In allusion to the short baseline in industry survey and relatively long baseline in engineering survey,combined with definite observation instrument and observation condition,the result of mean square error of a point is calculated,the precise and characteristic as well as application condition about four survey methods is contrasted and analyzed.

of the automatic height survey and positioning system based on horizontal radio platform for electrolysis anode.

In the long baseline multi-station time difference location system,the radiation source exists different flight speeds relative to the different stations,which results in the Doppler difference among the received signals from each station,therefore has an bad influence on the precise time delay measurement for the radiation source.

After a sufficient and necessary condition of phase interferometer unambiguous direction finding is proved,two methods of ambiguity resolution by combination of long baselines are presented.

The paper introduces Realization way of a long baseline acoustic positioning system for multi-targets, System have high resolution and flexible positioning way, can carry out real-time positioning, monitoring and management by map to multi-targets, The paper else introduces system’s design, component, key arithmetic way and test in sea.

However,the positioning accuracy is related to different errors because of the sparse distribution of reference points and GPS long base-line.

The long-short baselines and information of amplitude are employed to establish a method of setting stiding coarse phase according to the threshold of amplitude difference.