The BEST logs output the best solution of RTK, PSR, Omnistar, INS, Etc The BESTGPS logs output the same types except it never switches to the INS solution, it always shows the best GPS solution. The INS position types used in the BEST logs attempt to inform the user that they are getting an INS solution, but that the INS solution has been updated with a GPS position of type XXXX. For example INS_RTK_FIXED means the solution output is from the INS filter, but the INS Filter has been updated with a fixed integer RTK solution. The INS logs output the solution from the INS filter (similarly, the RTKPOS log outputs the solution from the RTK filter), but don't give any information about the quality of the GPS. For this reason we added the BESTGPS logs, which give the best GPS solution and give the user a way to monitor the status of the GPS independently of the INS solution. Alternatively, the INSUPDATE log gives the kalman filter update status for the INS filter. It gives the status of the GPS that was last used to update the INS filter Here are the INS Calculated Position or Velocity Types: Type(Binary) Description INS(52) INS calculated position corrected for the antenna INS_PSRSP(53) INS pseudorange single point solution - no DGPS corrections INS_PSRDIFF(54) INS pseudorange differential solution INS_RTKFLOAT(55) INS RTK floating point ambiguities solution INS_RTKFIXED(56) INS RTK fixed ambiguities solution Here are INS Solution Status Values: Solution Status(Binary) Description INS_INACTIVE(14) INS has not started yet INS_ALIGNING(15) INS doing its coarse alignment INS_BAD(16) INS position is bad IMU_UNPLUGGED(17) No IMU detected Here are INS Status Definitions: Status(Binary) Description INS_INACTIVE(0) INS is inactive INS_ALIGNING(1) INS is aligning INS_SOLUTION_NOT_GOOD(2) INS solution is not good INS_SOLUTION_GOOD(3) INS solution is good INS_TEST_ALIGNING(4) INS test is aligning INS_TEST_SOLUTION_GOOD(5) INS test solution is good INS_BAD_GPS_AGREEMENT(6) GSP agreement is good but the INS solution is bad INS_ALIGNMENT_COMPLETE (7) The state immediately after the alignment is finished but before enough velocity has been observed for the attitude, specifically azimuth, to become converged.