15 September 2010 ANTEX: The Antenna Exchange Format, Version 1.4 *********************************************** M. Rothacher, R. Schmid Forschungseinrichtung Satellitengeodäsie TU München 1. VERSION 1.4 MODIFICATIONS The modifications leading to Version 1.4 include: - integration of Compass, QZSS and SBAS (1.4) - definition of the Galileo satellite numbers (1.4) - IGS sorting convention (1.4) - definition of the frequency number codes (1.3) - clarification of the satellite-fixed coordinate system (1.3) - IGS naming convention (1.3) - definition of the antenna corrections (1.3) - optional SVN number and COSPAR ID (1.3) - optional serial number for reference antenna (1.2) - new calibration method ROBOT (1.2) - antenna-specific SINEX CODE (1.1) 2. FILE EXTENSION It is recommended to use 'atx' as file extension. For official IGS models the following naming convention is used: mmmmm_wwww.atx | | | +------- wwww: GPS week of the last file change | +------------ mmmmm: 5-character model name (will only be changed, if existing values are changed) For official IGS models the following sorting convention is applied: SATELLITE ANTENNAS: --> sorted by satellite system (GPS -> GLONASS -> Galileo -> Compass -> QZSS -> SBAS) --> sorted by satellite code "sNN" --> sorted by 'VALID FROM' RECEIVER ANTENNAS: --> sorted by antenna code --> sorted by radome code (NONE -> other radome types) --> sorted by 'SERIAL NO' 3. DEFINITION OF THE ANTENNA CORRECTIONS In order to clarify the sign convention, the following shortened formulae are given: RECEIVER ANTENNA: mean phase center position = ARP (antenna reference point) position + phase center offset vector (given in a topocentric left-handed system: north, east and up component) observed distance = geometric distance to the mean phase center + phase center variations (zenith, azimuth) + other corrections (Here the azimuth counts clockwise from the North toward the East.) SATELLITE ANTENNA: mean phase center position = CM (center of mass) position + phase center offset vector (The phase center offset is given in a satellite-fixed right-handed coordinate system: - z-axis points toward the geocenter - y-axis (rotation axis of the solar panels) corresponds to the cross product of the z-axis with the vector from the satellite to the Sun - x-axis completes the right-handed system (x cross y = z)) observed distance = geometric distance to the mean phase center + phase center variations (nadir, azimuth) + other corrections (Here the azimuth counts clockwise from the y-axis toward the x-axis when looking in the direction of the negative z-axis or toward deep space, respectively. For the estimation of the azimuth angle under which a station is seen from the satellite, the yaw attitude (rotation about the z-axis) has to be considered. Furthermore, deviations from the nominal attitude occur during eclipse seasons when the Sun sensors fail.) 4. ANTEX VERSION 1.4 FORMAT DEFINITIONS +--------------------+------------------------------------------+------------+ | HEADER LABEL | DESCRIPTION | FORMAT | | (Columns 61-80) | | | +--------------------+------------------------------------------+------------+ |ANTEX VERSION / SYST| - Format version (1.4) | F8.1,12X, | | | - Satellite system: 'G': GPS | A1,39X | | | 'R': GLONASS | | | | 'E': Galileo | | | | 'C': Compass | | | | 'J': QZSS | | | | 'S': SBAS | | | | 'M': Mixed | | +--------------------+------------------------------------------+------------+ |PCV TYPE / REFANT | - Phase center variation type: | A1,19X, | | | 'A': absolute values | | | | 'R': relative values | | | | - Reference antenna type for relative | A20, | | | values (blank: AOAD/M_T) | | | | - Serial number of the reference antenna | A20 | | | (optional) | | +--------------------+------------------------------------------+------------+ *|COMMENT | Comment line(s) | A60 |* | | (only allowed at the specified position) | | +--------------------+------------------------------------------+------------+ |END OF HEADER | Last record in the header section. | 60X | +--------------------+------------------------------------------+------------+ |START OF ANTENNA | Record indicating the start of an antenna| 60X | | | section. | | +--------------------+------------------------------------------+------------+ |TYPE / SERIAL NO | Receiver antenna: | | | | - Antenna type: strict IGS | A20, | | | rcvr_ant.tab antenna and radome code | | | | - Serial number (blank: all representa- | A20, | | | tives of the specified antenna type) | | | | - blank | A10, | | | - blank | A10 | | | Satellite antenna: | | | | - Antenna type: strict IGS | | | | rcvr_ant.tab satellite antenna code | | | | Example: 'BLOCK IIA' | | | | - Satellite code "sNN" (blank: all | | | | representatives of the specified | | | | antenna type) | | | | For the selection of single satellites| | | | the satellite system flag ('G','R', | | | | 'E','C','J','S') together with the PRN| | | | number (GPS, Compass), the slot number| | | | (GLONASS), the SVID number (Galileo), | | | | the 'PRN number minus 192' (QZSS) or | | | | the 'PRN number minus 100' (SBAS) has | | | | to be specified. | | | | Example: 'G05' | | | | - Satellite code "sNNN" (optional) | | | | s - satellite system flag | | | | NNN - SVN number (GPS), GLONASS | | | | number, GSAT number (Galileo) | | | | or SVN number (QZSS); blank | | | | (Compass, SBAS) | | | | - COSPAR ID "YYYY-XXXA" (optional) | | | | YYYY - year of when the launch vehicle| | | | was put in orbit | | | | XXX - sequential launch vehicle | | | | number for that year | | | | A - alpha numeric sequence number | | | | within a launch | | +--------------------+------------------------------------------+------------+ |METH / BY / # / DATE| - Calibration method: | A20, | | | 'CHAMBER', 'FIELD', 'ROBOT', | | | | 'COPIED' from other antenna, | | | | 'CONVERTED' from igs_01.pcv or blank | | | | - Name of agency | A20, | | | - Number of individual antennas | I6,4X, | | | calibrated | | | | - Date | A10 | +--------------------+------------------------------------------+------------+ |DAZI | Increment of the azimuth: | 2X,F6.1, | | | 0 to 360 with increment 'DAZI' | 52X | | | (in degrees). | | | | 360 degrees have to be divisible by | | | | 'DAZI'. | | | | Common value for 'DAZI': 5.0 | | | | For non-azimuth-dependent phase center | | | | variations '0.0' has to be specified. | | +--------------------+------------------------------------------+------------+ |ZEN1 / ZEN2 / DZEN | Receiver antenna: | 2X,3F6.1, | | | Definition of the grid in zenith | 40X | | | angle: | | | | Zenith distance 'ZEN1' to 'ZEN2' with | | | | increment 'DZEN' (in degrees). 'DZEN' | | | | has to be > 0.0. | | | | 'ZEN1' and 'ZEN2' always have to be | | | | multiples of 'DZEN'. | | | | 'ZEN2' always has to be greater than | | | | 'ZEN1'. | | | | Common value for 'DZEN': 5.0 | | | | Example: ' 0.0 90.0 5.0' | | | | Satellite antenna: | | | | Definition of the grid in nadir | | | | angle: | | | | Nadir angle 'ZEN1' to 'ZEN2' with | | | | increment 'DZEN' (in degrees). 'DZEN' | | | | has to be > 0.0. | | | | 'ZEN1' and 'ZEN2' always have to be | | | | multiples of 'DZEN'. | | | | 'ZEN2' always has to be greater than | | | | 'ZEN1'. | | | | Common value for 'DZEN': 1.0 | | | | Example: ' 0.0 14.0 1.0' | | +--------------------+------------------------------------------+------------+ |# OF FREQUENCIES | Number of frequencies, for which phase | I6,54X | | | patterns are stored for the current | | | | antenna. | | +--------------------+------------------------------------------+------------+ *|VALID FROM | Start of validity period in GPS time | 5I6,F13.7, |* | | (4-digit year, month, day, hour, min, | 17X | | | sec) | | +--------------------+------------------------------------------+------------+ *|VALID UNTIL | End of validity period in GPS time | 5I6,F13.7, |* | | (4-digit year, month, day, hour, min, | 17X | | | sec) | | +--------------------+------------------------------------------+------------+ *|SINEX CODE | Name of the antenna calibration model to | A10,50X |* | | be used in the SINEX format (for | | | | referencing purposes) | | +--------------------+------------------------------------------+------------+ *|COMMENT | Comment line(s) | A60 |* | | (only allowed at the specified position) | | +--------------------+------------------------------------------+------------+ |START OF FREQUENCY | Record indicating the start of a new |3X,A1,I2,54X| | | frequency section. The satellite system | | | | flag ('G','R','E','C','J','S') has to be | | | | specified together with the frequency | | | | number code that has to be consistent | | | | with the RINEX definition: | | | | GPS: 'G01' - L1 | | | | 'G02' - L2 | | | | 'G05' - L5 | | | | GLONASS: 'R01' - G1 | | | | 'R02' - G2 | | | | Galileo: 'E01' - E1 | | | | 'E05' - E5a | | | | 'E07' - E5b | | | | 'E08' - E5 (E5a+E5b) | | | | 'E06' - E6 | | | | Compass: 'C01' - E1 | | | | 'C02' - E2 | | | | 'C07' - E5b | | | | 'C06' - E6 | | | | QZSS: 'J01' - L1 | | | | 'J02' - L2 | | | | 'J05' - L5 | | | | 'J06' - LEX | | | | SBAS: 'S01' - L1 | | | | 'S05' - L5 | | | | The frequency section includes the | | | | eccentricities of the mean antenna phase | | | | center and the phase pattern values. | | | | Neither other types of records nor | | | | comment lines are allowed within this | | | | section. | | +--------------------+------------------------------------------+------------+ |NORTH / EAST / UP | Receiver antenna: | 3F10.2,30X | | | Eccentricities of the mean antenna phase| | | | center relative to the antenna reference| | | | point (ARP). North, east and up | | | | component (in millimeters). | | | | Satellite antenna: | | | | Eccentricities of the mean antenna phase| | | | center relative to the center of mass of| | | | the satellite in X-, Y- and Z-direction | | | | (in millimeters). | | +--------------------+------------------------------------------+------------+ |(Values of a non- | The flag 'NOAZI' denotes a non-azimuth- | 3X,A5,mF8.2| |azimuth-dependent | dependent pattern that has to be | | |pattern) | specified in any case (also if 'DAZI' > | | | | 0.0). | | | | Phase pattern values in millimeters from | | | | 'ZEN1' to 'ZEN2' (with increment 'DZEN').| | | | All values on one line. | | +--------------------+------------------------------------------+------------+ *|(Values of an | The azimuth-dependent pattern has to be | F8.1,mF8.2 |* |azimuth-dependent | specified, if 'DAZI' > 0.0. The first | | |pattern) | value in each line denotes the azimuth | | | | angle followed by the phase pattern | | | | values in millimeters from 'ZEN1' to | | | | 'ZEN2' (with increment 'DZEN'). | | | | All values of one azimuth angle on one | | | | line. | | +--------------------+------------------------------------------+------------+ |END OF FREQUENCY | Record indicating the end of a frequency |3X,A1,I2,54X| | | section (see also 'START OF FREQUENCY'). | | +--------------------+------------------------------------------+------------+ *|START OF FREQ RMS | Record indicating the start of an rms |3X,A1,I2,54X|* | | value section related to the specified | | | | frequency. | | | | The section includes the rms values of | | | | the phase center eccentricities and of | | | | the phase pattern values. | | | | Neither other types of records nor | | | | comment lines are allowed within this | | | | section. | | +--------------------+------------------------------------------+------------+ *|NORTH / EAST / UP | Rms of the eccentricities (in milli- | 3F10.2,30X |* | | meters). | | +--------------------+------------------------------------------+------------+ *|(Rms values of the | The flag 'NOAZI' denotes the rms values | 3X,A5,mF8.2|* |non-azimuth- | of the non-azimuth-dependent pattern. | | |dependent pattern) | Phase pattern rms values in millimeters | | | | from 'ZEN1' to 'ZEN2' (with increment | | | | 'DZEN'). | | | | All values on one line. | | +--------------------+------------------------------------------+------------+ *|(Rms values of the | Rms values of the azimuth-dependent | F8.1,mF8.2 |* |azimuth-dependent | pattern, if 'DAZI' > 0.0. The first | | |pattern) | value in each line denotes the azimuth | | | | angle followed by the phase pattern rms | | | | values in millimeters from 'ZEN1' to | | | | 'ZEN2' (with increment 'DZEN'). | | | | All values of one azimuth angle on one | | | | line. | | +--------------------+------------------------------------------+------------+ *|END OF FREQ RMS | Record indicating the end of an rms value|3X,A1,I2,54X|* | | section (see also 'START OF FREQ RMS'). | | +--------------------+------------------------------------------+------------+ |END OF ANTENNA | Record indicating the end of an antenna | 60X | | | section. | | +--------------------+------------------------------------------+------------+ Records marked with * are optional 5. COMMENTS - For information on GPS satellites (SVN, PRN, etc.) please refer to ftp://tycho.usno.navy.mil/pub/gps/gpsb1.txt and ftp://tycho.usno.navy.mil/pub/gps/gpsb2.txt or http://gge.unb.ca/Resources/GPSConstellationStatus.txt - For information on GLONASS satellites (GLONASS number, slot number, etc.) please refer to http://www.glonass-ianc.rsa.ru/ or http://gge.unb.ca/Resources/GLONASSConstellationStatus.txt or http://web.archive.org/web/20060304211606/http://www.glonass-center.ru/hist_e.html - For information on Compass satellites please refer to http://www.beidou.gov.cn/ - For information on QZSS satellites (PRN, etc.) please refer to http://qzss.jaxa.jp/is-qzss/IS-QZSS_11_E.pdf or http://www.losangeles.af.mil/library/factsheets/factsheet.asp?id=8618 - For information on SBAS satellites (PRN, etc.) please refer to http://www.losangeles.af.mil/library/factsheets/factsheet.asp?id=8618 - For COSPAR IDs please refer to http://nssdc.gsfc.nasa.gov/nmc/SpacecraftQuery.jsp or http://ilrs.gsfc.nasa.gov/satellite_missions/list_of_satellites/gl40_general.html - For IGS standard antenna names please refer to ftp://igs.org/igscb/station/general/rcvr_ant.tab - For further antenna calibration results please refer to http://www.ngs.noaa.gov/ANTCAL/ or http://gnpcvdb.geopp.de/ 6. REFERENCES Rothacher, M., Mader, G. (2003): "Receiver and satellite antenna phase center offsets and variations." In: Tétreault, P., Neilan, R., Gowey, K. (eds.) Proceedings of the Network, Data and Analysis Centre 2002 Workshop, pp. 141-152, Ottawa. (http://igs.org/igscb/resource/pubs/02_ott/session_8.pdf) Schmid, R., Mader, G., Herring, T. (2005): "From relative to absolute antenna phase center corrections." In: Meindl, M. (ed.) Proceedings of the IGS Workshop and Symposium 2004, Bern. (http://igs.org/igscb/resource/pubs/04_rtberne/Session10_1.pdf)