电子科技大学：《遥感图像处理 Remote Sensing Image Processing》课程教学资源（课件讲稿）第五章 遥感图像的校正与定标

第五章 遥感图像的校正与定标 1

1 第五章 遥感图像的校正与定标 UESTC-RSIP

图像几何形变 INCLINATION OF LANDSAT ORBIT TO C-RSIP Orbit 16,day 2 Orbit 2.day I MAINTAIN SYNCHRONOUS ORBIT Orbit 15,dey 2 LANDSAT AT12为NO0 Orbit 1.day I LOCAL TIME EQUATORIAL AN 1851 LANDSAT AT 042 AM LOCAL TIME 2875 km at the Equator 159hm 2

2 图像几何形变 UESTC-RSIP

Equatorial 98.29 plane and direction of Earth rotation: west to cast Landsats 4.5.7 ocal time Pixels in a Landsat Thematic Pixels in a Landsat Thematic Mapper dataset prior to correcting Mapper dataset corrected for Earth rotation effects for Earth rotation effects Landsat Earth rotates satellite TC-RSIP west to east line of flight ↓ 23456 Entire scan consisting of 16 lines offset to correct for Earth rotation effects Usually padded with null values (e.g.BVij=0) 3 ■■■■■■■■■■■■■ contimed continued

3 UESTC-RSIP

Corrected image scene orientation 'map' Uncorrected data 'path USGS 1 millionth Landsat scene downloaded G时C我SA Ladh减5 = 4

4 Corrected image scene orientation ‘map’ Uncorrected data ‘path’ UESTC-RSIP

Scanning System-induced Variation in Ground Resolution Cell Size The ground resolution cell size along a single across-track scan is a function of a) the distance from the aircraft to the observation where H is the altitude of the aircraft above ground level (AGL)at nadir and H sec f off-nadir; Total field b) the instantaneous-field-of-view of the of view of sensor,b,measured in radians;and one scan line c) the scan angle off-nadir,f.Pixels off- =Hsec nadir have semi-major and semi-minor B axes (diameters)that define the Instantaneous 4 field of view resolution cell size.The total field of Scan angle view of one scan line is q. off-nadir (H sec B (H sec)B D=BxH at nadir Lime of flight 5

5 Scanning System-induced Variation in Ground Resolution Cell Size The ground resolution cell size along a single across-track scan is a function of a) the distance from the aircraft to the observation where H is the altitude of the aircraft above ground level (AGL) at nadir and H sec f off-nadir; b) the instantaneous-field-of-view of the sensor, b, measured in radians; and c) the scan angle off-nadir, f. Pixels off￾nadir have semi-major and semi-minor axes (diameters) that define the resolution cell size. The total field of UESTC-RSIP view of one scan line is q

地形起伏 bob n ao a bo 40 H 十h。 岛 E A Ao %7777 B B 6

6 地形起伏 UESTC-RSIP

地球表面曲率的影响 像点位置的移动 像元对应于地面宽度的不等 an a F S 产扫描方向 4九3/ L,Li Ao h P3 9卫斜

7 地球表面曲率的影响 像点位置的移动 像元对应于地面宽度的不等 UESTC-RSIP

大气折射的影响 △r RSIP UES N P 8

8 大气折射的影响 UESTC-RSIP

Geometric Modification of Remotely Sensed Data Caused by Changes in Platform Altitude and Attitude a.Change in Altitude Decrease in altitude x-axis creates larger-scale image Nominal Increase in altitude creates smaller-scale image SIXE- 传感器位置和姿态 Direction of flight compression expansion expansion compression Roll rotation wing abo川 up and x-axis down angle motion nose compression ←pdown downA fore expansion fore Pitch rotation fuselage about up and V-axis down angle motion expansion aft compression tail aft down frame of imagery 2-axis rotation about Yaw aircraft flies straight z-axis but fuselage is angle x crabbed into wind 9

9 传感器位置和姿态 UESTC-RSIP

10 UESTC-RSIP