Files needed of earths b arth fixed frame(not common Leap second table. Allows conversion from gPS time to UTC d in broadcast ephem Polar motion/uT1 earth-fixed orbits used not strictly necessary. Ocean tide loading model tables. Either in the form of station id that is 深 our averaged site:mmga would be expected 4/3003 12540Lec20 Files needed Antenna phase center model tables. Give the deviations of the phase as a function of elevation angle(and possibly azimuth) relative to a fixed point on the antenna(the ARP-antenna reference point). If the same type of antenna used in a small area, then not strictly needed but with mixed antenna types or large extent networks(such that satellites are seen at different elevation angles) then needed. May also need a file that translates names of antennas in rineX files into standard names(IGs maintains list of standard names for antennas)04/30/03 12.540 Lec 20 5 Files needed Needed for transforming orbits integrated in inertial space integrated in Earth fixed frame (not common). Allows conversion from GPS time to UTC. Offset included in broadcast ephemeris so not strictly needed if broadcast ephemeris used. Leap seconds are announced by the IERS Needed in the transformation from inertial to earth fixed frame. Available through the IERS. If earth-fixed orbits used not strictly necessary. Either in the form of station dependent values or in a grid that is interpolated. Recent addition. Signals are diurnal and semidiurnal mainly but alias through 24-hour averaged site positions more effectively than would be expected. 04/30/03 12.540 Lec 20 6 Files needed – Antenna phase center model tables. Give the deviations of the phase as a function of elevation angle (and possibly azimuth) relative to a fixed point on the antenna (the ARP-antenna reference point). If the same type of antenna used in a small area, then not strictly needed but with mixed antenna types or large extent networks (such that satellites are seen at different elevation angles) then needed. May also need a file that translates names of antennas in RINEX files into standard names (IGS maintains list of standard names for antennas). – Nutation tables: Give position of Earth’s body axis in space. back to Earth fixed frame or to compute the coriolis forces if – Leap second table. – Polar motion/UT1 tables. – Ocean tide loading model tables. 3