Unable to export transect pixel... but it works with export mask pixel?

i am trying to do this several time but it is not happening. when I "export trasect pixels… no sigma0 values are shown. but when I do “export mask pixel” the value appears. why… one more question… can we calculate the total distance of the transect line and plot??

Export transect pixels only works with digitized line.
Export mask works with polygons.

Can you clarify what exactly you did?

I have drawn a line using “line draw tool”. and then right click to export the value…

What exactly does not work?

Option 1

I digitize a line and right-click > Export Transect Pixels
grafik

I select Write to File
grafik

This is the file
grafik

Option 2

Digitize a line and select the profile plot tool

Switch to the table view grafik

Right-click > Copy Data to Clipboard
grafik

This is the data

i havenot done the second step… drawing profile plot…


I want am curious about how they have plotted backscattering value against the distance (in m). 0 to 800 (or any) can be calculated. but how to plot Distance by backscattering value of pixels>> can you please help?

I’m afraid SNAP currently only supports the plot against pixels and not metric lengths.

But you can measure the lengh of your digitized line and create a plot in MS Excel based on the exported Sigma0 values

https://scholar.google.com/citations?user=IjMdOxcAAAAJ&hl=en#d=gs_md_cita-d&u=%2Fcitations%3Fview_op%3Dview_citation%26hl%3Den%26user%3DIjMdOxcAAAAJ%26citation_for_view%3DIjMdOxcAAAAJ%3AUeHWp8X0CEIC%26tzom%3D-330

i am referring this issue from this paper… indeed I tried a lot to plot distance by pixel value. impossible for me. indeed it is not rational to plot a 10 *10 pixel against a point … i my is afraid off.

How about my work around above?

  1. Digitize a line

  2. Measure the line
    grafik

  3. Export transect pixels

  4. Import the pixel values in MS Excel

  5. I have 353 values, so 0 is 0 meters and 353 is 4000 meters. The distances between can be calculated using a linear equation.

  6. Accordingly, each pixel along this diagonal corresponds to 11.365 m
    grafik

  7. I calculate the distance along the line and create a plot:

Such a great work. I will try and reply to you soon.