L1, 20);
	    R1004.L1.locktime =	(unsigned char)sgrab(7);
	    R1004.L1.ambiguity = (unsigned char)ugrab(8);
	    R1004.L1.CNR = ugrab(8) * CARRIER_NOISE_RATIO_UNITS;
	    R1004.L2.indicator = (unsigned char)ugrab(2);
	    GPS_PSEUDORANGE(R1004.L2, 14);
	    RANGEDIFF(R1004.L2, 20);
	    R1004.L2.locktime =	(unsigned char)sgrab(7);
	    R1004.L2.CNR = ugrab(8) * CARRIER_NOISE_RATIO_UNITS;
	}
#undef R1004
	unknown = false;
	break;

    case 1005:
	/* Stationary Antenna Reference Point, No Height Information */
#define R1005 rtcm->rtcmtypes.rtcm3_1005
	R1005.station_id = (unsigned short)ugrab(12);
	ugrab(6);		/* reserved */
	R1005.system = ugrab(3);
	R1005.reference_station = (bool)ugrab(1);
	R1005.ecef_x = sgrab(38) * ANTENNA_POSITION_RESOLUTION;
	R1005.single_receiver = ugrab(1);
	ugrab(1);
	R1005.ecef_y = sgrab(38) * ANTENNA_POSITION_RESOLUTION;
	ugrab(2);
	R1005.ecef_z = sgrab(38) * ANTENNA_POSITION_RESOLUTION;
#undef R1005
	unknown = false;
	break;

    case 1006:
	/* Stationary Antenna Reference Point, with Height Information */
#define R1006 rtcm->rtcmtypes.rtcm3_1006
	R1006.station_id = (unsigned short)ugrab(12);
	(void)ugrab(6);		/* reserved */
	R1006.system = ugrab(3);
	R1006.reference_station = (bool)ugrab(1);
	R1006.ecef_x = sgrab(38) * ANTENNA_POSITION_RESOLUTION;
	R1006.single_receiver = ugrab(1);
	ugrab(1);
	R1006.ecef_y = sgrab(38) * ANTENNA_POSITION_RESOLUTION;
	ugrab(2);
	R1006.ecef_z = sgrab(38) * ANTENNA_POSITION_RESOLUTION;
	R1006.height = ugrab(16) * ANTENNA_POSITION_RESOLUTION;
#undef R1006
	unknown = false;
	break;

    case 1007:
	/* Antenna Descriptor */
	rtcm->rtcmtypes.rtcm3_1007.station_id = (unsigned short)ugrab(12);
	n = (unsigned long)ugrab(8);
	(void)memcpy(rtcm->rtcmtypes.rtcm3_1007.descriptor, buf + 7, n);
	rtcm->rtcmtypes.rtcm3_1007.descriptor[n] = '\0';
	bitcount += 8 * n;
	rtcm->rtcmtypes.rtcm3_1007.setup_id = ugrab(8);
	unknown = false;
	break;

    case 1008:
	/* Antenna Descriptor & Serial Number */
	rtcm->rtcmtypes.rtcm3_1008.station_id = (unsigned short)ugrab(12);
	n = (unsigned long)ugrab(8);
	(void)memcpy(rtcm->rtcmtypes.rtcm3_1008.descriptor, buf + 7, n);
	rtcm->rtcmtypes.rtcm3_1008.descriptor[n] = '\0';
	bitcount += 8 * n;
	rtcm->rtcmtypes.rtcm3_1008.setup_id = ugrab(8);
	n2 = (unsigned long)ugrab(8);
	(void)memcpy(rtcm->rtcmtypes.rtcm3_1008.serial, buf + 9 + n, n2);
	rtcm->rtcmtypes.rtcm3_1008.serial[n2] = '\0';
	//bitcount += 8 * n2;
	unknown = false;
	break;

    case 1009:
	/* GLONASS Basic RTK, L1 Only */
	rtcm->rtcmtypes.rtcm3_1009.header.station_id =
	    (unsigned short)ugrab(12);
	rtcm->rtcmtypes.rtcm3_1009.header.tow = (time_t)ugrab(27);
	rtcm->rtcmtypes.rtcm3_1009.header.sync = (bool)ugrab(1);
	rtcm->rtcmtypes.rtcm3_1009.header.satcount = (unsigned short)ugrab(5);
	rtcm->rtcmtypes.rtcm3_1009.header.smoothing = (bool)ugrab(1);
	rtcm->rtcmtypes.rtcm3_1009.header.interval = (unsigned short)ugrab(3);
#define R1009 rtcm->rtcmtypes.rtcm3_1009.rtk_data[i]
	for (i = 0; i < rtcm->rtcmtypes.rtcm3_1009.header.satcount; i++) {
	    R1009.ident = (unsigned short)ugrab(6);
	    R1009.L1.indicator = (bool)ugrab(1);
	    R1009.L1.channel = (short)ugrab(5) - GLONASS_CHANNEL_BASE;
	    R1009.L1.pseudorange = ugrab(25) * GLONASS_PSEUDORANGE_RESOLUTION;
	    RANGEDIFF(R1009.L1, 20);
	    R1009.L1.locktime =	(unsigned char)sgrab(7);
	}
#undef R1009
	unknown = false;
	break;

    case 1010:
	/* GLONASS Extended RTK, L1 Only */
	rtcm->rtcmtypes.rtcm3_1010.header.station_id =
	    (unsigned short)ugrab(12);
	rtcm->rtcmtypes.rtcm3_1010.header.tow = (time_t)ugrab(27);
	rtcm->rtcmtypes.rtcm3_1010.header.sync = (bool)ugrab(1);
	rtcm->rtcmtypes.rtcm3_1010.header.satcount = (unsigned short)ugrab(5);
	rtcm->rtcmtypes.rtcm3_1010.header.smoothing = (bool)ugrab(1);
	rtcm->rtcmtypes.rtcm3_1010.header.interval = (unsigned short)ugrab(3);
#define R1010 rtcm->rtcmtypes.rtcm3_1010.rtk_data[i]
	for (i = 0; i < rtcm->rtcmtypes.rtcm3_1010.header.satcount; i++) {
	    R1010.ident = (unsigned short)ugrab(6);
	    R1010.L1.indicator = (bool)ugrab(1);
	    R1010.L1.channel = (short)ugrab(5) - GLONASS_CHANNEL_BASE;
	    R1010.L1.pseudorange = ugrab(25) * GLONASS_PSEUDORANGE_RESOLUTION;
	    RANGEDIFF(R1010.L1, 20);
	    R1010.L1.locktime =	(unsigned char)sgrab(7);
	    R1010.L1.ambiguity = (unsigned char)ugrab(7);
	    R1010.L1.CNR = ugrab(8) * CARRIER_NOISE_RATIO_UNITS;
	}
#undef R1010
	unknown = false;
	break;

    case 1011:
	/* GLONASS Basic RTK, L1 & L2 */
	rtcm->rtcmtypes.rtcm3_1011.header.station_id =
	    (unsigned short)ugrab(12);
	rtcm->rtcmtypes.rtcm3_1011.header.tow = (time_t)ugrab(27);
	rtcm->rtcmtypes.rtcm3_1011.header.sync = (bool)ugrab(1);
	rtcm->rtcmtypes.rtcm3_1011.header.satcount = (unsigned short)ugrab(5);
	rtcm->rtcmtypes.rtcm3_1011.header.smoothing = (bool)ugrab(1);
	rtcm->rtcmtypes.rtcm3_1011.header.interval = (unsigned short)ugrab(3);
#define R1011 rtcm->rtcmtypes.rtcm3_1011.rtk_data[i]
	for (i = 0; i < rtcm->rtcmtypes.rtcm3_1011.header.satcount; i++) {
	    R1011.ident = (unsigned short)ugrab(6);
	    R1011.L1.indicator = (bool)ugrab(1);
	    R1011.L1.channel = (short)ugrab(5) - GLONASS_CHANNEL_BASE;
	    R1011.L1.pseudorange = ugrab(25) * GLONASS_PSEUDORANGE_RESOLUTION;
	    RANGEDIFF(R1011.L1, 20);
	    R1011.L1.locktime =	(unsigned char)sgrab(7);
	    R1011.L1.ambiguity = (unsigned char)ugrab(7);
	    R1011.L1.CNR = ugrab(8) * CARRIER_NOISE_RATIO_UNITS;
	    R1011.L2.indicator = (bool)ugrab(1);
	    R1011.L2.channel = (short)ugrab(5) - GLONASS_CHANNEL_BASE;
	    R1011.L2.pseudorange = ugrab(25) * GLONASS_PSEUDORANGE_RESOLUTION;
	    RANGEDIFF(R1011.L2, 20);
	    R1011.L2.locktime =	(unsigned char)sgrab(7);
	    R1011.L2.ambiguity = (unsigned char)ugrab(7);
	    R1011.L2.CNR = ugrab(8) * CARRIER_NOISE_RATIO_UNITS;
	}
#undef R1011
	unknown = false;
	break;

    case 1012:
	/* GLONASS Extended RTK, L1 & L2 */
	rtcm->rtcmtypes.rtcm3_1012.header.station_id =
	    (unsigned short)ugrab(12);
	rtcm->rtcmtypes.rtcm3_1012.header.tow = (time_t)ugrab(27);
	rtcm->rtcmtypes.rtcm3_1012.header.sync = (bool)ugrab(1);
	rtcm->rtcmtypes.rtcm3_1012.header.satcount = (unsigned short)ugrab(5);
	rtcm->rtcmtypes.rtcm3_1012.header.smoothing = (bool)ugrab(1);
	rtcm->rtcmtypes.rtcm3_1012.header.interval = (unsigned short)ugrab(3);
#define R1012 rtcm->rtcmtypes.rtcm3_1012.rtk_data[i]
	for (i = 0; i < rtcm->rtcmtypes.rtcm3_1012.header.satcount; i++) {
	    unsigned int rangeincr;
	    R1012.ident = (unsigned short)ugrab(6);
	    R1012.L1.indicator = (bool)ugrab(1);
	    R1012.L1.channel = (short)ugrab(5) - GLONASS_CHANNEL_BASE;
	    R1012.L1.pseudorange = ugrab(25) * GLONASS_PSEUDORANGE_RESOLUTION;
	    RANGEDIFF(R1012.L1, 20);
	    R1012.L1.locktime =	(unsigned char)ugrab(7);
	    R1012.L1.ambiguity = (unsigned char)ugrab(7);
	    R1012.L1.CNR = (unsigned char)ugrab(8) * CARRIER_NOISE_RATIO_UNITS;
	    R1012.L2.indicator = (bool)ugrab(2);
	    rangeincr = ugrab(14);
	    if (rangeincr == GLONASS_INVALID_RANGEINCR)
		R1012.L2.pseudorange = 0;
	    else
		R1012.L2.pseudorange = (rangeincr * GLONASS_PSEUDORANGE_RESOLUTION);
	    RANGEDIFF(R1012.L2, 20);
	    R1012.L2.locktime =	(unsigned char)sgrab(7);
	    R1012.L2.CNR = (unsigned char)ugrab(8) * CARRIER_NOISE_RATIO_UNITS;
	}
#undef R1012
	unknown = false;
	break;

    case 1013:
	/* System Parameters */
	rtcm->rtcmtypes.rtcm3_1013.station_id = (unsigned short)ugrab(12);
	rtcm->rtcmtypes.rtcm3_1013.mjd = (unsigned short)ugrab(16);
	rtcm->rtcmtypes.rtcm3_1013.sod = (unsigned short)ugrab(17);
	rtcm->rtcmtypes.rtcm3_1013.ncount = (unsigned long)ugrab(5);
	rtcm->rtcmtypes.rtcm3_1013.leapsecs = (unsigned char)ugrab(8);
#define R1013 rtcm->rtcmtypes.rtcm3_1013.announcements[i]
	for (i = 0; i < rtcm->rtcmtypes.rtcm3_1013.ncount; i++) {
	    R1013.id = (unsigned short)ugrab(12);
	    R1013.sync = (bool)ugrab(1);
	    R1013.interval = (unsigned short)ugrab(16);
	}
#undef R1013
	unknown = false;
	break;

    case 1014:
	/* Network Auxiliary Station Data
	 * coordinate difference between one Aux station and the master station
	 */
	rtcm->rtcmtypes.rtcm3_1014.network_id = (int)ugrab(8);
	rtcm->rtcmtypes.rtcm3_1014.subnetwork_id = (int)ugrab(4);
	rtcm->rtcmtypes.rtcm3_1014.stationcount = (char)ugrab(5);
	rtcm->rtcmtypes.rtcm3_1014.master_id = (int)ugrab(12);
	rtcm->rtcmtypes.rtcm3_1014.aux_id = (int)ugrab(12);
	rtcm->rtcmtypes.rtcm3_1014.d_lat =
	    (unsigned short)ugrab(20) * ANTENNA_DEGREE_RESOLUTION;
	rtcm->rtcmtypes.rtcm3_1014.d_lon =
	    (unsigned short)ugrab(21) * ANTENNA_DEGREE_RESOLUTION;
	rtcm->rtcmtypes.rtcm3_1014.d_alt = (unsigned short)ugrab(23) / 1000;
	unknown = false;
	break;

    case 1017:
        /* RTCM 3.1 - 1017
         * GPS Combined Geometric and Ionospheric Correction Differences
         * for all satellites between one Aux station and the master station
         * (same content as both types 1015 and 1016 together, but less size)
	 */
	break;

    case 1019:
        /* RTCM 3.1 - 1020
         * GPS Ephemeris
	 * length 19
	 */
	/* TODO: rtklib has C code for this one.  */
	break;

    case 1020:
        /* RTCM 3.1 - 1020
         * GLONASS Ephemeris
	 * length 45
	 */
	/* TODO: rtklib has C code for this one.  */
	break;

    case 1029:
	/* Text in UTF8 format
         *(max. 127 multibyte characters and max. 255 bytes)
	 */
	rtcm->rtcmtypes.rtcm3_1029.station_id = (unsigned short)ugrab(12);
	rtcm->rtcmtypes.rtcm3_1029.mjd = (unsigned short)ugrab(16);
	rtcm->rtcmtypes.rtcm3_1029.sod = (unsigned short)ugrab(17);
	rtcm->rtcmtypes.rtcm3_1029.len = (unsigned long)ugrab(7);
	rtcm->rtcmtypes.rtcm3_1029.unicode_units = (size_t)ugrab(8);
	(void)memcpy(rtcm->rtcmtypes.rtcm3_1029.text,
		     buf + 12, rtcm->rtcmtypes.rtcm3_1029.unicode_units);
	unknown = false;
	break;

    case 1033:			/* see note in header */
	/* Receiver and Antenna Descriptor
         * Type1033 is a combined Message Types 1007 and 1008
         * and hence contains antenna descriptor and serial number
	 * as well as receiver descriptor and serial number.
	 */
	/* TODO: rtklib has C code for this one.  */
	rtcm->rtcmtypes.rtcm3_1033.station_id = (unsigned short)ugrab(12);
	n = (unsigned long)ugrab(8);
	(void)memcpy(rtcm->rtcmtypes.rtcm3_1033.descriptor, buf + 7, n);
	rtcm->rtcmtypes.rtcm3_1033.descriptor[n] = '\0';
	bitcount += 8 * n;
	rtcm->rtcmtypes.rtcm3_1033.setup_id = ugrab(8);
	n2 = (unsigned long)ugrab(8);
	(void)memcpy(rtcm->rtcmtypes.rtcm3_1033.serial, buf + 9 + n, n2);
	rtcm->rtcmtypes.rtcm3_1033.serial[n2] = '\0';
	bitcount += 8 * n2;
	n3 = (unsigned long)ugrab(8);
	(void)memcpy(rtcm->rtcmtypes.rtcm3_1033.receiver, buf + 10+n+n2, n3);
	rtcm->rtcmtypes.rtcm3_1033.receiver[n3] = '\0';
	bitcount += 8 * n3;
	n4 = (unsigned long)ugrab(8);
	(void)memcpy(rtcm->rtcmtypes.rtcm3_1033.firmware, buf + 11+n+n2+n3, n3);
	rtcm->rtcmtypes.rtcm3_1033.firmware[n4] = '\0';
	//bitcount += 8 * n4;
	// TODO: next is receiver serial number
	unknown = false;
	break;

    case 1043:
        /* RTCM 3.x - 1043
         * SBAS Ephemeris
	 * length 29
	 */
	break;

    case 1044:
        /* RTCM 3.x - 1044
         * QZSS ephemeris
         * length 61
	 */
	/* TODO: rtklib has C code for this one.  */
	break;

    case 1045:
        /* RTCM 3.x - 1045
         * Galileo Ephemeris FNAV data
	 * length 62
	 */
	/* TODO: rtklib has C code for this one.  */
	break;

    case 1046:
        /* RTCM 3.x - 1046
         * Galileo Ephemeris INAV data
	 * length 63
	 */
	/* TODO: rtklib has C code for this one.  */
	break;

    case 1074:
	/* RTCM 3.x
	 * GPS Multi Signal Message
	 */
	break;

    case 1077:
        /* RTCM 3.x - 1077
	 * Full GPS pseudo-ranges, carrier phases, Doppler and
	 * signal strength (high resolution)
         * length 438
	 */
	/* TODO: rtklib has C code for this one.  */
	break;

    case 1087:
        /* RTCM 3.x - 1087
	 * Full GLONASS pseudo-ranges, carrier phases, Doppler and
	 * signal strength (high resolution)
         * length 417 or 427
	 */
	/* TODO: rtklib has C code for this one.  */
	break;

    case 1097:
        /* RTCM 3.x - 1097
         * Full Galileo pseudo-ranges, carrier phases, Doppler and
	 * signal strength (high resolution)
         * length 96
	 */
	/* TODO: rtklib has C code for this one.  */
	break;

    case 1107:
        /* RTCM 3.x - 1107
	 * 'Multiple Signal Message
         * Full SBAS pseudo-ranges, carrier phases, Doppler and
	 * signal strength (high resolution)
         * length 96
	 */
	/* TODO: rtklib has C code for this one.  */
	break;

    case 1114:
	/* RTCM 3.x
	 * QZSS Multi Signal Message
	 */
	break;

    case 1124:
	/* RTCM 3.x
	 * BeiDou Multi Signal Message
	 */
	break;

    default:
	break;
    }
#undef RANGEDIFF
#undef GPS_PSEUDORANGE
#undef sgrab
#undef ugrab
    if ( unknown ) {
	/*
	 * Leader bytes, message length, and checksum won't be copied.
	 * The first 12 bits of the copied payload will be the type field.
	 */
	memcpy(rtcm->rtcmtypes.data, buf+3, rtcm->length);
	gpsd_log(&context->errout, LOG_PROG, "RTCM3: unknown type %d, length %d\n",
	     rtcm->type, rtcm->length);
    }

}

/* *INDENT-ON* */

#endif /* RTCM104V3_ENABLE */