The aviation gravimeter needs to work in constant temperature, and its working temperature is generally set at about 50℃. After all kinds of on-line normal, the gravimeter power heating, heating time is not less than 48 h, and in the subsequent measurement process to keep heating uninterrupted, until the completion of the entire measurement task.
During the heating process, some aviation gravimeters need to set the parameters step by step. For example, GT-1A aviation gravimeter needs to complete the following work (GT Company, 2006):
1) Measure the latitude, longitude and altitude of the GPS antenna of the airplane on the tarmac, and start powering up the heating.
2) The system automatically completes initialization.
3) Heating. Heating needs to complete the following tasks:
a Coordinate system calibration. Need to enter the latitude of the aircraft GPS antenna on the apron, enter the stored parameter data or manually enter these parameters.
b. Platform positioning.
c. Setting time parameters.
4) Automatic calibration. Obtain dp (drift of dynamically tuned gyro along the X-axis), dq (drift of dynamically tuned gyro along the Y-axis), dr (drift of fiber optic gyro along the Z-axis), Betz (offset of gravity sensor on the X-axis), Gamz (offset of gravity sensor on the Y-axis). It is also necessary to evaluate the results of the automatic calibration (as in Figure 6-5-1).
Figure 6-5-1 Auto-correction display results
5) Accuracy test. Simulate the flight measurement process to obtain the accuracy and drift amount of coarse and fine channels, and test the instrument.