GAMMA Questions

Hello,
When providing the interferogram and the two coregistered intensity images,
standard formula
for interferometric coherence is used as stated in first equation in the
documentation.
Use this command to read the documentation of cc_wave in your web browser:

gamma_doc cc_wave

The file cc_wave.html is in the $ISP_HOME/html directory. You can also just
double click on this file
to read the documentation.

Hello,
When providing the interferogram and the two coregistered intensity images,
standard formula
for interferometric coherence is used as stated in first equation in the
documentation.
Use this command to read the documentation of cc_wave in your web browser:

gamma_doc cc_wave

The file cc_wave.html is in the $ISP_HOME/html directory. You can also just
double click on this file
to read the documentation.

Hello Charles,

Thanks for you reply.

I have already referenced the first equation in the documentation, and tried to use it to estimate the correlation coefficient with a moving window.

However, I still not obtain a correct result, because I don't know what these paremeters (xi and yi) mean.

Regards.

The documentation says "xi and yi are samples of the coregistered SLC images."

But the input parameters only contain the interferogram and two coregistered intensity images,

how to generate the input values acquired in the equation form these input files?

Hi Xp Liu,

x_i are the samples of the first SLC, and y_i are the samples of the second SLC.

There are N SLC samples in the rectangular window defined by width bx and height
by and
the vertical bars denote magnitude.  The correlation is the magniude of the sum
of single sample interferogram values (x_i * conjg(y_i))
divided by the geometric mean of the average intensity of SLCs.

In the gamma software, the the interferogram is already normalized so that the
magnitude of the interferogram values are
between 0.0 and 1.0. The magnitude of the interferogram values is a correlation
estimate performed with the number of range and azimuth looks that were
specified when it was calculated.

cc_wave lets you estimate the correlation of the scene with a different number
of range and azimutb looks than was used to form the interferogram
To do that, you need to denormalize the interferogram values to permit averaging
over a different size region, and that is why you need the intensity values.

Best regards,
Charles

Dear Charles,

I got it.

Many thanks!