[00/04/20] The ant_info.003 antenna calibration file has been updated to include the following antennas: ASH701073.1, ASH701073.2, ASH701933B_M and ASH701945B_M.

[00/01/28] A new antenna information file (ant_info.003) is now available. This file conforms to the IGS naming standards as given in IGS file rcvr_ant.tab.
[99/09/30] Antenna calibration values and photos have been added for the ASHTECH 701945.02; the ASHTECH 701946.02; and the SPECTRA PRECISION 571908273, both with and without a radome.

[99/06/14] Antenna calibration values, photos and diagrams are availabe for the Leica AT502 antenna (LEIAT502).

[99/04/07] Antenna calibration values and photos are available for the Javad Regant dual depth choke ring antenna (JPSREGANT_DD_E).

[99/03/11] Trimble 33429.20 antenna calibration values, photos and engineering drawings are now available.

[99/03/19] Antenna calibration values and photos are available for the Javad Legant antenna on flat groundplane (JPSLEGANT_E) and for the Javad Regant single depth choke ring antenna (JPSREGANT_SD_E).

[99/03/11] Trimble 33429.20 antenna calibration values, photos and engineering drawings are now available.

[99/02/17] Trimble 4800 antenna calibration values, photos and engineering drawings are now available.

[99/02/17] Antenna calibration values and photos are available for the NovAtel GPS-501, GPS-502 and GPS-531. This includes those models both with and without choke rings. Engineering drawings for the GPS-502 and GPS-531 are also available.

[99/02/17] The antenna calibration values for the Leica AT504 antenna with choke ring are now available.

[99/02/17] Antenna calibration values and engineering drawings are available for the Javad "Legant" antenna.

[99/02/17] Engineering drawings are now available for most of the antennas listed at this web site.

[99/02/17] The antenna calibration results for the Trimble 4800, NovAtel GPS-501, Novatel GPS-502, NovAtel GPS-531, Leica AT504 and Javad Legant have been added to the Complete Antenna Calibration Results file.

[98/11/20] An updated version of the Antenna Calibration Results file is available. It now contains calibration results for the Ashtech 701008 antenna.

[98/10/29] An updated version of the Antenna Calibration Results file is now available.

[98/05/26] New measurements for the Leica AT202, AT302 and AT303 antennas have been completed and included in our results. Engineering drawings for these antennas are also now included.

[98/04/30] We have begun to add engineering drawings to the individual antenna pages. A new icon now appears next to the antenna photographs indicating whether or not a drawing is available. Click the icon to view the drawing. Copy the image if you like (gif format). The drawings also show the surface from which the NGS vertical offset measurements were made. Check the ASH 700718 or 700829 for an example. Other drawings will be added as they become available to us.

[98/04/30] The rms for the average offsets and pcv values included in these results has been added to the individual antenna pages. These rms values are non-zero whenever there have been at least 2 measurements of an antenna. These rms values are computed from the residuals to the average values as follows:
         rms = [ ( ( x - x' )2 / n ]1/2      

[98/04/30] This web site has been modified to include this window for news about changes or other developments concerning antenna calibrations. Viewer's comments are also welcome for inclusion. All previous news items will be saved and remain available.