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ZJUT_Nav/TC_NAV_Zjut_post/Src/rt17.c
ZhiQiang_Yang98 79f5c035ab Revert "syn" 
This reverts commit 34a3ce7899a56f426ddb1f91073dfcd1cd373b5b.
2022-11-28 10:49:41 +08:00

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/*------------------------------------------------------------------------------
* rt17.c : Trimble RT-17 dependent functions
*
* Copyright (C) 2016 Daniel A. Cook, All rights reserved.
* Copyright (C) 2020 T.TAKASU, All rights reserved.
*
* references:
* [1] https://github.com/astrodanco/RTKLIB/tree/cmr/src/rcv/rt17.c
* [2] Trimble, Trimble OEM BD9xx GNSS Receiver Family IDC, version 4.82
* Revision A, December, 2013
*
* version : $Revision:$ $Date:$
* history : 2014/08/26 1.0 imported from GitHub (ref [1])
* modified to get initial week number
* modified obs types for raw obs data
* function added to output message type
* 2014/09/06 1.1 Remove prehistorical revision history
* Remove dead code
* Fix len vs. plen typo
* Check week/time valid flag in GSOF 16 message
* Set time when reading GSOF messages, where possible.
* 2016/06/16 1.2 Refactored
* 2016/07/16 1.3 modified by T.T
* raw->strfmt -> raw->format
* int free_rt17() -> void free_rt17()
* 2016/07/29 1.4 suppress warning
* 2017/04/11 1.5 (char *) -> (signed char *)
* 2020/11/30 1.6 use integer type in stdint.h
*-----------------------------------------------------------------------------*/
/*
| Trimble real-time binary data stream and file handler functions.
|
| Written in July 2014 by Daniel A. Cook, for inclusion into the RTKLIB library.
| Copyright (C) 2014, 2016 by Daniel A. Cook. All Rights Reserved.
|
| Here we implement four public functions, one for reading Trimble real-time
| binary data streams and another for reading log files containng data in the
| same format, a third to initialize RT17 related memory storage and a fourth
| to free up RT17 related memory storage. This real-time streaming data format,
| sometimes called RT-17, was designed by Trimble for use by Trimble receivers.
| Trimble receivers with the "Real-Time Survey Data" or "Binary Outputs" options
| can output this data. The RT-17 moniker refers to the GPS observables data
| record (record type 0) itself. There is also a GNSS observables data record
| (record type 6), which is referred to as RT-27. We also wish to handle RT-27
| data records, but lack sufficient documentation to do so.
|
| Notes:
|
| To specify receiver dependent options, set raw->opt to the following case
| sensitive option strings separated by spaces.
|
| Receiver dependent options:
|
| -EPHALL : Input all ephemerides
| -WEEK=n : Explicitly set starting GPS week number
|
| Neither the Trimble RT-17 observables packets nor the ION / UTC data packets
| contain the GPS week number. By default the current computer "now" time is
| used to determine the GPS week number. This works well in real time, but
| can be problematic when later converting and/or post processing recorded
| data. When recording data, also enable either GSOF Position & Time (1) or
| GSOF Current Time (16) messages on the same serial port along with the
| RT-17 Real-Time Survey Data output. For best results enable the GSOF
| message(s) and get them streaming prior to enabling the RT-17 messages.
|
| If desired the -WEEK=n option can be specified when converting or post
| processing recorded data to explicitly set the starting GPS week number.
| This option overrides anything and everything, including the current
| computer "now" time and any GSOF or other messages read from the raw
| data stream or recorded file. Note that the GPS week number explicitly
| specified with the -WEEK=n option GPS is automatically incremented when
| and if a subsequent GPS week number rollover occurs in the raw data.
|
| In addition to enabling RT-17 Real-Time Survey Data output, it is very
| helpful to also enable GSOF Position & Time (1) or GSOF Current Time (16)
| messages on the same serial port. This allows the GPS week number to be
| determined without using the current computer "now" time or the -WEEK=n
| option. Although not as important for real-time streaming data use where
| the current computer "now" time can be used to determine the current GPS
| week number, it becomes more important when recording files for later
| conversion and/or post processing. For best results enable the GSOF
| message(s) and get them streaming prior to enabling the RT-17 messages.
|
| Support is provided for the following Trimble RT-17 packet Types:
|
| Raw Observation Satellite ION/UTC
| Format Data Ephemerides Parameters GSOF
| ------- --------------- ---------------- ---------------- ------------
| Trimble 0x57 (RAWDATA) 0x55 (RETSVDATA) 0x55 (RETSVDATA) 1, 16,
| RT-17 Recordtype 0 & 7 Subtype 1 Subtype 3 26, 41
|
| When the -WEEK=n option is NOT used, the GPS week number is set from any
| RAWDATA record type 7 or GENOUT (GSOF) 1, 16, 26, 41 records encountered
| in the raw data stream. These messages are only used to obtain the GPS
| WEEK number and are not used for any other purpose.
|
| Support is not provided for the GPS L2C or L5 signals. Those would likely
| require Trimble RT-27 protocol support. Support for that and much more
| could easily be added by anyone with the required RAWDATA record type
| 6 documentation.
|
| For Trimble GPS receivers which are capable of RT-17 binary output, the
| receiver and/or receiver configuration software generally provide several
| RT-17 binary output options:
|
| 1. Compact format aka Concise format
| (RECOMMENDED)
|
| This option causes the raw satellite data to be streamed in a more compact
| format. The compact format does not include L2 DOPPLER observables.
|
| 2. Expanded format
|
| This is usually the default format if compact format is not enabled. The
| only advantage of this format over compact format is that L2 DOPPLER
| observables are output when used in combination with the Real Time
| Enhancements option. Otherwise this format just consumes more bandwidth
| and/or file space than compact format while offering no other advantages.
|
| 3. Real Time Enhancements, aka Real-time Enhanced format, aka R-T FLAGS
|
| This option adds extra data to the raw satellite data output by the
| receiver. When used in combination with expanded format, L2 DOPPLER
| observables are output. L2 DOPPLER can be used by RTKLIB.
|
| 3. Measurements
| (REQUIRED)
|
| If your configuration has a measurements option, enable it. Measurements
| are the raw satellite data. If you don't see this option then it is
| implied and enabled by default.
|
| 4. Ephermeris AKA Stream Ephemeris
| (HIGHLY RECOMMENDED)
|
| This option causes satellite ephemerides and UTC / ION data to be streamed
| along with the raw satellite data. Streamed ephemerides and UTC / ION data
| consume very little extra bandwidth in the stream and/or space in a file.
| In most situations with most applications you will need them as well.
|
| 5. Positions AKA Stream Positions
| (NOT RECOMMENDED)
|
| Streamed postions are of no use to RTKLIB. They will be ignored. RTKLIB
| computes positions from the raw satellite data. It has no use for the
| receiver's position solutions. Streamed positions also consume
| considerable bandwidth in the stream and/or space in a file.
|
| 6. Positions Only
| (HIGHLY NOT RECOMMENDED)
|
| Enabling the positions only option causes only positions and nothing else
| to be output, including no raw satellite data and no ephemerides and no
| ION / UTC data.
|
| Design notes:
|
| This source code handles GPS L1/L2 only. RT-17 is GPS. RT27 is GNSS.
| If you have RT27 (RAWDATA 57h record type 6) documentation, please
| forward it to the author.
|
| An RT-17 real-time survey data message is a series of RAWDATA (57h,
| Real-time survey data report) and RETSVDATA (55h, Satellite information
| report) packets.
|
| Each assembled RAWDATA message in an RT-17 packet stream may contain
| any of the following: Compact Format raw satellite measurements, Expanded
| Format raw satellite measurements, a receiver computed position or an
| event mark. Receiver computed positions and event marks are of no
| interest to RTKLIB, therefore we ignore them.
|
| Each RETSVDATA message in an RT-17 packet stream may contain any one
| of the following: SV flags indicating tracking, a GPS Ephemeris, a GPS
| Almanac, ION / UTC Data or an Extended GPS Almanac. Of these only
| the GPS Ephemeris and the ION / UTC Data are of interest to RTKLIB.
| In practice only GPS Ephemeris and ION / UTC Data are transmitted.
| Some receivers can be set to transmit them at regular intervals
| rather than only when they change.
|
| Certain simplifying assumptions are made concerning the way in which
| RAWDATA and GENOUT packets are transmitted in the stream or stored
| into the file.
|
| Therefore it is assumed that:
|
| 1. RAWDATA and GENOUT packets are never interleaved or interspersed
| with packets of other types.
|
| 2. The sequence of page frames in a RAWDATA message are transmitted in the
| stream or stored into a file as packets in order from first to last.
| RAWDATA page numbers are one based. That is, 1 of n, 2 of n, 3 of n,
| ..., to 15 of 15 for a total of 15 possible pages. We check for this
| ordering. RAWDATA messages can therefore reach almost 4K in total
| length. We check for potential buffer overflows in the input_rt17()
| function.
|
| 3. The Record Interpretation Flags (RIF) field is repeated within the
| page frame of every page making up a single RAWDATA message. It is
| assumed that this is redundant and that the actual value of the record
| interpretation flags does not change from one page to the next within
| a single RAWDATA message. We check for this too.
|
| 4. The sequence of pages in a GENOUT message are transmitted in the
| stream or stored into a file as packets in order from first to last.
| GENOUT page numbers are zero based. That is, 0 of n, 1 of n, 2 of n,
| ..., to 255 of 255 for a total of 256 possible pages. We check for
| this ordering. GENOUT messages can therefore reach almost 64K in
| total length. Such a large GENOUT message could exceed our maximum
| buffer size. We check for potential buffer overflows in the
| input_rt17() function.
|
| This code was tested using RT-17 data output from the following receivers:
|
| 1. Trimble 4000SSI, firmware version 7.32
| 2. Trimble 5700, firmware version 2.32
| 3. Spectra Precision Epoch 25 Base, firmware version 2.32
|
| By convention functions within this source file appear in alphabetical
| order. Public functions appear as a set first (there are only two of
| them), followed by private functions as a set. Because of this, forward
| definitions are required for the private functions. Please keep that
| in mind when making changes to this source file.
|
| References:
|
| 1. Trimble Serial Reference Specification, Version 4.82, Revision A,
| December 2013. Though not being in any way specific to the BD9xx
| family of receivers, a handy downloadable copy of this document
| is contained in the "Trimble OEM BD9xx GNSS Receiver Family ICD"
| document located at <http://www.trimble.com/OEM_ReceiverHelp/
| v4.85/en/BinaryInterfaceControlDoc.pdf>
|
| 2. Trimble General Serial Output Format (GSOF)
| <http://www.trimble.com/OEM_ReceiverHelp/v4.85/en/GSOFmessages_GSOF.html>
|
| 3. ICD-GPS-200C, Interface Control Document, Revision C, 10 October 1993
| <http://www.gps.gov/technical/icwg/ICD-GPS-200C.pdf>
|
| 4. IS-GPS-200H, Interface Specification, 24 September 2013
| <http://www.gps.gov/technical/icwg/IS-GPS-200H.pdf>
|
| 5. RTKLIB Version 2.4.2 Manual, April 29 2013
| <http://www.rtklib.com/prog/manual_2.4.2.pdf>
*/
/* Included files: */
#include "rtklib.h"
/* General purpose flag bits masks: */
#define M_BIT0 (1 << 0)
#define M_BIT1 (1 << 1)
#define M_BIT2 (1 << 2)
#define M_BIT3 (1 << 3)
#define M_BIT4 (1 << 4)
#define M_BIT5 (1 << 5)
#define M_BIT6 (1 << 6)
#define M_BIT7 (1 << 7)
#define M_BIT8 (1 << 8)
#define M_BIT9 (1 << 9)
#define M_BIT10 (1 << 10)
#define M_BIT11 (1 << 11)
#define M_BIT12 (1 << 12)
#define M_BIT13 (1 << 13)
#define M_BIT14 (1 << 14)
#define M_BIT15 (1 << 15)
/* Constant definitions: */
#define STX 2 /* Start of packet character */
#define ETX 3 /* End of packet character */
#define GENOUT 0x40 /* General Serial Output Format (GSOF) */
#define RETSVDATA 0x55 /* Satellite information reports */
#define RAWDATA 0x57 /* Position or real-time survey data report */
#define MBUFF_LENGTH 8192 /* Message buffer length */
#define PBUFF_LENGTH (4+255+2) /* Packet buffer length */
/* Record Interpretation Flags bit masks: */
#define M_CONCISE M_BIT0 /* Concise format */
#define M_ENHANCED M_BIT1 /* Enhanced record with real-time flags and IODE information */
/* rt17.flag bit definitions: */
#define M_WEEK_OPTION M_BIT0 /* GPS week number set by WEEK=n option */
#define M_WEEK_EPH M_BIT1 /* GPS week number set by ephemeris week */
#define M_WEEK_TIME M_BIT2 /* GPS week set by computer time */
#define M_WEEK_SCAN M_BIT3 /* WEEK=n option already looked for, no need to do it again */
/* Data conversion macros: */
#define I1(p) (*((int8_t *)(p))) /* One byte signed integer */
#define U1(p) (*((uint8_t *)(p))) /* One byte uint32_teger */
#define I2(p) ReadI2(p) /* Two byte signed integer */
#define U2(p) ReadU2(p) /* Two byte uint32_teger */
#define I4(p) ReadI4(p) /* Four byte signed integer */
#define U4(p) ReadU4(p) /* Four byte uint32_teger */
#define R4(p) ReadR4(p) /* IEEE S_FLOAT floating point number */
#define R8(p) ReadR8(p) /* IEEE T_FLOAT floating point number */
/* Internal structure definitions. */
typedef union {uint16_t u2; uint8_t c[2];} ENDIAN_TEST;
/* GENOUT 0x40 message types: */
static const char *GSOFTable[] = {
/* 00 */ NULL,
/* 01 */ "Position Time",
/* 02 */ "Latitude Longitude Height",
/* 03 */ "ECEF Position",
/* 04 */ "Local Datum LLH Position",
/* 05 */ "Local Zone ENU Position",
/* 06 */ "ECEF Delta",
/* 07 */ "Tangent Plane Delta",
/* 08 */ "Velocity Data",
/* 09 */ "DOP Information",
/* 10 */ "Clock Information",
/* 11 */ "Position VCV Information",
/* 12 */ "Position Sigma Information",
/* 13 */ "SV Brief Information",
/* 14 */ "SV Detailed Information",
/* 15 */ "Receiver Serial Number",
/* 16 */ "Current Time UTC",
/* 17 */ NULL,
/* 18 */ NULL,
/* 19 */ NULL,
/* 20 */ NULL,
/* 21 */ NULL,
/* 22 */ NULL,
/* 23 */ NULL,
/* 24 */ NULL,
/* 25 */ NULL,
/* 26 */ "Position Time UTC",
/* 27 */ "Attitude Information",
/* 28 */ NULL,
/* 29 */ NULL,
/* 30 */ NULL,
/* 31 */ NULL,
/* 32 */ NULL,
/* 33 */ "All SV Brief Information",
/* 34 */ "All SV Detailed Information",
/* 35 */ "Received Base Information",
/* 36 */ NULL,
/* 37 */ "Battery and Memory Information",
/* 38 */ NULL,
/* 39 */ NULL,
/* 40 */ "L-Band Status Information",
/* 41 */ "Base Position and Quality Indicator"
};
/* RAWDATA 0x57 message types: */
static const char *RawdataTable[] = {
/* 00 */ "Real-time GPS Survey Data, type 17",
/* 01 */ "Position Record, type 11",
/* 02 */ "Event Mark",
/* 03 */ NULL,
/* 04 */ NULL,
/* 05 */ NULL,
/* 06 */ "Real-time GNSS Survey Data, type 27",
/* 07 */ "Enhanced Position Record, type 29"
};
/* RETSVDATA 0x55 message types: */
static const char *RetsvdataTable[] = {
/* 00 */ "SV Flags",
/* 01 */ "GPS Ephemeris",
/* 02 */ "GPS Almanac",
/* 03 */ "ION / UTC Data",
/* 04 */ "Disable Satellite, depreciated",
/* 05 */ "Enable Satellite, depreciated",
/* 06 */ NULL,
/* 07 */ "Extended GPS Almanac",
/* 08 */ "GLONASS Almanac",
/* 09 */ "GLONASS Ephemeris",
/* 10 */ NULL,
/* 11 */ "Galileo Ephemeris",
/* 12 */ "Galileo Almanac",
/* 13 */ NULL,
/* 14 */ "QZSS Ephemeris",
/* 15 */ NULL,
/* 16 */ "QZSS Almanac",
/* 17 */ NULL,
/* 18 */ NULL,
/* 19 */ NULL,
/* 20 */ "SV Flags",
/* 21 */ "BeiDou Ephemeris",
/* 22 */ "BeiDou Almanac"
};
/*
| Typedefs.
*/
typedef struct { /* RT17 information struct type */
uint8_t *MessageBuffer; /* Message buffer */
uint8_t *PacketBuffer; /* Packet buffer */
double Tow; /* Receive time of week */
uint32_t Flags; /* Miscellaneous internal flag bits */
uint32_t MessageBytes; /* Number of bytes in message buffer */
uint32_t MessageLength; /* Message length (bytes) */
uint32_t PacketBytes; /* How many packet bytes have been read so far */
uint32_t PacketLength; /* Total size of packet to be read */
uint32_t Page; /* Last page number */
uint32_t Reply; /* Current reply number */
int Week; /* GPS week number */
} rt17_t;
/*
| Internal private function forward declarations (in alphabetical order):
*/
static int CheckPacketChecksum(uint8_t *PacketBuffer);
static void ClearMessageBuffer(rt17_t *rt17);
static void ClearPacketBuffer(rt17_t *rt17);
static int DecodeBeidouEphemeris(raw_t *Raw);
static int DecodeGalileoEphemeris(raw_t *Raw);
static int DecodeGLONASSEphemeris(raw_t *Raw);
static int DecodeGPSEphemeris(raw_t *Raw);
static int DecodeGSOF(raw_t *Raw);
static int DecodeGSOF1(raw_t *Raw, uint8_t *p);
static int DecodeGSOF3(raw_t *Raw, uint8_t *p);
static int DecodeGSOF15(raw_t *Raw, uint8_t *p);
static int DecodeGSOF16(raw_t *Raw, uint8_t *p);
static int DecodeGSOF26(raw_t *Raw, uint8_t *p);
static int DecodeGSOF41(raw_t *Raw, uint8_t *p);
static int DecodeIONAndUTCData(raw_t *Raw);
static int DecodeQZSSEphemeris(raw_t *Raw);
static int DecodeRawdata(raw_t *Raw);
static int DecodeRetsvdata(raw_t *Raw);
static int DecodeType17(raw_t *Raw, uint32_t rif);
static int DecodeType29(raw_t *Raw);
static int GetWeek(raw_t *Raw, double tow);
static int16_t ReadI2(uint8_t *p);
static int32_t ReadI4(uint8_t *p);
static float ReadR4(uint8_t *p);
static double ReadR8(uint8_t *p);
static uint16_t ReadU2(uint8_t *p);
static uint32_t ReadU4(uint8_t *p);
static void SetWeek(raw_t *Raw, int Week, double tow);
static int SyncPacket(rt17_t *rt17, uint8_t Data);
static void UnwrapRawdata(rt17_t *rt17, uint32_t *rif);
static void UnwrapGenout(rt17_t *rt17);
/* Public functions (in alphabetical order): */
/* free_rt17 - Free up RT17 dependent private storage */
EXPORT void free_rt17(raw_t *Raw)
{
rt17_t *rt17 = NULL;
if (Raw->format != STRFMT_RT17)
return;
if ((rt17 = (rt17_t*) Raw->rcv_data))
{
if (rt17->MessageBuffer)
{
memset(rt17->MessageBuffer, 0, MBUFF_LENGTH);
free(rt17->MessageBuffer);
rt17->MessageBuffer = NULL;
}
if (rt17->PacketBuffer)
{
memset(rt17->PacketBuffer, 0, PBUFF_LENGTH);
free(rt17->PacketBuffer);
rt17->PacketBuffer = NULL;
}
memset(rt17, 0, sizeof(rt17_t));
free(rt17);
Raw->rcv_data = NULL;
}
}
/* init_rt17 = Initialize RT17 dependent private storage */
EXPORT int init_rt17(raw_t *Raw)
{
rt17_t *rt17 = NULL;
uint8_t *MessageBuffer = NULL, *PacketBuffer = NULL;
if (Raw->format != STRFMT_RT17)
return 0;
if (!(rt17 = (rt17_t*) calloc(1, sizeof(rt17_t))))
{
tracet(0, "RT17: unable to allocate RT17 dependent private data structure.\n");
return 0;
}
Raw->rcv_data = (void*) rt17;
if (!(MessageBuffer = (uint8_t*) calloc(MBUFF_LENGTH, sizeof(uint8_t))))
{
tracet(0, "RT17: unable to allocate RT17 message buffer.\n");
free_rt17(Raw);
return 0;
}
rt17->MessageBuffer = MessageBuffer;
if (!(PacketBuffer = (uint8_t*) calloc(PBUFF_LENGTH, sizeof(uint8_t))))
{
tracet(0, "RT17: unable to allocate RT17 packet buffer.\n");
free_rt17(Raw);
return 0;
}
rt17->PacketBuffer = PacketBuffer;
return 1;
}
/*
| input_rt17 - Read an RT-17 mesasge from a raw data stream
|
| Returns:
|
| -1: error message
| 0: no message (tells caller to please read more data from the stream)
| 1: input observation data
| 2: input ephemeris
| 9: input ion/utc parameter
|
| Each message begins with a 4-byte header, followed by the bytes of data in the packet,
| and the packet ends with a 2-byte trailer. Byte 3 is set to 0 (00h) when the packet
| contains no data.
*/
EXPORT int input_rt17(raw_t *Raw, uint8_t Data)
{
rt17_t *rt17 = (rt17_t*) Raw->rcv_data;
uint8_t *MessageBuffer = rt17->MessageBuffer;
uint8_t *PacketBuffer = rt17->PacketBuffer;
uint32_t Page, Pages, Reply;
int Ret = 0;
/* If no current packet */
if (rt17->PacketBytes == 0)
{
/* Find something that looks like a packet. */
if (SyncPacket(rt17, Data))
{
/* Found one. */
rt17->PacketLength = 4 + PacketBuffer[3] + 2; /* 4 (header) + length + 2 (trailer) */
rt17->PacketBytes = 4; /* We now have four bytes in the packet buffer */
}
/* Continue reading the rest of the packet from the stream */
return 0;
}
/* Store the next byte of the packet */
PacketBuffer[rt17->PacketBytes++] = Data;
/*
| Keep storing bytes into the current packet
| until we have what we think are all of them.
*/
if (rt17->PacketBytes < rt17->PacketLength)
return 0;
/*
| At this point we think have an entire packet.
| The prospective packet must end with an ETX.
*/
if (rt17->PacketBuffer[rt17->PacketLength-1] != ETX)
{
tracet(2, "RT17: Prospective packet did not end with an ETX character. Some data lost.\n");
ClearPacketBuffer(rt17);
return 0;
}
/*
| We do indeed have an entire packet.
| Check the packet checksum.
*/
if (!CheckPacketChecksum(PacketBuffer))
{
tracet(2, "RT17: Packet checksum failure. Packet discarded.\n");
ClearPacketBuffer(rt17);
return 0;
}
if (Raw->outtype)
sprintf(Raw->msgtype, "RT17 0x%02X (%4d)", PacketBuffer[2], rt17->PacketLength);
/* If this is a SVDATA packet, then process it immediately */
if (PacketBuffer[2] == RETSVDATA)
{
Ret = DecodeRetsvdata(Raw);
ClearPacketBuffer(rt17);
return Ret;
}
/* Accumulate a sequence of RAWDATA packets (pages) */
if (PacketBuffer[2] == RAWDATA)
{
Page = PacketBuffer[5] >> 4;
Pages = PacketBuffer[5] & 15;
Reply = PacketBuffer[6];
/*
| If this is the first RAWDATA packet in a sequence of RAWDATA packets,
| then make sure it's page one and not a packet somewhere in the middle.
| If not page one, then skip it and continue reading from the stream
| until we find one that starts at page one. Otherwise make sure it is
| a part of the same requence of packets as the last one, that it's
| page number is in sequence.
*/
if (rt17->MessageBytes == 0)
{
if (Page != 1)
{
tracet(2, "RT17: First RAWDATA packet is not page #1. Packet discarded.\n");
ClearPacketBuffer(rt17);
return 0;
}
rt17->Reply = PacketBuffer[6];
}
else if ((Reply != rt17->Reply) || (Page != (rt17->Page + 1)))
{
tracet(2, "RT17: RAWDATA packet sequence number mismatch or page out of order. %u RAWDATA packets discarded.\n", Page);
ClearMessageBuffer(rt17);
ClearPacketBuffer(rt17);
return 0;
}
/* Check for message buffer overflow */
if ((rt17->MessageBytes + rt17->PacketBytes) > MBUFF_LENGTH)
{
tracet(2, "RT17: Buffer would overflow. %u RAWDATA packets discarded.\n", Page);
ClearMessageBuffer(rt17);
ClearPacketBuffer(rt17);
return 0;
}
memcpy(MessageBuffer + rt17->MessageBytes, PacketBuffer, rt17->PacketBytes);
rt17->MessageBytes += rt17->PacketBytes;
rt17->MessageLength += rt17->PacketLength;
ClearPacketBuffer(rt17);
if (Page == Pages)
{
Ret = DecodeRawdata(Raw);
ClearMessageBuffer(rt17);
return Ret;
}
rt17->Page = Page;
return 0;
}
/* Accumulate a sequence of GENOUT (GSOF) packets (pages) */
if (PacketBuffer[2] == GENOUT)
{
Reply = PacketBuffer[4];
Page = PacketBuffer[5];
Pages = PacketBuffer[6];
/*
| If this is the first GENOUT packet in a sequence of GENOUT packets,
| then make sure it's page zero and not a packet somewhere in the middle.
| If not page zero, then skip it and continue reading from the stream
| until we find one that starts at page zero. Otherwise make sure it is
| a part of the same requence of packets as the last one, that it's
| page number is in sequence.
*/
if (rt17->MessageBytes == 0)
{
if (Page != 0)
{
tracet(3, "RT17: First GENOUT packet is not page #0. Packet discarded.\n");
ClearPacketBuffer(rt17);
return 0;
}
rt17->Reply = PacketBuffer[4];
}
else if ((Reply != rt17->Reply) || (Page != (rt17->Page + 1)))
{
tracet(2, "RT17: GENOUT packet sequence number mismatch or page out of order. %u GENOUT packets discarded.\n", Page);
ClearMessageBuffer(rt17);
ClearPacketBuffer(rt17);
return 0;
}
/* Check for message buffer overflow. */
if ((rt17->MessageBytes + rt17->PacketBytes) > MBUFF_LENGTH)
{
tracet(2, "RT17: Buffer would overflow. %u GENOUT packets discarded.\n", Page);
ClearMessageBuffer(rt17);
ClearPacketBuffer(rt17);
return 0;
}
memcpy(MessageBuffer + rt17->MessageBytes, PacketBuffer, rt17->PacketBytes);
rt17->MessageBytes += rt17->PacketBytes;
rt17->MessageLength += rt17->PacketLength;
ClearPacketBuffer(rt17);
if (Page == Pages)
{
Ret = DecodeGSOF(Raw);
ClearMessageBuffer(rt17);
return Ret;
}
rt17->Page = Page;
return 0;
}
/*
| If we fall through to here, then the packet is not one that we support
| (and hence we can't really even get here). Dump the packet on the floor
| and continue reading from the stream.
*/
tracet(2, "RT17: Packet is not GENOUT, RAWDATA or RETSVDATA. Packet discarded.\n");
ClearPacketBuffer(rt17);
return 0;
}
/*
| input_rt17f - Read an RT-17 mesasge from a file
|
| Returns:
|
| -2: End of file (EOF)
| -1: error message
| 0: no message
| 1: input observation data
| 2: input ephemeris
| 9: input ion/utc parameter
*/
EXPORT int input_rt17f(raw_t *Raw, FILE *fp)
{
int i, Data, Ret;
for (i = 0; i < 4096; i++)
{
if ((Data = fgetc(fp)) == EOF) return -2;
if ((Ret = input_rt17(Raw, (uint8_t) Data))) return Ret;
}
return 0; /* return at every 4k bytes */
}
/*
| Private functions (in alphabetical order):
*/
/*
| CheckPacketChecksum - Check the packet checksum
|
| The checksum is computed as the modulo 256 (unsigned 8-bit integer) sum
| of the packet contents starting with the status byte, including the
| packet type byte, length byte, data bytes and ending with the last byte
| of the data bytes. It does not include the STX leader, the ETX trailer
| nor the checksum byte.
*/
static int CheckPacketChecksum(uint8_t *PacketBuffer)
{
uint8_t Checksum = 0;
uint8_t *p = &PacketBuffer[1]; /* Starting with status */
uint32_t Length = PacketBuffer[3] + 3; /* status, type, length, data */
/* Compute the packet checksum */
while (Length > 0)
{
Checksum += *p++;
Length--;
}
/*
| Make sure our computed checksum matches the one at the end of the packet.
| (Note that the above loop by design very conveniently left *p pointing
| to the checksum byte at the end of the packet.)
*/
return (Checksum == *p);
}
/* ClearMessageBuffer - Clear the raw data stream buffer */
static void ClearMessageBuffer(rt17_t *rt17)
{
uint8_t *MessageBuffer = rt17->MessageBuffer;
int i;
for (i = 0; i < 4; i++)
MessageBuffer[i] = 0;
rt17->MessageLength = rt17->MessageBytes = 0;
rt17->Reply = 0;
}
/* ClearPacketBuffer - Clear the packet buffer */
static void ClearPacketBuffer(rt17_t *rt17)
{
uint8_t *PacketBuffer = rt17->PacketBuffer;
int i;
for (i = 0; i < 4; i++)
PacketBuffer[i] = 0;
rt17->PacketLength = rt17->PacketBytes = 0;
}
/*
| DecodeBeidouEphemeris - Decode a Beidou Ephemeris record
|
| Returns:
|
| -1: error message
| 2: input ephemeris
|
| See reference #1 above for documentation of the RETSVDATA Beidou Ephemeris.
*/
static int DecodeBeidouEphemeris(raw_t *Raw)
{
tracet(3, "DecodeBeidouEphemeris(); not yet implemented.\n");
return 0;
#if 0
rt17_t *rt17 = (rt17_t*) Raw->rcv_data;
uint8_t *p = rt17->PacketBuffer;
int prn, sat, toc, tow;
uint32_t Flags, toe;
double sqrtA;
eph_t eph={0};
tracet(3, "RT17: DecodeBeidouEphemeris(); Length=%d\n", rt17->PacketLength);
if (rt17->PacketLength < 182)
{
tracet(2, "RT17: RETSVDATA packet length %d < 182 bytes. GPS ephemeris packet discarded.\n", rt17->PacketLength);
return -1;
}
prn = U1(p+5);
if (!(sat=satno(SYS_CMP, prn)))
{
tracet(2, "RT17: Beidou ephemeris satellite number error, PRN=%d.\n", prn);
return -1;
}
eph.week = U2(p+6); /* 006-007: Ephemeris Week number (weeks) */
eph.iodc = U2(p+8); /* 008-009: IODC */
/* Reserved byte */ /* 010-010: RESERVED */
eph.iode = U1(p+11); /* 011-011: IODE */
tow = I4(p+12); /* 012-015: TOW */
toc = I4(p+16); /* 016-019: TOC (seconds) */
toe = U4(p+20); /* 020-023: TOE (seconds) */
eph.tgd[0]= R8(p+24); /* 024-031: TGD (seconds) */
eph.f2 = R8(p+32); /* 032-029: AF2 (seconds/seconds^2) */
eph.f1 = R8(p+40); /* 040-047: AF1 (seconds/seconds) */
eph.f0 = R8(p+48); /* 048-055: AF0 (seconds) */
eph.crs = R8(p+56); /* 056-063: CRS (meters) */
eph.deln = R8(p+64); /* 064-071: DELTA N (semi-circles/second) */
eph.M0 = R8(p+72); /* 072-079: M SUB 0 (semi-circles) */
eph.cuc = R8(p+80); /* 080-087: CUC (semi-circles) */
eph.e = R8(p+88); /* 088-095: ECCENTRICITY (dimensionless) */
eph.cus = R8(p+96); /* 096-103: CUS (semi-circles) */
sqrtA = R8(p+104); /* 104-111: SQRT A (meters ^ 0.5) */
eph.cic = R8(p+112); /* 112-119: CIC (semi-circles) */
eph.OMG0 = R8(p+120); /* 120-127: OMEGA SUB 0 (semi-circles) */
eph.cis = R8(p+128); /* 128-135: CIS (semi-circlces) */
eph.i0 = R8(p+136); /* 136-143: I SUB 0 (semi-circles) */
eph.crc = R8(p+144); /* 144-151: CRC (meters) */
eph.omg = R8(p+152); /* 152-159: OMEGA (semi-circles?) */
eph.OMGd = R8(p+160); /* 160-167: OMEGA DOT (semi-circles/second) */
eph.idot = R8(p+168); /* 168-175: I DOT (semi-circles/second) */
Flags = U4(p+176); /* 176-179: FLAGS */
/*
| Multiply these by PI to make semi-circle units into radian units for RTKLIB.
*/
eph.deln *= SC2RAD;
eph.i0 *= SC2RAD;
eph.idot *= SC2RAD;
eph.M0 *= SC2RAD;
eph.omg *= SC2RAD;
eph.OMG0 *= SC2RAD;
eph.OMGd *= SC2RAD;
/*
| As specifically directed to do so by Reference #1, multiply these by PI.
| to make semi-circle units into radian units, which is what RTKLIB needs.
*/
eph.cic *= SC2RAD;
eph.cis *= SC2RAD;
eph.cuc *= SC2RAD;
eph.cus *= SC2RAD;
/*
| Select the correct curve fit interval as per ICD-GPS-200 sections
| 20.3.3.4.3.1 and 20.3.4.4 using IODC, fit flag and Table 20-XII.
*/
if (Flags & M_BIT10) /* Subframe 2, word 10, bit 17 (fit flag) */
{
if ((eph.iodc >= 240) && (eph.iodc <= 247))
eph.fit = 8;
else if (((eph.iodc >= 248) && (eph.iodc <= 255)) || (eph.iodc == 496))
eph.fit = 14;
else if ((eph.iodc >= 497) && (eph.iodc <= 503))
eph.fit = 26;
else if ((eph.iodc >= 504) && (eph.iodc <= 510))
eph.fit = 50;
else if ((eph.iodc == 511) || ((eph.iodc >= 752) && (eph.iodc <= 756)))
eph.fit = 74;
else if ((eph.iodc >= 757) && (eph.iodc <= 763))
eph.fit = 98;
else if (((eph.iodc >= 764) && (eph.iodc <= 767)) || ((eph.iodc >= 1008) && (eph.iodc <= 1010)))
eph.fit = 122;
else if ((eph.iodc >= 1011) && (eph.iodc <= 1020))
eph.fit = 146;
else
eph.fit = 6;
}
else
eph.fit = 4;
eph.flag = (Flags & M_BIT0); /* Subframe 1, word 4, bit 1, Data flag for L2 P-code */
eph.code = (Flags >> 1) & 3; /* Subframe 1, word 3, bits 11-12, Codes on L2 channel */
eph.svh = (Flags >> 4) & 127; /* Subframe 1, word 3, bits 17-22, SV health from ephemeris */
eph.sva = (Flags >> 11) & 15; /* Subframe 1, word 3, bits 13-16, User Range Accuracy index */
eph.A = sqrtA * sqrtA;
eph.toes = toe;
eph.toc = bdt2gpst(bdt2time(eph.week, toc));
eph.toe = bdt2gpst(bdt2time(eph.week, toe));
eph.ttr = bdt2gpst(bdt2time(eph.week, tow));
tracet(3, "RT17: DecodeBeidouEphemeris(); SAT=%d, IODC=%d, IODE=%d, WEEK=%d.\n", sat, eph.iodc, eph.iode, eph.week);
if (!strstr(Raw->opt,"-EPHALL"))
{
if (eph.iode == Raw->nav.eph[sat-1].iode)
return 0; /* unchanged */
}
eph.sat = sat;
Raw->nav.eph[sat-1] = eph;
Raw->ephsat = sat;
return 2;
#endif
}
/*
| DecodeGalileoEphemeris - Decode a Galileo Ephemeris record
|
| Returns:
|
| -1: error message
| 2: input ephemeris
|
| See reference #1 above for documentation of the RETSVDATA Galileo Ephemeris.
*/
static int DecodeGalileoEphemeris(raw_t *Raw)
{
tracet(3, "DecodeGalileoEphemeris(); not yet implemented.\n");
return 0;
#if 0
rt17_t *rt17 = (rt17_t*) Raw->rcv_data;
uint8_t *p = rt17->PacketBuffer;
int prn, sat, toc, tow;
uint32_t toe;
double sqrtA;
eph_t eph={0};
uint8_t SISA, MODEL1, MODEL2;
uint16_t IODnav, HSDVS;
double BDG1, BDG2;
tracet(3, "RT17: DecodeGalileoEphemeris(); Length=%d\n", rt17->PacketLength);
if (rt17->PacketLength < 190)
{
tracet(2, "RT17: RETSVDATA packet length %d < 190 bytes. Galileo ephemeris packet discarded.\n", rt17->PacketLength);
return -1;
}
prn = U1(p+5);
if (!(sat=satno(SYS_GAL, prn)))
{
tracet(2, "RT17: Galileo ephemeris satellite number error, PRN=%d.\n", prn);
return -1;
}
eph.code = U1(p+6); /* 006-006: Data source 0:E1B 1:E5B 2:E5A */
eph.week = U2(p+7); /* 007-008: Ephemeris Week number (weeks) */
tow = I4(p+9); /* 008-012: TOW */
IODnav = U2(p+13); /* 013-014: Ephemeris and clock correction issue of data */
toe = U4(p+15); /* 015-018: TOE (seconds) */
eph.crs = R8(p+19); /* 019-026: CRS (meters) */
eph.deln = R8(p+27); /* 027-034: DELTA N (semi-circles/second) */
eph.M0 = R8(p+35); /* 035-042: M SUB 0 (semi-circles) */
eph.cuc = R8(p+43); /* 043-050: CUC (semi-circles) */
eph.e = R8(p+51); /* 051-058: ECCENTRICITY (dimensionless) */
eph.cus = R8(p+59); /* 059-066: CUS (semi-circles) */
sqrtA = R8(p+67); /* 067-074: SQRT A (meters ^ 0.5) */
eph.cic = R8(p+75); /* 075-082: CIC (semi-circles) */
eph.OMG0 = R8(p+83); /* 083-090: OMEGA SUB 0 (semi-circles) */
eph.cis = R8(p+91); /* 091-098: CIS (semi-circlces) */
eph.i0 = R8(p+99); /* 099-106: I SUB 0 (semi-circles) */
eph.crc = R8(p+107); /* 107-114: CRC (meters) */
eph.omg = R8(p+115); /* 115-122: OMEGA (semi-circles?) */
eph.OMGd = R8(p+123); /* 123-130: OMEGA DOT (semi-circles/second) */
eph.idot = R8(p+131); /* 131-138: I DOT (semi-circles/second) */
SISA = U1(p+149); /* 149-149: ? */
HSDVS = U2(p+150); /* 150-151: Signal Health Flag */
toc = I4(p+142); /* 142-145: TOC (seconds) */
eph.f0 = R8(p+146); /* 146-153: AF0 (seconds) */
eph.f1 = R8(p+154); /* 154-161: AF1 (seconds/seconds) */
eph.f2 = R8(p+162); /* 162-169: AF2 (seconds/seconds^2) */
BDG1 = R8(p+170); /* 170-177: Seconds */
MODEL1 = U1(p+178); /* 178-178: Clock model for TOC/AF0?2/BGD1 */
BDG2 = R8(p+179); /* 179-186: Seconds */
MODEL2 = U1(p+187); /* 187-187: Clock model for BGD2 */
/*
| Multiply these by PI to make semi-circle units into radian units for RTKLIB.
*/
eph.deln *= SC2RAD;
eph.i0 *= SC2RAD;
eph.idot *= SC2RAD;
eph.M0 *= SC2RAD;
eph.omg *= SC2RAD;
eph.OMG0 *= SC2RAD;
eph.OMGd *= SC2RAD;
/*
| As specifically directed to do so by Reference #1, multiply these by PI.
| to make semi-circle units into radian units, which is what RTKLIB needs.
*/
eph.cic *= SC2RAD;
eph.cis *= SC2RAD;
eph.cuc *= SC2RAD;
eph.cus *= SC2RAD;
eph.A = sqrtA * sqrtA;
eph.toes = toe;
eph.toc = gst2time(eph.week, toc);
eph.toe = gst2time(eph.week, toe);
eph.ttr = gst2time(eph.week, tow);
tracet(3, "RT17: DecodeGalileoEphemeris(); SAT=%d, IODC=%d, IODE=%d, WEEK=%d.\n", sat, eph.iodc, eph.iode, eph.week);
if (!strstr(Raw->opt,"-EPHALL"))
{
if (eph.iode == Raw->nav.eph[sat-1].iode)
return 0; /* unchanged */
}
eph.sat = sat;
Raw->nav.eph[sat-1] = eph;
Raw->ephsat = sat;
return 2;
#endif
}
/*
| DecodeGLONASSEphemeris - Decode a GLONASS Ephemeris record
|
| Returns:
|
| -1: error message
| 2: input ephemeris
|
| See reference #1 above for documentation of the RETSVDATA GLONASS Ephemeris.
*/
static int DecodeGLONASSEphemeris(raw_t *Raw)
{
tracet(3, "DecodeGLONASSEphemeris(); not yet implemented.\n");
return 0;
}
/*
| DecodeGPSEphemeris - Decode a GPS Ephemeris record
|
| Returns:
|
| -1: error message
| 2: input ephemeris
|
| See ICD-GPS-200C.PDF for documentation of the GPS satellite ephemeris.
| See reference #1 above for documentation of the RETSVDATA GPS Ephemeris.
*/
static int DecodeGPSEphemeris(raw_t *Raw)
{
rt17_t *rt17 = (rt17_t*) Raw->rcv_data;
uint8_t *p = rt17->PacketBuffer;
int prn, sat, toc, tow;
uint32_t Flags, toe;
double sqrtA;
eph_t eph={0};
tracet(3, "RT17: DecodeGPSEphemeris(); Length=%d\n", rt17->PacketLength);
if (rt17->PacketLength < 182)
{
tracet(2, "RT17: RETSVDATA packet length %d < 182 bytes. GPS ephemeris packet discarded.\n", rt17->PacketLength);
return -1;
}
prn = U1(p+5);
if (!(sat=satno(SYS_GPS, prn)))
{
tracet(2, "RT17: GPS ephemeris satellite number error, PRN=%d.\n", prn);
return -1;
}
eph.week = U2(p+6); /* 006-007: Ephemeris Week number (weeks) */
eph.iodc = U2(p+8); /* 008-009: IODC */
/* Reserved byte */ /* 010-010: RESERVED */
eph.iode = U1(p+11); /* 011-011: IODE */
tow = I4(p+12); /* 012-015: TOW */
toc = I4(p+16); /* 016-019: TOC (seconds) */
toe = U4(p+20); /* 020-023: TOE (seconds) */
eph.tgd[0]= R8(p+24); /* 024-031: TGD (seconds) */
eph.f2 = R8(p+32); /* 032-029: AF2 (seconds/seconds^2) */
eph.f1 = R8(p+40); /* 040-047: AF1 (seconds/seconds) */
eph.f0 = R8(p+48); /* 048-055: AF0 (seconds) */
eph.crs = R8(p+56); /* 056-063: CRS (meters) */
eph.deln = R8(p+64); /* 064-071: DELTA N (semi-circles/second) */
eph.M0 = R8(p+72); /* 072-079: M SUB 0 (semi-circles) */
eph.cuc = R8(p+80); /* 080-087: CUC (semi-circles) */
eph.e = R8(p+88); /* 088-095: ECCENTRICITY (dimensionless) */
eph.cus = R8(p+96); /* 096-103: CUS (semi-circles) */
sqrtA = R8(p+104); /* 104-111: SQRT A (meters ^ 0.5) */
eph.cic = R8(p+112); /* 112-119: CIC (semi-circles) */
eph.OMG0 = R8(p+120); /* 120-127: OMEGA SUB 0 (semi-circles) */
eph.cis = R8(p+128); /* 128-135: CIS (semi-circlces) */
eph.i0 = R8(p+136); /* 136-143: I SUB 0 (semi-circles) */
eph.crc = R8(p+144); /* 144-151: CRC (meters) */
eph.omg = R8(p+152); /* 152-159: OMEGA (semi-circles?) */
eph.OMGd = R8(p+160); /* 160-167: OMEGA DOT (semi-circles/second) */
eph.idot = R8(p+168); /* 168-175: I DOT (semi-circles/second) */
Flags = U4(p+176); /* 176-179: FLAGS */
/*
| Multiply these by PI to make ICD specified semi-circle units into radian
| units for RTKLIB.
*/
eph.deln *= SC2RAD;
eph.i0 *= SC2RAD;
eph.idot *= SC2RAD;
eph.M0 *= SC2RAD;
eph.omg *= SC2RAD;
eph.OMG0 *= SC2RAD;
eph.OMGd *= SC2RAD;
/*
| As specifically directed to do so by Reference #1, multiply these by PI.
| to make semi-circle units into radian units, which is what ICD-GPS-200C
| calls for and also what RTKLIB needs.
*/
eph.cic *= SC2RAD;
eph.cis *= SC2RAD;
eph.cuc *= SC2RAD;
eph.cus *= SC2RAD;
/*
| Select the correct curve fit interval as per ICD-GPS-200 sections
| 20.3.3.4.3.1 and 20.3.4.4 using IODC, fit flag and Table 20-XII.
*/
if (Flags & M_BIT10) /* Subframe 2, word 10, bit 17 (fit flag) */
{
if ((eph.iodc >= 240) && (eph.iodc <= 247))
eph.fit = 8;
else if (((eph.iodc >= 248) && (eph.iodc <= 255)) || (eph.iodc == 496))
eph.fit = 14;
else if ((eph.iodc >= 497) && (eph.iodc <= 503))
eph.fit = 26;
else if ((eph.iodc >= 504) && (eph.iodc <= 510))
eph.fit = 50;
else if ((eph.iodc == 511) || ((eph.iodc >= 752) && (eph.iodc <= 756)))
eph.fit = 74;
else if ((eph.iodc >= 757) && (eph.iodc <= 763))
eph.fit = 98;
else if (((eph.iodc >= 764) && (eph.iodc <= 767)) || ((eph.iodc >= 1008) && (eph.iodc <= 1010)))
eph.fit = 122;
else if ((eph.iodc >= 1011) && (eph.iodc <= 1020))
eph.fit = 146;
else
eph.fit = 6;
}
else
eph.fit = 4;
eph.flag = (Flags & M_BIT0); /* Subframe 1, word 4, bit 1, Data flag for L2 P-code */
eph.code = (Flags >> 1) & 3; /* Subframe 1, word 3, bits 11-12, Codes on L2 channel */
eph.svh = (Flags >> 4) & 127; /* Subframe 1, word 3, bits 17-22, SV health from ephemeris */
eph.sva = (Flags >> 11) & 15; /* Subframe 1, word 3, bits 13-16, User Range Accuracy index */
eph.A = sqrtA * sqrtA;
eph.toes = toe;
eph.toc = gpst2time(eph.week, toc);
eph.toe = gpst2time(eph.week, toe);
eph.ttr = gpst2time(eph.week, tow);
tracet(3, "RT17: DecodeGPSEphemeris(); SAT=%d, IODC=%d, IODE=%d, WEEK=%d.\n", sat, eph.iodc, eph.iode, eph.week);
if (rt17->Week && (rt17->Week != eph.week))
{
tracet(2, "RT17: Currently set or assumed GPS week does not match received ephemeris week.\n");
tracet(2, "RT17: Set or assumed GPS week: %d Received ephemeris week: %d\n", rt17->Week, eph.week);
}
if (!(rt17->Flags & M_WEEK_OPTION))
{
if (!rt17->Week || (rt17->Flags & M_WEEK_TIME) || (eph.week > rt17->Week))
{
if (!rt17->Week)
tracet(2, "RT17: Initial GPS WEEK number unknown; WEEK number %d assumed for now.\n", eph.week);
else
tracet(2, "RT17: Changing assumed week number from %d to %d.\n", rt17->Week, eph.week);
rt17->Flags &= ~M_WEEK_TIME;
rt17->Flags |= M_WEEK_EPH;
rt17->Week = eph.week;
}
}
if (!strstr(Raw->opt,"-EPHALL"))
{
if (eph.iode == Raw->nav.eph[sat-1].iode)
return 0; /* unchanged */
}
eph.sat = sat;
Raw->nav.eph[sat-1] = eph;
Raw->ephsat = sat;
return 2;
}
/* DecodeGSOF - Decode a General Serial Output Format (GSOF) message */
static int DecodeGSOF(raw_t *Raw)
{
rt17_t *rt17 = (rt17_t*) Raw->rcv_data;
int InputLength, Ret = 0;
uint8_t RecordLength, RecordType, *p;
char *RecordType_s = NULL;
/*
| Reassemble origional message by removing packet headers,
| trailers and page framing.
*/
UnwrapGenout(rt17);
p = rt17->MessageBuffer;
InputLength = rt17->MessageLength;
while (InputLength)
{
RecordType = p[0];
RecordLength = p[1];
if (RecordType < (sizeof(GSOFTable) / sizeof(char*)))
RecordType_s = (char*) GSOFTable[RecordType];
if (!RecordType_s)
RecordType_s = "Unknown";
tracet(3, "RT17: Trimble packet type=0x40 (GENOUT), GSOF record type=%d (%s), Length=%d.\n", RecordType, RecordType_s, RecordLength);
/* Process (or possibly ignore) the message */
switch (RecordType)
{
case 1:
Ret = DecodeGSOF1(Raw, p);
break;
case 3:
Ret = DecodeGSOF3(Raw, p);
break;
case 15:
Ret = DecodeGSOF15(Raw, p);
break;
case 16:
Ret = DecodeGSOF16(Raw, p);
break;
case 26:
Ret = DecodeGSOF26(Raw, p);
break;
case 41:
Ret = DecodeGSOF41(Raw, p);
break;
default:
tracet(3, "RT17: GSOF message not processed.\n");
}
RecordLength += 2;
p += RecordLength;
InputLength -= RecordLength;
}
return Ret;
}
/* DecodeGSOF1 - Decode a Position Time GSOF message */
static int DecodeGSOF1(raw_t *Raw, uint8_t *p)
{
if (p[1] < 6)
tracet(2, "RT17: GSOF Position Time message record length %d < 6 bytes. Record discarded.\n", p[1]);
else
SetWeek(Raw, I2(p+6), ((double) I4(p+2)) * 0.001);
return 0;
}
/* DecodeGSOF3 - Decode an ECEF Position GSOF message */
static int DecodeGSOF3(raw_t *Raw, uint8_t *p)
{
sta_t *sta = &Raw->sta;
if (p[1] < 24)
tracet( 2, "RT17: GSOF ECEF Position record length %d < 24 bytes. Record discarded.\n", p[1] );
else
{
sta->pos[0] = R8(p+2);
sta->pos[1] = R8(p+10);
sta->pos[2] = R8(p+18);
sta->del[0] = 0.0;
sta->del[1] = 0.0;
sta->del[2] = 0.0;
sta->hgt = 0.0;
sta->deltype = 0; /* e/n/u */
}
return 5;
}
/* DecodeGSOF15 - Decode a Receiver Serial Number GSOF message */
static int DecodeGSOF15(raw_t *Raw, uint8_t *p)
{
if (p[1] < 15)
tracet(2, "RT17: GSOF Receiver Serial Number record length %d < 15 bytes. Record discarded.\n", p[1]);
else
sprintf(Raw->sta.recsno, "%u", U4(p+2));
return 0;
}
/* DecodeGSOF16 - Decode a Current Time GSOF message */
static int DecodeGSOF16(raw_t *Raw, uint8_t *p)
{
if (p[1] < 9)
tracet( 2, "RT17: GSOF Current Time message record length %d < 9 bytes. Record discarded.\n", p[1] );
else if (U1(p+10) & M_BIT0) /* If week and milliseconds of week are valid */
SetWeek(Raw, I2(p+6), ((double) I4(p+2)) * 0.001);
return 0;
}
/* DecodeGSOF26 - Decode a Position Time UTC GSOF message */
static int DecodeGSOF26(raw_t *Raw, uint8_t *p)
{
if (p[1] < 6)
tracet(2, "RT17: GSOF Position Time UTC message record length %d < 6 bytes. Record discarded.\n", p[1]);
else
SetWeek(Raw, I2(p+6), ((double) I4(p+2)) * 0.001);
return 0;
}
/* DecodeGSOF41 - Decode a Base Position and Quality Indicator GSOF message */
static int DecodeGSOF41(raw_t *raw, uint8_t *p)
{
if (p[1] < 6)
tracet(2, "RT17: GSOF Base Position and Quality Indicator message record length %d < 6 bytes. Record discarded.\n", p[1]);
else
SetWeek(raw, I2(p+6), ((double) I4(p+2)) * 0.001);
return 0;
}
/*
| DecodeIONAndUTCData - Decode an ION / UTC data record
|
| Returns:
|
| -1: error message
| 9: input ion/utc parameter|
|
| See ICD-GPS-200C.PDF for documetation of GPS ION / UTC data.
| See reference #1 above for documentation of RETSVDATA and ION / UTC data.
*/
static int DecodeIONAndUTCData(raw_t *Raw)
{
rt17_t *rt17 = (rt17_t*) Raw->rcv_data;
int week;
uint8_t *p = rt17->PacketBuffer;
nav_t *nav = &Raw->nav;
double *ion_gps = nav->ion_gps;
double *utc_gps = nav->utc_gps;
tracet(3, "RT17: DecodeIONAndUTCData, Length=%d.\n", rt17->PacketLength);
if (rt17->PacketLength < 129)
{
tracet(2, "RT17: RETSVDATA packet length %d < 129 bytes. GPS ION / UTC data packet discarded.\n", rt17->PacketLength);
return -1;
}
/* ION / UTC data does not have the current GPS week number. Punt! */
week = GetWeek(Raw, 0.0);
ion_gps[0] = R8(p+6); /* 006-013: ALPHA 0 (seconds) */
ion_gps[1] = R8(p+14); /* 014-021: ALPHA 1 (seconds/semi-circle) */
ion_gps[2] = R8(p+22); /* 022-029: ALPHA 2 (seconds/semi-circle)^2 */
ion_gps[3] = R8(p+30); /* 030-037: ALPHA 3 (seconds/semi-circle)^3 */
ion_gps[4] = R8(p+38); /* 038-045: BETA 0 (seconds) */
ion_gps[5] = R8(p+46); /* 046-053: BETA 1 (seconds/semi-circle) */
ion_gps[6] = R8(p+54); /* 054-061: BETA 2 (seconds/semi-circle)^2 */
ion_gps[7] = R8(p+62); /* 062-069: BETA 3 (seconds/semi-circle)^3 */
utc_gps[0] = R8(p+70); /* 070-077: ASUB0 (seconds)*/
utc_gps[1] = R8(p+78); /* 078-085: ASUB1 (seconds/seconds) */
utc_gps[2] = R8(p+86); /* 086-093: TSUB0T */
utc_gps[3] = week;
utc_gps[4] = R8(p+94); /* 094-101: DELTATLS (seconds) */
/* Unused by RTKLIB R8 */ /* 102-109: DELTATLSF */
/* Unused by RTKLIB R8 */ /* 110-117: IONTIME */
/* Unused by RTKLIB U1 */ /* 118-118: WNSUBT */
/* Unused by RTKLIB U1 */ /* 119-119: WNSUBLSF */
/* Unused by RTKLIB U1 */ /* 120-120: DN */
/* Reserved six bytes */ /* 121-126: RESERVED */
return 9;
}
/*
| DecodeQZSSEphemeris - Decode a QZSS Ephemeris record
|
| Returns:
|
| -1: error message
| 2: input ephemeris
|
| See reference #1 above for documentation of the RETSVDATA QZSS Ephemeris.
*/
static int DecodeQZSSEphemeris(raw_t *Raw)
{
tracet(3, "DecodeQZSSEphemeris(); not yet implemented.\n");
return 0;
#if 0
rt17_t *rt17 = (rt17_t*) Raw->rcv_data;
uint8_t *p = rt17->PacketBuffer;
int prn, sat, toc, tow;
uint32_t Flags, toe;
double sqrtA;
eph_t eph={0};
tracet(3, "RT17: DecodeQZSSEphemeris(); Length=%d\n", rt17->PacketLength);
if (rt17->PacketLength < 184)
{
tracet(2, "RT17: RETSVDATA packet length %d < 184 bytes. QZSS ephemeris packet discarded.\n", rt17->PacketLength);
return -1;
}
prn = U1(p+5);
if (!(sat=satno(SYS_GPS, prn)))
{
tracet(2, "RT17: QZSS ephemeris satellite number error, PRN=%d.\n", prn);
return -1;
}
/* Not used by RTKLIB 006-006: Source: 0:L1CA 1:L1C 2:L2C 3:L5 */
eph.week = U2(p+8); /* 008-009: Ephemeris Week number (weeks) */
eph.iodc = U2(p+10); /* 010-011: IODC */
/* Reserved byte 012-012: RESERVED */
eph.iode = U1(p+13); /* 013-013: IODE */
tow = I4(p+14); /* 014-017: TOW */
toc = I4(p+18); /* 018-021: TOC (seconds) */
toe = U4(p+22); /* 022-025: TOE (seconds) */
eph.tgd[0]= R8(p+26); /* 026-033: TGD (seconds) */
eph.f2 = R8(p+34); /* 034-041: AF2 (seconds/seconds^2) */
eph.f1 = R8(p+42); /* 042-049: AF1 (seconds/seconds) */
eph.f0 = R8(p+50); /* 050-057: AF0 (seconds) */
eph.crs = R8(p+58); /* 058-065: CRS (meters) */
eph.deln = R8(p+66); /* 066-073: DELTA N (semi-circles/second) */
eph.M0 = R8(p+74); /* 074-081: M SUB 0 (semi-circles) */
eph.cuc = R8(p+82); /* 082-089: CUC (semi-circles) */
eph.e = R8(p+90); /* 090-097: ECCENTRICITY (dimensionless) */
eph.cus = R8(p+98); /* 098-105: CUS (semi-circles) */
sqrtA = R8(p+106); /* 106-113: SQRT A (meters ^ 0.5) */
eph.cic = R8(p+114); /* 114-121: CIC (semi-circles) */
eph.OMG0 = R8(p+122); /* 122-129: OMEGA SUB 0 (semi-circles) */
eph.cis = R8(p+130); /* 130-137: CIS (semi-circlces) */
eph.i0 = R8(p+138); /* 138-145: I SUB 0 (semi-circles) */
eph.crc = R8(p+146); /* 146-153: CRC (meters) */
eph.omg = R8(p+154); /* 154-161: OMEGA (semi-circles?) */
eph.OMGd = R8(p+162); /* 162-169: OMEGA DOT (semi-circles/second) */
eph.idot = R8(p+170); /* 170-177: I DOT (semi-circles/second) */
Flags = U4(p+178); /* 178-181: FLAGS */
/*
| Multiply these by PI to make ICD specified semi-circle units into radian
| units for RTKLIB.
*/
eph.deln *= SC2RAD;
eph.i0 *= SC2RAD;
eph.idot *= SC2RAD;
eph.M0 *= SC2RAD;
eph.omg *= SC2RAD;
eph.OMG0 *= SC2RAD;
eph.OMGd *= SC2RAD;
/*
| As specifically directed to do so by Reference #1, multiply these by PI.
| to make semi-circle units into radian units, which is what ICD-GPS-200C
| calls for and also what RTKLIB needs.
*/
eph.cic *= SC2RAD;
eph.cis *= SC2RAD;
eph.cuc *= SC2RAD;
eph.cus *= SC2RAD;
/*
| Select the correct curve fit interval as per ICD-GPS-200 sections
| 20.3.3.4.3.1 and 20.3.4.4 using IODC, fit flag and Table 20-XII.
*/
if (Flags & M_BIT10) /* Subframe 2, word 10, bit 17 (fit flag) */
{
if ((eph.iodc >= 240) && (eph.iodc <= 247))
eph.fit = 8;
else if (((eph.iodc >= 248) && (eph.iodc <= 255)) || (eph.iodc == 496))
eph.fit = 14;
else if ((eph.iodc >= 497) && (eph.iodc <= 503))
eph.fit = 26;
else if ((eph.iodc >= 504) && (eph.iodc <= 510))
eph.fit = 50;
else if ((eph.iodc == 511) || ((eph.iodc >= 752) && (eph.iodc <= 756)))
eph.fit = 74;
else if ((eph.iodc >= 757) && (eph.iodc <= 763))
eph.fit = 98;
else if (((eph.iodc >= 764) && (eph.iodc <= 767)) || ((eph.iodc >= 1008) && (eph.iodc <= 1010)))
eph.fit = 122;
else if ((eph.iodc >= 1011) && (eph.iodc <= 1020))
eph.fit = 146;
else
eph.fit = 6;
}
else
eph.fit = 4;
eph.flag = (Flags & M_BIT0); /* Subframe 1, word 4, bit 1, Data flag for L2 P-code */
eph.code = (Flags >> 1) & 3; /* Subframe 1, word 3, bits 11-12, Codes on L2 channel */
eph.svh = (Flags >> 4) & 127; /* Subframe 1, word 3, bits 17-22, SV health from ephemeris */
eph.sva = (Flags >> 11) & 15; /* Subframe 1, word 3, bits 13-16, User Range Accuracy index */
eph.A = sqrtA * sqrtA;
eph.toes = toe;
eph.toc = gpst2time(eph.week, toc);
eph.toe = gpst2time(eph.week, toe);
eph.ttr = gpst2time(eph.week, tow);
tracet(3, "RT17: DecodeQZSSEphemeris(); SAT=%d, IODC=%d, IODE=%d, WEEK=%d.\n", sat, eph.iodc, eph.iode, eph.week);
if (!strstr(Raw->opt,"-EPHALL"))
{
if (eph.iode == Raw->nav.eph[sat-1].iode)
return 0; /* unchanged */
}
eph.sat = sat;
Raw->nav.eph[sat-1] = eph;
Raw->ephsat = sat;
return 2;
#endif
}
/*
| DecodeRawdata - Decode an RAWDATA packet sequence
|
| Returns:
|
| -1: error message
| 0: no message (tells caller to please read more data from the stream)
| 1: input observation data
*/
static int DecodeRawdata(raw_t *Raw)
{
rt17_t *rt17 = (rt17_t*) Raw->rcv_data;
uint8_t *MessageBuffer = rt17->MessageBuffer;
int Ret = 0;
uint32_t rif;
char *RecordType_s = NULL;
uint8_t RecordType = MessageBuffer[4];
if (RecordType < (sizeof(RawdataTable) / sizeof(char*)))
RecordType_s = (char*) RawdataTable[RecordType];
if (!RecordType_s)
RecordType_s = "Unknown";
tracet(3, "RT17: Trimble packet type=0x57 (RAWDATA), Recordtype=%d (%s), Length=%d.\n", RecordType, RecordType_s, rt17->MessageLength);
/*
| Reassemble origional message by removing packet headers,
| trailers and page framing.
*/
UnwrapRawdata(rt17, &rif);
/* Process (or possibly ignore) the message */
switch (RecordType)
{
case 0:
Ret = DecodeType17(Raw, rif);
break;
case 7:
Ret = DecodeType29(Raw);
break;
default:
tracet(3, "RT17: Packet not processed.\n");
}
return Ret;
}
/*
| DecodeRetsvdata - Decode an SVDATA packet
|
| Returns:
|
| -1: error message
| 0: no message (tells caller to please read more data from the stream)
| 2: input ephemeris
| 9: input ion/utc parameter
*/
static int DecodeRetsvdata(raw_t *Raw)
{
rt17_t *rt17 = (rt17_t*) Raw->rcv_data;
uint8_t *PacketBuffer = rt17->PacketBuffer;
int Ret = 0;
char *Subtype_s = NULL;
uint8_t Subtype = PacketBuffer[4];
if (Subtype < (sizeof(RetsvdataTable) / sizeof(char*)))
Subtype_s = (char*) RetsvdataTable[Subtype];
if (!Subtype_s)
Subtype_s = "Unknown";
tracet(3, "RT17: Trimble packet type=0x55 (RETSVDATA), Subtype=%d (%s), Length=%d.\n", Subtype, Subtype_s, rt17->PacketLength);
/* Process (or possibly ignore) the message */
switch (Subtype)
{
case 1:
Ret = DecodeGPSEphemeris(Raw);
break;
case 3:
Ret = DecodeIONAndUTCData(Raw);
break;
case 9:
Ret = DecodeGLONASSEphemeris(Raw);
break;
case 11:
Ret = DecodeGalileoEphemeris(Raw);
break;
case 14:
Ret = DecodeQZSSEphemeris(Raw);
break;
case 21:
Ret = DecodeBeidouEphemeris(Raw);
break;
default:
tracet(3, "RT17: Packet not processed.\n");
}
return Ret;
}
/*
| DecodeType17 - Decode Real-Time survey data (record type 17)
|
| Returns:
|
| -1: error message
| 0: no message (tells caller to please read more data from the stream)
| 1: input observation data
|
| Handles expanded and concise formats with and without enhanced record data.
*/
static int DecodeType17(raw_t *Raw, uint32_t rif)
{
rt17_t *rt17 = (rt17_t*) Raw->rcv_data;
uint8_t *p = rt17->MessageBuffer;
double ClockOffset, tow;
int Flags1, Flags2, FlagStatus, i, n, nsat, prn, Week;
gtime_t Time;
obsd_t *obs;
tow = R8(p) * 0.001; p += 8; /* Receive time within the current GPS week. */
ClockOffset = R8(p) * 0.001; p += 8; /* Clock offset value. 0.0 = not known */
#if 0
tow += ClockOffset;
#endif
/* The observation data does not have the current GPS week number. Punt! */
Week = GetWeek(Raw, tow);
Time = gpst2time(Week, tow);
nsat = U1(p); p++; /* Number of SV data blocks in the record */
for (i = n = 0; (i < nsat) && (i < MAXOBS); i++)
{
obs = &Raw->obs.data[n];
memset(obs, 0, sizeof(obsd_t));
obs->time = Time;
if (rif & M_CONCISE)
{
/* Satellite number (1-32). */
prn = U1(p);
p++;
/* These indicate what data is loaded, is valid, etc */
Flags1 = U1(p);
p++;
Flags2 = U1(p);
p++;
/* These are not needed by RTKLIB */
p++; /* I1 Satellite Elevation Angle (degrees) */
p += 2; /* I2 Satellite Azimuth (degrees) */
if (Flags1 & M_BIT6) /* L1 data valid */
{
/* Measure of L1 signal strength (dB * 4) */
obs->SNR[0] = (uint16_t)(U1(p)*0.25/SNR_UNIT+0.5);
p++;
/* Full L1 C/A code or P-code pseudorange (meters) */
obs->P[0] = R8(p);
p += 8;
/* L1 Continuous Phase (cycles) */
if (Flags1 & M_BIT4) /* L1 phase valid */
obs->L[0] = -R8(p);
p += 8;
/* L1 Doppler (Hz) */
obs->D[0] = R4(p);
p += 4;
}
if (Flags1 & M_BIT0) /* L2 data loaded */
{
/* Measure of L2 signal strength (dB * 4) */
obs->SNR[1] = (uint16_t)(U1(p)*0.25/SNR_UNIT+0.5);
p++;
/* L2 Continuous Phase (cycles) */
if (Flags1 & M_BIT5)
obs->L[1] = -R8(p);
p += 8;
/* L2 P-Code or L2 Encrypted Code */
if (Flags1 & M_BIT5) /* L2 range valid */
obs->P[1] = obs->P[0] + R4(p);
p += 4;
}
/*
| We can't use the IODE flags in this context.
| We already have slip flags and don't need slip counters.
*/
if (rif & M_ENHANCED)
{
p++; /* U1 IODE, Issue of Data Ephemeris */
p++; /* U1 L1 cycle slip roll-over counter */
p++; /* U1 L2 cycle slip roll-over counter */
}
}
else /* Expanded Format */
{
/* Satellite number (1-32) */
prn = U1(p);
p++;
/* These indicate what data is loaded, is valid, etc */
Flags1 = U1(p);
p++;
Flags2 = U1(p);
p++;
/* Indicates whether FLAGS1 bit 6 and FLAGS2 are valid */
FlagStatus = U1(p);
p++;
/* These are not needed by RTKLIB */
p += 2; /* I2 Satellite Elevation Angle (degrees) */
p += 2; /* I2 Satellite Azimuth (degrees) */
/*
| FLAG STATUS bit 0 set = Bit 6 of FLAGS1 and bit 0-7 of FLAGS2 are valid.
| FLAG STATUS bit 0 clear = Bit 6 of FLAGS1 and bit 0-7 of FLAGS2 are UNDEFINED.
|
| According to reference #1 above, this bit should ALWAYS be set
| for RAWDATA. If this bit is not set, then we're lost and cannot
| process this message any further.
*/
if (!(FlagStatus & M_BIT0)) /* Flags invalid */
return 0;
if (Flags1 & M_BIT6) /* L1 data valid */
{
/* Measure of satellite signal strength (dB) */
obs->SNR[0] = (uint16_t)(R8(p)/SNR_UNIT+0.5);
p += 8;
/* Full L1 C/A code or P-code pseudorange (meters) */
obs->P[0] = R8(p);
p += 8;
/* L1 Continuous Phase (cycles) */
if (Flags1 & M_BIT4) /* L1 phase valid */
obs->L[0] = -R8(p);
p += 8;
/* L1 Doppler (Hz) */
obs->D[0] = R8(p);
p += 8;
/* Reserved 8 bytes */
p += 8;
}
if (Flags1 & M_BIT0) /* L2 data loaded */
{
/* Measure of L2 signal strength (dB) */
obs->SNR[1] = (uint16_t)(R8(p)/SNR_UNIT+0.5);
p += 8;
/* L2 Continuous Phase (cycles) */
if (Flags1 & M_BIT5) /* L2 phase valid */
obs->L[1] = -R8(p);
p += 8;
/* L2 P-Code or L2 Encrypted Code */
if (Flags1 & M_BIT5) /* L2 pseudorange valid */
obs->P[1] = obs->P[0] + R8(p);
p += 8;
}
if (rif & M_ENHANCED)
{
/*
| We can't use the IODE flags in this context.
| We already have slip flags and don't need slip counters.
*/
p++; /* U1 IODE, Issue of Data Ephemeris */
p++; /* U1 L1 cycle slip roll-over counter */
p++; /* U1 L2 cycle slip roll-over counter */
p++; /* U1 Reserved byte */
/* L2 Doppler (Hz) */
obs->D[1] = R8(p);
p += 8;
}
}
obs->code[0] = (obs->P[0] == 0.0) ? CODE_NONE : (Flags2 & M_BIT0) ? CODE_L1P : CODE_L1C;
obs->code[1] = (obs->P[1] == 0.0) ? CODE_NONE : (Flags2 & M_BIT2) ? CODE_L2W : (Flags2 & M_BIT1) ? CODE_L2P : CODE_L2C;
if (Flags1 & M_BIT1)
obs->LLI[0] |= 1; /* L1 cycle slip */
if (Flags1 & M_BIT2)
obs->LLI[1] |= 1; /* L2 cycle slip */
if ((Flags2 & M_BIT2) && (obs->P[1] != 0.0))
obs->LLI[1] |= 4; /* Tracking encrypted code */
if (!(obs->sat = satno(SYS_GPS, prn)))
{
tracet(2, "RT17: Satellite number error, PRN=%d.\n", prn);
continue;
}
#if 0
/* Apply clock offset to observables */
if (ClockOffset != 0.0)
{
obs->P[0] += ClockOffset * (CLIGHT/FREQL1);
obs->P[1] += ClockOffset * (CLIGHT/FREQL2);
obs->L[0] += ClockOffset * FREQL1;
obs->L[1] += ClockOffset * FREQL2;
}
#endif
n++;
}
Raw->time = Time;
Raw->obs.n = n;
if (n > 0)
{
tracet(2, "RT17: Observations output:\n");
traceobs(2, Raw->obs.data, Raw->obs.n);
}
return (n > 0);
}
/* DecodeType29 - Decode Enhanced position (record type 29) */
static int DecodeType29(raw_t *Raw)
{
rt17_t *rt17 = (rt17_t*) Raw->rcv_data;
uint8_t *p = rt17->MessageBuffer;
if (*p < 7)
tracet(2, "RT17: Enhanced Position record block #1 length %d < 7 bytes. Record discarded.\n", *p);
else
SetWeek(Raw, I2(p+1), ((double) I4(p+3)) * 0.001);
return 0;
}
/*
| GetWeek - Get GPS week number
|
| Returns: GPS week number
|
| The -WEEK=n initial week option overrides everything else.
| Week rollover and increment from the initial week and
| subsequent weeks is handled.
*/
static int GetWeek(raw_t *Raw, double Tow)
{
rt17_t *rt17 = (rt17_t*) Raw->rcv_data;
int Week = 0;
if (rt17->Flags & M_WEEK_OPTION)
{
if ((Tow && rt17->Tow) && (Tow < rt17->Tow))
{
tracet(2, "RT17: GPS WEEK rolled over from %d to %d.\n", rt17->Week, rt17->Week + 1);
rt17->Week++;
}
if (Tow != 0.0)
rt17->Tow = Tow;
}
else if (!(rt17->Flags & M_WEEK_SCAN))
{
char *opt = strstr(Raw->opt, "-WEEK=");
rt17->Flags |= M_WEEK_SCAN;
if (opt)
{
if (!sscanf(opt+6, "%d", &Week) || (Week <= 0))
tracet(0, "RT17: Invalid -WEEK=n receiver option value.\n");
else
{
rt17->Week = Week;
rt17->Flags |= M_WEEK_OPTION;
tracet(2, "RT17: Initial GPS WEEK explicitly set to %d by user.\n", Week, Week);
}
}
}
Week = rt17->Week;
if (!Week && !(rt17->Flags & (M_WEEK_OPTION|M_WEEK_EPH)))
{
if ((Raw->time.time == 0) && (Raw->time.sec == 0.0))
Raw->time = timeget();
time2gpst(Raw->time, &Week);
if (Tow != 0.0)
Raw->time = gpst2time(Week, Tow);
rt17->Week = Week;
rt17->Flags |= M_WEEK_TIME;
tracet(2, "RT17: Initial GPS WEEK number unknown; WEEK number %d assumed for now.\n", Week);
}
return Week;
}
/* ReadI2 - Fetch & convert a signed two byte integer (short) */
static int16_t ReadI2(uint8_t *p)
{
union I2 {int16_t i2; uint8_t c[2];} u;
ENDIAN_TEST et;
memcpy(&u.i2, p, sizeof(u.i2));
et.u2 = 0; et.c[0] = 1;
if (et.u2 == 1)
{
uint8_t t;
t = u.c[0]; u.c[0] = u.c[1]; u.c[1] = t;
}
return u.i2;
}
/* ReadI4 - Fetch & convert a four byte signed integer (int) */
static int32_t ReadI4(uint8_t *p)
{
union i4 {int32_t i4; uint8_t c[4];} u;
ENDIAN_TEST et;
memcpy(&u.i4, p, sizeof(u.i4));
et.u2 = 0; et.c[0] = 1;
if (et.u2 == 1)
{
uint8_t t;
t = u.c[0]; u.c[0] = u.c[3]; u.c[3] = t;
t = u.c[1]; u.c[1] = u.c[2]; u.c[2] = t;
}
return u.i4;
}
/* ReadR4 - Fetch & convert an IEEE S_FLOAT (float) */
static float ReadR4(uint8_t *p)
{
union R4 {float f; uint32_t u4;} u;
u.u4 = U4(p);
return u.f;
}
/* ReadR8 - Fetch & convert an IEEE T_FLOAT (double) */
static double ReadR8(uint8_t *p)
{
ENDIAN_TEST et;
union R8 {double d; uint8_t c[8];} u;
memcpy(&u.d, p, sizeof(u.d));
et.u2 = 0; et.c[0] = 1;
if (et.u2 == 1)
{
uint8_t t;
t = u.c[0]; u.c[0] = u.c[7]; u.c[7] = t;
t = u.c[1]; u.c[1] = u.c[6]; u.c[6] = t;
t = u.c[2]; u.c[2] = u.c[5]; u.c[5] = t;
t = u.c[3]; u.c[3] = u.c[4]; u.c[4] = t;
}
return u.d;
}
/* ReadU2 - Fetch & convert an unsigned twe byte integer (uint16_t) */
static uint16_t ReadU2(uint8_t *p)
{
ENDIAN_TEST et;
union U2 {uint16_t u2; uint8_t c[2];} u;
memcpy(&u.u2, p, sizeof(u.u2));
et.u2 = 0; et.c[0] = 1;
if (et.u2 == 1)
{
uint8_t t;
t = u.c[0]; u.c[0] = u.c[1]; u.c[1] = t;
}
return u.u2;
}
/* ReadU4 - Fetch & convert a four byte uint32_teger (uint32_t) */
static uint32_t ReadU4(uint8_t *p)
{
ENDIAN_TEST et;
union U4 {uint32_t u4; uint8_t c[4];} u;
memcpy(&u.u4, p, sizeof(u.u4));
et.u2 = 0; et.c[0] = 1;
if (et.u2 == 1)
{
uint8_t t;
t = u.c[0]; u.c[0] = u.c[3]; u.c[3] = t;
t = u.c[1]; u.c[1] = u.c[2]; u.c[2] = t;
}
return u.u4;
}
/*
| SetWeek - Set GPS week number
|
| The -WEEK=n initial week option overrides us.
*/
static void SetWeek(raw_t *Raw, int Week, double Tow)
{
rt17_t *rt17 = (rt17_t*) Raw->rcv_data;
if (!(rt17->Flags & M_WEEK_OPTION))
{
if (rt17->Week)
{
if (Week != rt17->Week)
{
if (Week == (rt17->Week + 1))
tracet(2, "RT17: GPS WEEK rolled over from %d to %d.\n", rt17->Week, Week);
else
tracet(2, "RT17: GPS WEEK changed from %d to %d.\n", rt17->Week, Week);
}
}
else
tracet(2, "RT17: GPS WEEK initially set to %d.\n", Week);
rt17->Week = Week;
}
/* Also update the time if we can */
if (Week && (Tow != 0.0))
Raw->time = gpst2time(Week, Tow);
}
/* SyncPacket - Synchronize the raw data stream to the start of a series of RT-17 packets */
static int SyncPacket(rt17_t *rt17, uint8_t Data)
{
uint8_t Type, *PacketBuffer = rt17->PacketBuffer;
PacketBuffer[0] = PacketBuffer[1];
PacketBuffer[1] = PacketBuffer[2];
PacketBuffer[2] = PacketBuffer[3];
PacketBuffer[3] = Data;
Type = PacketBuffer[2];
/*
| Byte 0 must be an STX character.
| Byte 1 = status byte which we always ignore (for now).
| Byte 2 = packet type which must be GENOUT (0x40) RAWDATA (0x57) or RETSVDATA (0x55) (for now).
| Byte 3 = data length which must be non-zero for any packet we're interested in.
*/
return ((PacketBuffer[0] == STX) && (Data != 0) && ((Type == GENOUT) || (Type == RAWDATA) || (Type == RETSVDATA)));
}
/*
| UnwrapGenout - Reassemble GENOUT message by removing packet headers, trailers and page framing
|
| The GENOUT message is broken up on _arbitrary byte boundries_ into
| pages of no more than 246 bytes each, then wrapped with page frames,
| packet headers and packet trailers. We reassemble the original message
| so that it is uninterrupted by removing the extraneous packet headers,
| trailers and page framing.
*/
static void UnwrapGenout(rt17_t *rt17)
{
uint8_t *p_in = rt17->MessageBuffer;
uint8_t *p_out = p_in;
uint32_t InputLength, InputLengthTotal = rt17->MessageLength;
uint32_t OutputLength, OutputLengthTotal = 0;
while (InputLengthTotal > 0)
{
InputLength = p_in[3] + 6;
OutputLength = p_in[3] - 3;
memmove(p_out, p_in + 7, OutputLength);
p_in += InputLength;
p_out += OutputLength;
OutputLengthTotal += OutputLength;
InputLengthTotal -= InputLength;
}
rt17->MessageBytes = rt17->MessageLength = OutputLengthTotal;
}
/*
| UnwrapRawdata - Reassemble message by removing packet headers, trailers and page framing
|
| The RAWDATA message is broken up on _arbitrary byte boundries_ into
| pages of no more than 244 bytes each, then wrapped with page frames,
| packet headers and packet trailers. We reassemble the original message
| so that it is uninterrupted by removing the extraneous packet headers,
| trailers and page framing.
|
| While we're at it we also check to make sure the Record Interpretation
| Flags are consistent. They should be the same in every page frame.
*/
static void UnwrapRawdata(rt17_t *rt17, uint32_t *rif)
{
uint8_t *p_in = rt17->MessageBuffer;
uint8_t *p_out = p_in;
uint32_t InputLength, InputLengthTotal = rt17->MessageLength;
uint32_t OutputLength, OutputLengthTotal = 0;
*rif = p_in[7];
while (InputLengthTotal > 0)
{
if ((uint32_t)p_in[7] != *rif)
tracet(2, "RT17: Inconsistent Record Interpretation Flags within a single RAWDATA message.\n");
InputLength = p_in[3] + 6;
OutputLength = p_in[3] - 4;
memmove(p_out, p_in + 8, OutputLength);
p_in += InputLength;
p_out += OutputLength;
OutputLengthTotal += OutputLength;
InputLengthTotal -= InputLength;
}
rt17->MessageBytes = rt17->MessageLength = OutputLengthTotal;
}
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