I just wanted to share with all this processing flow in SNAP with ALOS PALSAR 2. All help or advice is welcome!
Download the product (HH and HV polarizations)
Geometric / Collocation
Convert both images (HH and HV) to DB
Create a new band dividing HH by HV
Apply a speckle filter
On the other hand, I use the HV decibels band (created on the step 3.) to make a forest/non forest mask, but the limit (according to the histogram) is around -47 or -48 decibels.
Thanks in advance for your suggestions!!
Thank you for sharing, this looks nice.
Just one comment: You probably missed to add the 32 as a constant in the equation. This would probably result in the expected valid range of values (-40 to +10)
Source: Calibration Result of ALOS-2/PALSAR-2 JAXA Standard Products
Thank you so mucha Andreas
The equation I’ve introduced in Band Math is this:
I didn’t know that was necessary a constant of 32…
So the expression would be?:
(10*Log10 (DN2) - 83 dB) +32
Hm, the documentation you showed is quite clear about it, you’re right. The unexpected range just reminded me of t this additional constant, but it applies to Level1.1 data only.
So it would make sense from a mathematical point of view, but not from the theory side…
As always, thank you Andreas
I have written to the ALOS PALSAR 2 support: firstname.lastname@example.org
I will keep you updated!