GPS轨迹纠偏算法，java代码，包含异常点检测、滤波平滑，

package com.example.trace; import android.util.Log; import java.util.ArrayList; import java.util.List; /** * GPS轨迹异常点检测与处理 */ public class Outlier { public static float state; //判断巡河员巡河方式 public static void checkState(ArrayList<double[]> gpsList) { double[] dangerBefore = null; double distance = 0; for (int i = 1; i < gpsList.size(); i++) { double[] dangerVo = gpsList.get(i); if (dangerBefore == null) { dangerBefore = gpsList.get(i - 1); } distance += LocationConvert.getDistance(dangerVo[0], dangerVo[1], dangerBefore[0], dangerBefore[1]); dangerBefore = dangerVo; } double disAvg = distance / (gpsList.size() - 1); // Log.i("safe", "总距离dis: " + distance+" disavg: "+disAvg); //假设gps采样间隔为5s，人步行的速度大约为1m/s，那么定义相邻两点间平均间隔<8m的为步行，并定义最大步行速度为1.5 //骑车与开车同理，阈值可根据实际情况作更改 if (disAvg < 8) { state = 1.5f;//走路 } else if (disAvg >= 8 && disAvg < 30) { state = 5;//骑车 } else { state = 15;//开车 } } //获取最长的合理轨迹 public static String getSafeIndex(ArrayList<double[]> gpsList) { int start = 0; int end = 0; List<String> indexList = new ArrayList<>(); double[] dangerBefore = null; // Log.i("safe", "getGpsIndex:" + gpsList.size()); for (int i = 1; i < gpsList.size(); i++) { double[] dangerVo = gpsList.get(i); if (dangerBefore == null) { dangerBefore = gpsList.get(i - 1); } //米 double distance = LocationConvert.getDistance(dangerVo[0], dangerVo[1], dangerBefore[0], dangerBefore[1]); //GPS采集频率，假定5秒 long time = 5; double speed = distance / time; if (speed > state) { if (end > start) { indexList.add(end + "-" + start); // Log.i("safe", "合理轨迹段:" + indexList.size()); } start = i; } end = i; dangerBefore = dangerVo; } if (end > start) { //最后一段合理轨迹 indexList.add(end + "-" + start); // Log.i("safe", "合理轨迹段:" + indexList.size()); } int maxIndx = 0; int max = 0; for (int i = 0; i < indexList.size(); i++) { int tmpEnd = Integer.valueOf(indexList.get(i).split("-")[0]); int tmpStart = Integer.valueOf(indexList.get(i).split("-")[1]); if (tmpEnd - tmpStart > max) { max = tmpEnd - tmpStart; maxIndx = i; } } // Log.i("safe", "最长合理轨迹:" + indexList.get(maxIndx)); return indexList.get(maxIndx); } //从最长合理轨迹两侧遍历，寻找异常点 public static void removeErrorPoint(ArrayList<double[]> gpsList) { checkState(gpsList);//判断巡河方式 // Log.i("safe", "阈值:" +state); String safeIndexs = getSafeIndex(gpsList); int startIndex = Integer.valueOf(safeIndexs.split("-")[1]); int endIndex = Integer.valueOf(safeIndexs.split("-")[0]); if (startIndex == 0 && endIndex == gpsList.size() - 1) { return;//轨迹正常 } List<Integer> deleteList = new ArrayList<>(); double[] safeVo = gpsList.get(startIndex); for (int i = startIndex - 1; i > -1; i--) { double[] dangerVo = gpsList.get(i); double distance = LocationConvert.getDistance(dangerVo[0], dangerVo[1], safeVo[0], safeVo[1]); long time = 5; double speed = distance / time; if (speed > state) { deleteList.add(i); } else { safeVo = dangerVo; } } safeVo = gpsList.get(endIndex); for (int i = endIndex + 1; i < gpsList.size(); i++) { double[] dangerVo = gpsList.get(i); double distance = LocationConvert.getDistance(dangerVo[0], dangerVo[1], safeVo[0], safeVo[1]); long time = 5; double speed = distance / time; if (speed > state) { deleteList.add(i); } else { safeVo = dangerVo; } } if (!deleteList.isEmpty()) { // Log.i("safe", "异常点数量:" + deleteList.size()); // 删除异常点 for (int i = 0; i < deleteList.size(); i++) { // Log.i("safe", "异常点:" + deleteList.get(i)); //删除一次size会变，所以需要-i try{ gpsList.remove(deleteList.get(i) - i); } catch (Exception e){ // Log.i("safe", "异常" ); } } } } }