Background gap, seismogenic gap and approaching shock before Boketu and Dedu moderate earthquake occurred on Feb.

Some results are as follows:① A background gap of M≥5.

Theoretical methods of improving the performance of dim-point target recognition under sea and sky background;

By analyzing the character of IR image and the rules about IR radiation of the objects in sky background,this paper presents the way to compose and display the real time IR back-ground image of antiaircraft missile.

Research on image sequence compression method of celestial background;

Followed,based on the IR catalogue data,an approach for modelling the celestial background observed in any time,on any eyeshot and at any visual angel,is presented.

Based on the catalogue data, it is presented an approach for modeling and simulating the celestial background observed in any time and at any places.

Research on real-time dim target detection algorithm in deep space;

From the spatio-temporal background of evolvement of Northeast China, this paper analyses the characteristics and its cause of formation and discusses and probes into the flourishing guidelines and strategy.