遥感分辨率翻译.docx

2.3 Spatial Resolution, Pixel Size, and Scale2.3空间分辨率，像素大小和规模For some remote sensing instruments, the distance between the target being imaged and theplatform, plays a large role in determining the detail of information obtained and the total areaimaged by the sensor. Sensors onboard platforms far away from their targets, typically view alarger area, but cannot provide great detail. Compare what an astronaut onboard the spaceshuttle sees of the Earth to what you can see from an airplane. The astronaut mightyou’re yourwhole province or country in one glance, but couldnt distinguish individual houses. Flying overa city or town, you would be able to see individual buildings and cars, but you would beviewing a much smaller area than the astronaut. There is a similar difference between satelliteimages and airphotos.对于一些遥感仪器，被成像的目标和平台之间的距离，在确定获得的信息和由传感器成像的区域的细节方面起到了很大的作用。当传感器平台离被测目标很远时，通常会看到较大的范围，但不能提供大量的细节。就像宇航员在航天飞机上看地球和你在飞机上看地球一样。宇航员可能一眼看到整个省或国家，但不能区分个人住房。飞越城市或城镇，你将能看到个别的建筑物和汽车，但比起宇航员，你看到的是一个更小的区域。卫星影像和航片也有类似的区别。The detail discernible in an image is dependent on thespatial resolution of the sensor and refers to the size ofthe smallest possible feature that can be detected.Spatial resolution of passive sensors (we will look at thespecial case of active microwave sensors later) dependsprimarily on their Instantaneous Field of View (IFOV).The IFOV is the angular cone of visibility of the sensor (A)and determines the area on the Earths surface which isseen from a given altitude at one particular moment intime (B). The size of the area viewed is determined bymultiplying the IFOV by the distance from the ground tothe sensor (C). This area on the ground is called theresolution cell and determines a sensors maximumspatial resolution. For a homogeneous feature to bedetected, its size generally has to be equal to or larger than the resolution cell. If the feature issmaller than this, it may not be detectable as the average brightness of all features in thatresolution cell will b