Using antenna files for antenna calibrations

Default antenna information

The default antenna information is stored in the Trimble Common Files\IGSConfig folder (the default path is: C:\Program Files\Common Files\Trimble\IGSConfig). This folder contains a file called antennas.xml, which defines the antennas supported by Trimble software; and it contains at least two ANTEX (.atx) files, which provide absolute, elevation and azimuth dependent antenna corrections.

• IGS_antennas.atx provides the approved antenna corrections supplied by IGS.
• Trimble_antennas.atx at least provides two non-IGS antenna types (Unknown External and ADVNULLANTENNA), which can be used, if the actual antenna type is unknown. This may happen, when you insert station data from IGS site logs. Additionally, Trimble may provide new antenna calibrations, which have not yet been approved by IGS, using the Trimble_antennas.atx file.
• Providing individual antenna calibrations.

You may receive more antenna information from external sources. For example, you may have information about the calibration of your own antenna (depending on the individual antenna serial number). On the other hand, organizations such as NGS (U.S. National Geodetic Survey) or IFE (Institute for Geodesy) may have calibrated additional antenna types. For antenna types listed in the antennas.xml database file, Trimble 4D Control Server lets you provide individual calibrations so that information from special calibrations can be used for processing. To do so, the following is required:

• Make sure that the antenna calibration provides absolute antenna phase center corrections. Trimble 4D Control Server does not support relative calibrations.
• Store the antenna corrections in an ANTEX file with extension .atx.
• Provide an individual ANTEX file for each individual antenna. Trimble 4D Control Server accepts only one antenna calibration per file for individually calibrated antennas.
• Make sure that the antenna name in the ANTEX file completely matches the IGS conforming antenna name in the antennas.xml file.
• Store the ANTEX file in any folder at a computer contributing to the Trimble 4D Control Server system. However, be beware of the fact that the receiver module which will use this ANTEX file needs it at its local computer. Therefore, the file must reside there.
• Make the individual calibrations known to the system for the respective stations. Use the System Properties to access the Station Information. There, select Individually calibrated as antenna calibration type and specify the location of the ANTEX file.

Note - Trimble strongly recommends that you do not edit the default files in the IGSConfig folder.
During installation, updates, or automatic downloads, Trimble 4D Control Server checks whether the default files to be downloaded already exist and how old they are. If the local files are older than the files to be installed, they are automatically overwritten.
Individually created .atx files will be kept in any case. Nevertheless, Trimble recommends backing up your individually created files.