Equipment accepted within the EPN
The GNSS equipment used at the EPN stations complies with the
This means that :
- the GNSS receiver and antenna must be known to the IGS and included in the receiver/antenna table
(rcvr_ant.tab file). This table contains the IGS/EPN naming conventions
for GNSS equipment (receivers, antennas, radomes, satellite antennas); they are the only valid names to be used in IGS station logs,
RINEX headers, SINEX files, etc. Checklist for including new entries in rcvr_ant.tab.
A description of the antenna (physical dimensions and antenna reference point (ARP) definition) is given in the antenna.gra file.
- the receiver and antenna should at least allow dual frequency geodetic-type GNSS observations.
- the antenna+radome pair should have zenith and azimuth-dependent absolute calibration values down to the horizon available from the EPN Central Bureau
(antenna/radomes fulfilling this requirement).
The usage of antenna radomes is discouraged, but not forbidden.
Antenna/radome calibrations used by the EPN
The antenna calibrations used within the EPN are given in the epn_08.atx file (in usage since April 17, 2011),
available in the standard format used to exchange antenna calibrations, the ANTEX format.
This file contains :
- The individual antenna calibrations used within the EPN, available from the EPN CB, and given in the file
epnc_08.atx. For more details, see
EUREF mail 3020.
- The antenna calibration values used within the IGS, available from the IGS Central Bureau, and given in
the igs08.atx file (linking to the
file igs08_wwww.atx, with wwww the GPS week of the last file change).
Type calibration values are applied in case no individual absolute calibrations are available. If no individual nor type calibrations are available
for a specific antenna+radome combination, then the calibrations for the
corresponding antenna without a radome (radome code: NONE) should be applied.
The map below shows for each EPN station what kind of absolute
antenna/radome calibrations are available:
- black: antenna/radome pairs with absolute individual calibrations (15.98%)
- green: antenna/radome pairs with true absolute type calibrations (69.26%)
- orange: antenna/radome pairs with absolute calibrations converted from relative values (6.56%)
- red: antenna/radome pairs without absolute calibrations. In this case, the radome is neglected and the calibration values of the antenna with radome 'NONE' is used (8.20%)
The long-term goal of EUREF is to eliminate the red and yellow dots from
this map and to have a network with antenna+radome equipment which all
have true absolute ('individual' or 'type') calibrations freely
available from the EPN Central Bureau. To achieve this goal, new
antenna+radome pairs introduced in the EPN (new stations or replacements
at existing stations) should, with some exceptions, be individually
calibrated or have true absolute calibrations available from the IGS.
More details are available in
"Procedure for Becoming an EPN Station"
"Guidelines for EPN Stations and Operational Centres".
Where to go for individual antenna calibrations?
The following agencies/firms offer the individual absolute calibration of GNSS antenna/radome pairs :
- meeting the current IGS requirements for receiver antenna calibrations: