Sea surface temperature (SST) is an important factor that affects the changes of marine fishery resources. In this paper, the characteristics of distribution and variation in sea surface temperature was retrieved in northwestern Pacific Ocean by MODIS from 2008 to 2017. The results showed that the distribution of SST in northwestern Pacific Ocean was found to be characterized by regional and seasonal changes. Annually, periodical changes in SST was found unconspicuously, and spatially, the SST high value area showed a trend of moving from high-latitude to low-latitude. In August each year, there seemed to be a temperature boundary at 40°N, and the boundary will move south in September. Finally, we analyzed the SST distribution of the two main fishing periods of <i>Cololabis saira </i>in August and September each year, and preliminarily explained the cause of the "fish shortage" of saury recently years in Japan. The long-term variations in SST were discussed macroscopically in this paper, and this could give a new insight into fishing industry research in the Northwest Pacific.
The 3D model is an important part of simulated remote sensing for earth observation. Regarding the small-scale spatial extent of DART software, both the details of the model itself and the number of models of the distribution have an important impact on the scene canopy Normalized Difference Vegetation Index (NDVI).Taking the phragmitesaustralis in the Yangtze Estuary as an example, this paper studied the effect of the P.australias model on the canopy NDVI, based on the previous studies of the model precision, mainly from the cell dimension of the DART software and the density distribution of the P.australias model in the scene, As well as the choice of the density of the P.australiass model under the cost of computer running time in the actual simulation. The DART Cell dimensions and the density of the scene model were set by using the optimal precision model from the existing research results. The simulation results of NDVI with different model densities under different cell dimensions were analyzed by error analysis. By studying the relationship between relative error, absolute error and time costs, we have mastered the density selection method of P.australias model in the simulation of small-scale spatial scale scene. Experiments showed that the number of P.australias in the simulated scene need not be the same as those in the real environment due to the difference between the 3D model and the real scenarios. The best simulation results could be obtained by keeping the density ratio of about 40 trees per square meter, simultaneously, of the visual effects.