Research on the node location algorithm in the wireless sensor network

In the wireless sensor network, many applications need to known the location of the node, so node location technology is key technology and research hot spot in WSN . Although the trilateral measuring method which has been given just need to know the coordinate of three beacon nodes, and the distance between beacon nodes and unknown nodes, then you can calculate the unknown nodes´ coordinates, But in the practical application, due to measurement errors, makes the distance between unknown nodes and three beacon nodes be not accurate, causing there is no solution in the equations of problem. Therefore, this article will introduce the centroid location algorithm thought into the trilateral measuring method, improve the trilateral measurement method, and put forward the trilateral centroid localization algorithm. By calculating the intersection of the intersected round and the center in the area of intersection to estimate unknown nodes, making the unknown nodes coordinates estimated is more accurate.