It deduces the type of prism eccentricity, analyzes the precision influence of eccentricity on the digital map, derives the mathematical model of the eccentricity correction for the coordinate data .

This paper discusses that the theory of eccentricity correction for road as follows: after coordinate transformation has been completed,we approach real orbits through all collection points of sideline by cubic spline,then carry on eccentricity correction to get coordinates of point corresponding to those collection points of sideline.

The rule of variation of residual paleomagnetic declination by the drift of lithospheric plate.;

Because there is no orientation line in many seismic stations, people has to use the compass to find the earth’s north orientation and use the magnetic declination to correct the result.

<Abstrcat>From August, 2003, the changes in magnetic declination of relative observation are large than that before at Mengcheng magnetic station.

A method of automatically computing magnetic declination via the geomagnetic declination map;

The scheme uses geomagnetic declination and geomagnetic inclination as matching parameters to acquire rough position.

Based on the research on sensitivity of geomagnetic declination on wind measurement by UAV(unmanned aerial vehicle) with Pitot-static tube,mathematical model of wind speed error to effect of geomagnetic declination is set up in virtue of wind measurement theory and error theory.