Under Antenna Reference Point for CORS info – To what is BPA referring?
For over 95% of the antennas in use for geodetic surveying, the BPA (Bottom of PreAmp) is the same as the ARP (Antenna Reference Point), or the bottom centermost point on the antenna, or where the tripod mounts to the antenna. All of our antenna calibrations are referenced to this point. For a list of antenna diagrams, see http://igscb.jpl.nasa.gov/igscb/station/general/antenna.gra . 49. What’s the story with AIS5 and 6? Is the problem with all of the U.S. Coast Guard sites? Which is the right station to use? Is the station currently operational? When will data be available for downloading for differential correction? To ensure safety of life operations, the US Coast Guard operates two independent sets of GPS equipment at each of its eighty-plus installations. The locations broadcast pseudorange correctors in real time for maritime navigation, but as a convenience also route GPS data to this agency for applications that correct the observables through post-processing methods. The two t
