ratio image = (SAR image at very windy conditions)/(SAR image at very calm conditions)
In calm conditions water surfaces have very low backscatter values, and in windy conditions the backscatter can be quite high -> ratio images detect water-bodies quite nicely.
very nice! Thanks for sharing it! Is there a specific rate expected that we should obtain from this image ratio (sth between a and b) specifically for water? In other words, how we can recognize e.g., image ratio of 3 is for the water bodies?
Hello.
i try to execute a change detection with l1 data.
my proc.graph is: productsetreader->create stack -> cross correlation-> changedetection ->write
But everytime it appears the failure: “ArrayIndexOutOfBoundsExeption”
I figure out that if i split the chain in 2 parts, like this: productsetreader->create stack -> cross correlation-> write1
and then i start a new graph wich uses the write1-output for the the secondgraph: read(from write1)->changedetection ->write it works.
why dont it work if i use the composite graph?
Btw: productsetreader uses a orbit applied,radiometric, geometric calibrated, despeckled L1 data.
thx
Hello A5iveMM,
maybe the problem is that your co-registration process lacks the warp step. Try to append warp after cross correlation, it should work.
Gabriele
lveci is right. The images are not aligned correctly. If a larger cross correlation window doesn’t work either try terrain correcting both first and then create a stack with coregister > create stack
Hi
I have some question about change detection
first of all what is the best data format for change detection? slc or grd / IW or EW or WV or SM/ and what polarization?
second is there any tutorial or step by step processing guide for doing change detection?