Threshold = 1.01 |
Threshold = 1.1 |
Threshold = 1.2 |
Threshold = 1.3 |
Threshold = 1.4 |
Threshold = 1.5 |
Threshold = 1.6 |
Threshold = 1.7 |
Threshold = 1.8 |
Summary of comparisons: Increasing the value of the threshold (from 1.01 to 1.8) effectively reduces the likelihood that a pixel will be classified as being influenced by topography. Clearly there has to be some checks with the original ERS intensity data (a good indication of the topographic variation within a scene) to ensure that the mountainous or hilly areas are removed from the analysis. The recommended threshold of 1.4 yields a reasonable estimate of those regions with significant topography in the scene shown below.
NOTE: edges are drawn around each image for clarityWindow size = 20, filter = median
Threshold = 1.01 |
Threshold = 1.1 |
Threshold = 1.2 |
Threshold = 1.3 |
Threshold = 1.4 |
Threshold = 1.5 |
Threshold = 1.6 |
Threshold = 1.7 |
Threshold = 1.8 |
Window size = 20, filter = mean
Threshold = 1.01 |
Threshold = 1.1 |
Threshold = 1.2 |
|
Threshold = 1.3
Threshold = 1.4
Threshold = 1.5 | |||
Threshold = 1.6 |
Threshold = 1.7 |
Threshold = 1.8 |
