探測地球雲層分布的CloudSat和CALIPSO衛星
http://www.nasa.gov/mission_pages/calipso/main/index.html
http://www.nasa.gov/topics/earth/features/calipso-1billion.html
Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO)
The occasion was on CALIPSO's 9,491st orbit of Earth. Since its launch, on April 23, 2006, the satellite has traveled 260,198,685.3 miles. It has generated data that would fill almost 3,500 DVDs or more than 24,000 CDs, delighting scientists and researchers from 35 countries who are using the information to prove any number of theories about the atmosphere, about weather, about the past and how it will relate to the future.
資料格式
1 double lonFrom = 0;
2 double latFrom = 0;
3 double lonTo = 0;
4 double latTo = 0;
5 OSGeo.GDAL.Gdal.AllRegister();
6 Gdal.SetConfigOption("GDAL_FILENAME_IS_UTF8", "Yes");
7 string path = string.Format(@"C:\Users\Desktop\lidar_track_image\CAL_LID_L1-ValStage1-V3-02.2013-01-01T18-30-59ZN_Subset.hdf", WorldSettings.StartupDirectory);
8 //path = string.Format(@"{0}\data\CAL_LID_L1-ValStage1-V3-02.2013-01-01T18-30-59ZN_Subset.hdf", WorldSettings.StartupDirectory);
9 byte[] pathUtf16 = Encoding.Unicode.GetBytes(path);
10
11 byte[] byteUtf8 = Encoding.Convert(Encoding.Unicode, Encoding.UTF8, pathUtf16);
12
13 string pathUtf8 = Encoding.UTF8.GetString(byteUtf8);
14
15 Encoding encoud = Encoding.GetEncoding(936);
16 byte[] byteGb2312 = Encoding.Convert(Encoding.Unicode, encoud, pathUtf16);
17 string pathGb2312 = encoud.GetString(byteGb2312);
18
19 if (!File.Exists(path))
20 {
21 MessageBox.Show("Calpso資料不存在", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
22 return;
23 }
24 //讀取檔案，擷取子資料集資訊
25 Dataset ds = Gdal.Open(path, Access.GA_ReadOnly);
26 string[] stMetadata = ds.GetMetadata("");
27 string[] strMetadata = ds.GetMetadata("SUBDATASETS");
28 string info = string.Empty;
29 for (int i = 0; i < strMetadata.Length; i++)
30 {
31 info += strMetadata[i] + "\n";
32 }
33 info += "讀取波段資料:----------------\n";
34 //緯度資料
35 string tmpstr = strMetadata[0];
36 tmpstr = tmpstr.Substring(tmpstr.IndexOf("=") + 1);
37 Dataset dsLat = Gdal.Open(tmpstr, Access.GA_ReadOnly);
38 string strMetadata2 = dsLat.GetDescription();
39
40 info += string.Format("像素數目：{0} X {1}", dsLat.RasterXSize, dsLat.RasterYSize);
41 int count = dsLat.RasterCount;
42 Band bandLat = dsLat.GetRasterBand(1);
43 int Cols = dsLat.RasterXSize;
44 int Rows = dsLat.RasterYSize;
45 int width = dsLat.RasterXSize;
46 int height = dsLat.RasterYSize;
47 double min, max, no;
48 int hasvalue;
49 info += string.Format("類型Lat：{0}\n", bandLat.DataType);
50 if (bandLat.DataType == DataType.GDT_Float32)
51 {
52 bandLat.GetMaximum(out max, out hasvalue);
53 bandLat.GetMinimum(out min, out hasvalue);
54 bandLat.GetNoDataValue(out no, out hasvalue);
55 float[] data = new float[Cols * Rows];
56 bandLat.ReadRaster(0, 0, width, height, data, Cols, Rows, 0, 0);
57
58 string ddd = string.Empty;
59 double min1, max1, mean, hasvalue1;
60 OSGeo.GDAL.Gdal.GDALProgressFuncDelegate dele = new Gdal.GDALProgressFuncDelegate(GDALProgressFunc);
61 bandLat.ComputeStatistics(false, out min1, out max1, out hasvalue1, out mean, dele, ddd);
62 lonFrom = data[0];
63 lonTo = data[data.Length - 1];
64 }
65 //經度資料
66 string tmpstrLon = strMetadata[2];
67 tmpstrLon = tmpstrLon.Substring(tmpstrLon.IndexOf("=") + 1);
68 Dataset dsLon = Gdal.Open(tmpstrLon, Access.GA_ReadOnly);
69 info += string.Format("像素數目：{0} X {1}", dsLon.RasterXSize, dsLon.RasterYSize);
70 Band bandLon = dsLon.GetRasterBand(1);
71 int Cols2 = dsLon.RasterXSize;
72 int Rows2 = dsLon.RasterYSize;
73 int width2 = dsLon.RasterXSize;
74 int height2 = dsLon.RasterYSize;
75 double min2, max2, no2;
76 int hasvalue2;
77 info += string.Format("類型Lon：{0}\n", bandLon.DataType);
78 if (bandLon.DataType == DataType.GDT_Float32)
79 {
80 bandLon.GetMaximum(out max2, out hasvalue2);
81 bandLon.GetMinimum(out min2, out hasvalue2);
82 bandLon.GetNoDataValue(out no2, out hasvalue2);
83 float[] data2 = new float[Cols2 * Rows2];
84 bandLon.ReadRaster(0, 0, width2, height2, data2, Cols2, Rows2, 0, 0);
85
86 string ddd = string.Empty;
87 double min1, max1, mean, hasvalue1;
88 OSGeo.GDAL.Gdal.GDALProgressFuncDelegate dele = new Gdal.GDALProgressFuncDelegate(GDALProgressFunc);
89 bandLon.ComputeStatistics(false, out min1, out max1, out hasvalue1, out mean, dele, ddd);
90 latFrom = data2[0];
91 latTo = data2[data2.Length - 1];
92 }
93 //讀取雷達衰減系數
94 string tmpStrBackScatter = strMetadata[70];
95 tmpStrBackScatter = tmpStrBackScatter.Substring(tmpStrBackScatter.IndexOf("=") + 1);
96 Dataset dsBackScatter = Gdal.Open(tmpStrBackScatter, Access.GA_ReadOnly);
97 info += string.Format("像素數目：{0} X {1}", dsBackScatter.RasterXSize, dsBackScatter.RasterYSize);
98 Band bandBackScatter = dsBackScatter.GetRasterBand(1);
99 int ColsBackScatter = dsBackScatter.RasterXSize;
100 int RowsBackScatter = 3000;// ds270.RasterYSize;讀取3000個像素
101 int widthBackScatter = dsBackScatter.RasterXSize;
102 int heightBackScatter = 3000;// ds270.RasterYSize;
103 double min270, max270, no270;
104 int hasvalue270;
105 info += string.Format("類型衰減系數：{0}\n", bandBackScatter.DataType);
106 if (bandBackScatter.DataType == DataType.GDT_Float32)
107 {
108 bandBackScatter.GetMaximum(out max270, out hasvalue270);
109 bandBackScatter.GetMinimum(out min270, out hasvalue270);
110 bandBackScatter.GetNoDataValue(out no270, out hasvalue270);
111 string ddd = string.Empty;
112 double mean, has;
113
114 OSGeo.GDAL.Gdal.GDALProgressFuncDelegate dele = new Gdal.GDALProgressFuncDelegate(GDALProgressFunc);
115 bandBackScatter.ComputeStatistics(false, out min270, out max270, out has, out mean, dele, ddd);
116 float[] data270 = new float[ColsBackScatter * RowsBackScatter];
117 bandBackScatter.ReadRaster(0, 0, widthBackScatter, heightBackScatter, data270, ColsBackScatter, RowsBackScatter, 0, 0);
118
119 int x1width = heightBackScatter;
120 int y1height = widthBackScatter;//583
121 Bitmap bitmap = new Bitmap(x1width, y1height, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
122 int iPixelSize = 4;
123
124 CreateColorRamp createColorRamp = CreateColorRamps();
125 BitmapData bitmapdata = bitmap.LockBits(new Rectangle(0, 0, x1width, y1height), ImageLockMode.ReadWrite, bitmap.PixelFormat);
126 try
127 {
128 unsafe
129 {
130 for (int y = 0; y < y1height; y++)
131 {
132 byte* row = (byte*)bitmapdata.Scan0 + (y * bitmapdata.Stride);
133
134 for (int x = 0; x < x1width; x++)
135 {
136 //int posSrc = x + y * x1width;
137 int posSrc = y + x * y1height;//圖像順時針旋轉90度
138 double item = data270[posSrc];
139 if (item == no270)
140 {
141 Color? getColor = getColor = createColorRamp.GetColor(0); ;
142 row[x * iPixelSize] = (byte)getColor.Value.B;
143 row[x * iPixelSize + 1] = (byte)getColor.Value.G;
144 row[x * iPixelSize + 2] = (byte)getColor.Value.R;
145 row[x * iPixelSize + 3] = getColor.Value.A;
146 }
147 else
148 {
149 Color? getColor = null;
150 if (item < 0.0001 || item > 0.1)
151 {
152 getColor = createColorRamp.GetColor(0);
153 }
154 else
155 {
156 getColor = createColorRamp.GetColor(item);
157 }
158 if (getColor != null)
159 {
160 row[x * iPixelSize] = getColor.Value.B;
161 row[x * iPixelSize + 1] = getColor.Value.G;
162 row[x * iPixelSize + 2] = getColor.Value.R;
163 row[x * iPixelSize + 3] = getColor.Value.A;
164 }
165 }
166 }
167 }
168 }
169 }
170 catch
171 {
172 }
173 finally
174 {
175 bitmap.UnlockBits(bitmapdata);
176 }
177 bitmap.Save("D:\\b.png");
178 Vector3d v1 = new Vector3d(lonFrom, latFrom, 0);
179 Vector3d v2 = new Vector3d(lonTo, latTo, 0);
180 Vector3d dir = v2 - v1;
181
182 Vector3d v3 = v1 + (double)heightBackScatter / dsBackScatter.RasterYSize * dir.Normalize();
183 CalpsoRenderObject obj = new CalpsoRenderObject("", v1, v3);
184 } View Code
1 public CreateColorRamp CreateColorRamps()
2 {
3 CreateColorRamp createColorRamp = new CreateColorRamp();
4 List<ColorRamp> mColorRamp = new List<ColorRamp>();
5 double[] valueGray = new double[35] {0.0, 0.0001,0.0002,0.0003,0.0004,0.0005,
6 0.0006,0.0007,0.0008,0.0009,0.001,
7 0.0015,0.002, 0.0025,0.003, 0.0035,
8 0.004, 0.0045,0.005, 0.0055, 0.006,
9 0.0065,0.007, 0.0075,0.008, 0.01,
10 0.02, 0.03, 0.04, 0.05, 0.06,
11 0.07, 0.08, 0.09, 0.1};
12 int[] Rv = new int[35] {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
13 255,255,255,255,255,255,255,255,255,255,
14 70,100,130,155,180,220,225,235,240,242,
15 245,249,253,255};
16 int[] Gv = new int[35] {43,43,43,128,170,213,255,255,255,128,
17 170,255,255,213,170,128,85,0,43,85,128,
18 70,100,130,155,180,220,225,235,240,242,
19 245,249,253,255};
20 int[] Bv = new int[35] {128,170,170,255,255,255,255,213,170,128,
21 85,0,0,0,0,0,0,0,85,128,170,
22 70,100,130,155,180, 220,225,235,240,242,
23 245,249,253,255};
24
25 for (int i = 0; i < 35; i++)
26 {
27 ColorRamp clr = new ColorRamp();
28 clr.start = valueGray[i];
29 if (i < 34)
30 {
31 clr.end = valueGray[i + 1];
32 }
33 clr.ColorS = Color.FromArgb(255, Rv[i], Gv[i], Bv[i]);
34 mColorRamp.Add(clr);
35 }
36 mColorRamp[mColorRamp.Count - 1].end = 100;
37 createColorRamp.ColorRampCollection = mColorRamp;
38 return createColorRamp;
39 }
40 int GDALProgressFunc(double Complete, IntPtr Message, IntPtr Data)
41 {
42 return 1;
43 } CreateColorRamp
1 public class ColorRamp
2 {
3 public double start;
4 public double Interval;
5 public double end;
6
7 public Color ColorS;
8 }
9 public class CreateColorRamp
10 {
11 public List<ColorRamp> ColorRampCollection { get; set; }
12 public Color? GetColor(double val)
13 {
14 if (ColorRampCollection == null)
15 {
16 throw new ArgumentNullException("顔色分級設定為空");
17 }
18 for (int i = 0; i < ColorRampCollection.Count; i++)
19 {
20 ColorRamp colorRam = ColorRampCollection[i];
21 if (val >= colorRam.start && val < colorRam.end)
22 {
23 return colorRam.ColorS;
24 }
25 }
26 return null;
27
28 }
29 }
30 } GDAL C#封裝還是沒有解決中文字元的問題。C# 采用Unicode，GDAL的Dll采用多位元組字元。是以隻能在C++的代碼中做些工作，将Unicode轉換為多位元組字元或者是Utf8。準備測試一下。
NASA上的圖檔：