The distribution patterns of community biomasses were studied on the two kinds of ecotones between forests and swamps in the Mudanjiang forest region by using transect and model method, In order to understand the growing laws of the dominant tree species, and the distribution patterns of community biomasses along the hydrological environmental gradients or along vertical story of communities.

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.