GPS data Map matching based on ArcGIS

GPS data due to bad signal, communication anomalies, positioning errors and other reasons, can not fall well on the road, so need to map GPS data to match, and the road associated. Because of its special data format, spatial data is still the best way to handle the ArcGIS Desktop series software.

First, road network data inspection

According to the needs of the experiment, the network data is extracted, the topology of the network is checked, including no overlap, no hanging points, etc., and the topological errors are modified; At the same time, the "interrupt at Vertex" operation is required to form the correct network data.

second, GPS data inspection

GPS data preprocessing is the first step in the use of GPS data, see blog.

third, map matching

1. GPS Data Extraction

Existing GPS data is generated by taxis running in cities, and data update issues need to be considered before matching GPS points to road network data: Cities change every day, road networks change every day, and GPS data may contain roads that do not exist in existing road networks, so it leads to " The topic of road updating based on GPS data "1. Since this experiment focuses on the existing road network, it is first to extract the GPS data associated with the existing roads.

#coding: Utf-8Importarcpy fromarcpyImportEnvenv.workspace =R ' F:\GraduateStudy\Graduate\Data\Scratch.gdb '#做缓冲区Print ' Buffer 'Buffer = arcpy. Buffer_analysis (' Road ',' # ',' Meters ',' Full ',' ROUND ',' All ',' # ',' PLANAR ') buffer = Buffer.getoutput (0)#buffer的路径Buffer_name = Buffer.split (' \ \ ')[-1]#缓冲区与GPS数据相交Print ' Intersect 'Gps_intersect = arcpy. Intersect_analysis (' GPS20121114 #; '+ Buffer_name +' # ',' # ',' All ',' # ',' INPUT ') Gps_intersect = Gps_intersect.getoutput (0)#相交后GPS数据的路径Gps_intersect_name = Gps_intersect.split (' \ \ ')[-1]

The buffer buffer analysis is done on the road, and the resulting buffers are fused (otherwise there will be duplicate parts, making the GPS point overlap when cutting). According to the accuracy of GPs points in the experiment, the network is done 20 meters buffer.

The GPS points intersect with buffer to get GPS data in the range of the existing network.

2. Selection of matching index

The selection of matching degree index is the most important link in map matching, and it directly determines the matching effect. In general, the matching of points and lines takes into account both distance and direction factors. Distance factor considerations from needless to say, within a certain distance, there are many possible sections of the premise, you need to consider which road and GPs point direction closest. The matching degree is calculated as:
In ArcGIS, you can use "neighbor analysis" to calculate the distance between the GPS point and each candidate road segment, with the north as 0°, clockwise rotation, the unified construction of the angle measure, calculates the angle between the GPS point direction and each candidate road, the final calculation to obtain the matching degree.

3. Use the method of updating geometry to move the GPS point to the road.

#GPS数据, to the road network, to do near-neighbor analysisarcpy. Near_analysis (Gps_intersect_name, Road_name,' # ',' Location ',' No_angle ',' PLANAR ') field_x =' near_x 'Field_y =' near_y '#对每一条GPS数据提取地图匹配后的位置DIC = {}cursor = Arcpy.da.SearchCursor (Gps_intersect_name, [' OBJECTID ',' near_x ',' near_y ']) forRowinchcursor:dic[row[0]] = [row[1],row[2]]delCursordelRow#更新几何cursor = Arcpy.da.UpdateCursor (gps_intersect_name,[' OBJECTID ',' [email protected] ']) forRowinchcursor:row[1] = dic[row[0]] Cursor.updaterow (ROW)delCursordelRow

written in the last

The research of map matching algorithm is not a new problem, a large number of scholars to improve the map matching algorithm 2, this article is only one of the simplest geometric matching, and in practice, taking into account the data inconsistency, the purpose of map matching, and other specific problems, everyone's methods are not the same. Hope the method of this article can help, welcome a lot of exchange advice.

(by Mrhammer 2016-05-08 3 o'clock in the afternoon @Bin house Rainy)

1. Http://www.cnki.net/KCMS/detail/detail.aspx? Queryid=1&currec=6&recid=&filename=1014356141.nh&dbname=cmfd201501&dbcode=cmfd&pr= &urlid=&yx=&v= Mdg5ndiynkdyqzlhtkrjcnbfylbjujhlwdfmdxhzuzdeadfum3fucldnmuzyq1vsthlmwxvabkz5m25vynpcvky=?
2. Http://www.cnki.net/KCMS/detail/detail.aspx? queryid=1&currec=1&recid=&filename=chxb201201026&dbname=cjfd2012&dbcode=cjfq&pr=& Urlid=&yx=&v=mjyxntr6z1u3ek9kavhuykxhneg5ue1ybzliww9sogvymux1efltn0romvqzcvryv00xrnjdvvjmewzzdvpurnk=?

GPS data Map matching based on ArcGIS