课后作业.docx

1、课后作业遥感技术基础实习成果学年学期： 2011/2012学年 第二学期系 别： 地理信息工程系 班 级： 地102班 * * * 学 号： * * * * 提交日期： 2012年6月1日 实验成绩： Worksheet: Lab 01: Introduction To ENVI （作业，要求每个题在必要的地方要截图，对结果仔细分析后回答问题）1.What are the roles of the three different windows for one image? （影像显示时，三个不同窗口的作用是什么？）答：there are three windows, one is for i

2、mage, one is for scroll, one is for zoom.1.Main Image Window（主影像窗口） 主图像窗口是由一幅以全分辨率显示的图像的一部分组成。该窗口在你第一次载入一幅图时自动地被启动。2.Scroll Window （滚动窗口） 滚动窗口是一个以二次抽样的分辨率显示大图像的小图像显示窗口。只有要显示的图像比主图像窗口以全分辨率能显示的图像大时，才会出现滚动窗口。3.zoom Window（缩放窗口） 缩放窗口是一个晓得图像显示窗口，它以用户自定义的缩放系数使用象元复制来显示主图像窗口的一部分。2.What is the projection of

3、this image? what is the pixel spatial resolution? （给定影像的投影方式是什么？空间分辨率是多少？）横轴墨卡托投影 分辨率为 25米3.Describe the TM image that you originally opened using the standard false color composition（标准假彩色合成） (in an RGB image, Band 4 （近红外波段）for channel R（红通道）, Band 3 （红波段）for channel G（绿通道）, Band 2 （绿波段）for channel

4、 B) （蓝通道）. （影像的彩色合成）a.What color is the vegetation surrounding town? Why? （城区外围植被是什么颜色，为什么？）红色植被在近红外和红外波段的反射特性，-R，所以是红色。b.What color is the water body? Why? （水体是什么颜色，为什么？）黑色水体在近红外波段反射率几乎为零4.Describe the TM image that you originally opened using another false color composition（另一种假彩色合成） (in an RGB im

5、age, Band 5 for channel R, Band 4 for channel G, Band 3 for channel B). （影像的彩色合成）a.What color is the vegetation surrounding town? Why? （城区外围植被是什么颜色，为什么？）绿色，在近红外波段植被反射设置为绿色b.What color is water body? Why? （水体是什么颜色，为什么？）黑色理由如3-2，水体在近红外波段反射率几乎为零5.What band and color combinations are required to make th

6、e image look like what your eye would see (“true color”)? (如何合成一景真彩色影像？) a.What color is the vegetation surrounding town? Why? （城区外围植被是什么颜色，为什么？）绿色植被绿色设置正确b.What color is water body? Why? （水体是什么颜色，为什么？）蓝色水体蓝色设置正确。c.Please make a comparison of the vegetation color, water body color based on the resul

7、ts from questions 3,4 and 5. （对3，4，5中植被、水体的颜色作一个对比. ）3，4水体都是黑色，而5是蓝色，水体在除蓝色以外波段吸收巨大，几乎不反射。6.Based on the Layer Information window provide the following information about the TM image file: （TM影像的相关信息）a.How many bands does the image have? （影像有几个波段？）7个b.What is the mean pixel value for Band 4? （第4个波段像

8、素DN值的平均值是多少？） 106.119806 c.What is the minimum pixel value for Band 2? （第2个波段像素DN值的最小值是多少？） 0 d.What is the histogram for all bands like in this image? （显示该影像所有波段的直方图。）7.Link band 2 and band 6 based on geographical locations: （基于地理位置对波段2和波段6进行关联）a.What are the DN values of water body surrounding for

9、bidden city in band 2 and band 6? (波段2和波段6中紫禁城外水体的DN值各是什么？)波段2是32，波段6为138b.What are the DN values of vegetation in Tiantan Park in band 2 and band 6? (波段2和波段6中天坛公园植被的DN值各是什么？)波段2为36 波段6为142Worksheet: Lab 2: Converting Radiance to Reflectance1.Draw a diagram showing the path of light from the sun to

10、the earth, and the reflected path from the earth to the satellite. Label all of the places/processes in this diagram that affect how much light (radiance) is received at the satellite. （画一个草图来表示太阳光到地球并从地球反射到卫星的过程，并标明影响光线传输到卫星的每个过程的名称，可以用画图工具完成后插入到word中）2.Fill in the following table: Image FileData T

11、ype（数据类型）Band 3 Data Range（第三个波段的数值范围）Band 4 Data Range（第四个波段的数值范围）Original DN Value原始DN值整数02550255Radiance (calculated)辐射率小数0.000000264.0000000.000000220.999985Reflectance (calculated)反射率小数0.0000000.3216120.0000000.8091363.What is the % reflectance in the Near Infrared band of the pixels that occup

12、ies Row 727 and Column 5090, Row 2937 and Column 521? （using pixel locator to locate the position） （第727行、5090列和第2937行、521列像素在近红外波段的反射率各是多少？各像素分别为何地物？是否于其光谱曲线符合？）（提示利用image窗口中，tools下的pixel locator来确定像素的位置，注意列在前，行在后） 第727行、5090列湖泊，符合水吸收了所有光谱 第2937行、521列云层，符合，云层反射了所有光谱Worksheet: Lab 03: Exploring Digi

13、tal Data1.Which bands do you assign to blue, green, and red primary colors, respectively, to display a true color image (what your eye would see)? （合成真彩色影像）When you assign band 6 to red, band 3 to green and band 2 to blue, what doesvegetation look like in the resulting image? What does this tell you

14、 about vegetation reflectance? （6,3,2分别赋给R,G,B，合成影像，其植被的颜色是什么？）植被颜色为紫色2.Draw a line from your ROI ascii file here for pixels of water, vegetation, building, road and bare soil respectively. 利用excel绘制水体、植被、建筑、道路和裸地的光谱曲线，插入到本题后。水体：植被：建筑：道路：裸地：Does this reflectance curve resemble the shape of the typic

15、al vegetation reflectance curve? （植被的光谱是否符合理论上所学的植被的光谱？）符合，在红外近红外波段反射效果明显3.Draw spectral profiles (just reproduce the general shape) below for vegetation, Tiananmen Square and water pixels from the TM image. For each, state whether you think the pixel is “pure” or do you think it contains a mixture

16、of materials. Explain your answers. （利用ENVI工具制作植被、天安门广场和水体的光谱曲线。对于每一个曲线，请考虑其是纯像元还是混合像元，为什么？）植被是混合像元：在一个像元内存在不同类型的地物。天安门：是混合像元：在一个像元内存在不单一是广场的地物。水体：纯像元：因为，都是水4.Try to cursor DN values for water body? Why are the values for water so consistently low? (在不同波段浏览水体处的DN值，与其他地物相比，为什么水体的DN值在各个波段都都很低)水体对于光线的吸

17、收能力大体上非常强，所以较低。5.Try to cursor DN values for forest? Why is it that the forest values are relatively low in bands 1, 2 and 3, but abruptly increase in bands 4 and 5?（浏览林地的DN值，请回答为什么林地在1,2,3波段的DN值很低，在波段4,5的DN值却很高？）植被在红外近红外波段反射能力较强(4.5)。Lab 4: Spatial, Spectral and Radiometric Resolution (空间、光谱和辐射分辨率)

18、In this exercise you will explore imagery with different spatial, spectral and radiometric resolutions. Choosing satellite data as a tool for various tasks (e.g., mapping vegetation, delineating roads) requires that you balance the advantages of higher resolution with cost. Keep this in mind as you

19、look at the imagery in this exercise. SPATIAL RESOLUTION （空间分辨率）1) First you will examine satellite images of the Beihai, Beijing area collected by three different sensors that have different spatial resolutions. These are: Geoeye 1 image (cell size = 0.5m)(Geoeye), Spot Image（cell size =2.5m) (SP)

20、and the Landsat Thematic Mapper (TM) (cell size = 30 m) (tm). （三种传感器数据，分别是Geoeye（0.5米）， Spot （2.5米），TM（30米）2) These images are stored in the folder called Data. Open them as follows:a. Open the Geoeye-1 image (geoeye) as a true color image and assign R to red, G to green, and B to blue.(打开Geoeye数据，制

21、作真彩色影像图)b.Open the Spot image (SP) as a pseudocolor image and assign band 1 to red, band 2 to green, and band 3 to blue. (打开Spot数据，制作假彩色影像图)c.Open the TM image (TM) as a standard false color image and assign band 4 to red, band 3 to green and band 2 to blue. (打开TM数据，制作标准假彩色影像图)3) For each of the 3 i

22、mages, indicate with a checkmark in the table below which features you can resolve (see). (标出是否能够看清楚指定的特征，可以用清晰、模糊、分辨不出来形容)FeatureGeoeye (0.5m)Spot Image (2.5m)TM Image (30 m)Large area of water body （大面积的水域）清晰清晰模糊Building （建筑）清晰清晰模糊Road（道路）清晰清晰模糊Individual trees（树）清晰分辨不出分辨不出Cars in parking lot or r

23、unning on road （车辆）模糊分辨不出分辨不出Can you see features that are narrower or smaller than the size of a pixel (e.g., is a road that is less than 30 m wide visible in the TM image?)? If so, why do you think this would be? （你能分辨出比实际像素小的特征地物么？（比如，在TM影像上，比30米窄的道路可以分辨出么？）为什么？）不能，因为像素是人可以分辨出的最小特征尺寸在TM影像上，比30米窄的

24、道路比像素小，所以看不清Based just on differences in spatial resolution, what types of applications might each satellite (Geoeye, Spot, TM) be good for. （根据其分辨率的不同，每种卫星的数据可能用于那些方面？）GeoEye：影像收集、地理空间和影像获取，以及信息服务。公司为全球市场提供图像及信息产品以绘图、测量和监视地球，其应用领域包括：国防和情报部门、国家制图市场、在线地图用户、挖掘市场、油气市场、建筑/工程公司、森林和环境评估市场等。GeoEye作为卫星和航空影像

25、、定位信息产品和影像处理服务的提供商，其产品和服务旨在为用户提供及时、准确的重要定位信息。TM:能够反射浅水水下特征，可区分土壤和植被、编制森林类型图、区分人造地物类型。探测健康植被绿色反射率、可区分植被类型和评估作物长势，区分人造地物类型，对水体有一定透射能力。可测量植物绿色素吸收率，并依次进行植物分类，可区分人造地物类型。测定生物量和作物长势，区分植被类型，绘制水体边界、探测水中生物的含量和土壤湿度。：用于探测植物含水量及土壤湿度，区别云与雪。探测地球表面不同物质的自身热辐射的主要波段，可用于热分布制图，岩石识别和地质探矿等方面。短波红外：推测高温辐射源，如监测森林火灾、火山活动等，区分人

26、造地物类型。Spot：应用于地质勘测；农业生产；林业评估；土地利用检测牧场等。Can you see the shape of the classic vegetation reflectance curve in the graph you created for the Geoeye data? What are the important characteristics of this curve at this spectral resolution? （根据Geoeye做出的植被的光谱曲线，你能看出植被的光谱曲线形状么？在这种光谱分辨率的曲线中，有何特性？）能，绿色突出How abo

27、ut in the curve from the TM image? Can you see the shape of the typical vegetation spectrum? （TM数据的植被光谱怎么样？从中可以看出典型植被的光谱曲线么？）可以，红色波段明显How about the curve from the ASTER data? Can you see the shape of the typical vegetation spectrum? （ASTER数据的植被光谱怎么样？从中可以看出典型植被的光谱曲线么？）1.通过对影像进行快速统计，各影像的DN值范围是多少？为什么是这

28、样的数值范围？TMBasic Stats Min Max Mean Stdev Band 1 62 211 89.114275 11.611570 Band 2 27 145 47.915588 9.500303 Band 3 22 206 57.535595 15.327271 Band 4 9 161 62.872689 15.673028 Band 5 5 234 84.670673 25.601810 Band 6 0 143 42.802422 16.822339ASTERasic Stats Min Max Mean StdevBand 1 35.152000 164.944000

29、 57.969769 10.352747Band 2 17.700001 130.272003 39.928081 10.319889Band 3 18.101999 106.888000 46.628289 9.169347Band 4 16.378000 114.645996 52.243588 11.233229Band 5 2.391400 14.565800 7.928982 1.597631Band 6 0.974400 4.384800 2.296851 0.411869Band 7 0.750000 5.062500 2.186530 0.465974Band 8 0.6567

30、00 4.059600 1.947731 0.392481Band 9 0.417000 3.294300 1.332940 0.299446Band 10 0.445200 2.098800 0.895545 0.155120Band 11 8.038176 10.495049 9.529442 0.436754Band 12 8.536020 11.200560 10.253052 0.485500Band 13 8.975580 11.690660 10.724726 0.501867Band 14 9.273896 11.676343 10.817638 0.436340 Band 1

31、5 8.945200 11.071774 10.288395 0.374440GeoeyeBasic Stats Min Max Mean Stdev Band 1 0 255 66.877902 43.671345 Band 2 0 255 69.470139 42.512629 Band 3 0 255 63.283326 40.3201252.How many Landsat pixels are found in a square area that is 3 km on each side? （一个3公里*3公里的地面面积需要多少Landsat的像素才能扫描完全？（TM分辨率30m）（3公里*3公里）/（30米*30米）=10000个像素3.How many DNs would there be for the area above if the Landsat image has 6 bands?（如果TM有6个波段，上述面