并建立了一种纹理相似性度量指标CO-RMSE(Co-Occurrence Root Mean Square Error)。结果表明:(1)NDVI方法受季节影响最严重
不适于春、冬季
其次为PBIM方法;(2)LSMM方法受分辨率限制最大
低分辨率时丢失大量纹理信息
NDVI方法在较高分辨率时优于PBIM方法
较低分辨率时则相反;(3)3种方法的适用区域分别为植被与裸土像元并存区域
山区和反照率变化较大区域
以及类别间温差较大区域;(4)NDVI方法操作最简单
LSMM方法最复杂。分析认为
尺度因子是决定方法性能的关键
应根据季节、分辨率、地表覆盖、应用目的和操作性等综合选择。
Abstract
Remotely sensed Land Surface Temperatures (LSTs) usually have low spatial resolutions. Downscaling is an effective technique to enhance the spatial resolutions. Current methods for downscaling remotely sensed LSTs were summarized. Using satellite data
we made an inter-comparison among three typical methods
including the Normalized Difference Vegetation Index (NDVI) method
the Pixel Block Intensity Modulation (PBIM) method
and the Linear Spectral Mixture Model (LSMM) method. We further designed an index
Co-Occurrence Root Mean Square Error (CO-RMSE)
for measuring the textural similarity in inter-comparisons. Results indicate that (1) the performance of the NDVI method is most affected by the season
followed by the PBIM method; (2) the performance of the LSMM method is most influenced by the spatial resolution; the NDVI method has an advantage over the PBIM method at high resolutions
while at low resolutions
the performance of the PBIM method is better than that of the NDVI method; (3) these three methods are suitable for areas with combination of vegetation and bare ground
areas with varied topography and albedo
and areas with distinct LST differences in different classes
respectively; (4) the NDVI method is the easiest to implement
while the LSMM method is the most difficult. Further analysis showed that scale factor is the key issue to the LST downscaling and it needs to be carefully selected regarding the season
spatial resolution
land cover
application and the operability.
关键词
地表温度降尺度尺度因子CO-RMSE
Keywords
land surface temperaturedownscalingscale factorCO-RMSE