Oliver:
If you are using ALOS JAXA PALSAR 1.5
data, this may be useful
http://www.eorc.jaxa.jp/ALOS/en/doc/fdata/PALSAR_x_Format_EL.pdf
Calibration factor (CF) F
Level 1.1 : s0 = 10 * log10<I2+Q2>
+ CF - 32.0
Level 1.5 : s0 = 10*log10<DN2> + CF
This means that the
sigma-naught of the pixel can be obtained by the ensemble G
averaging (<>) of
the pixel values, in reality, the spatial averaging of the pixel
values around the
target.Here, I, Q, and DN in <> of the above formulas are
the pixel values in levels 1.1, and 1.5,
respectively.
Philip
From: OLIVIER TSUI
[mailto:otsui1@xxxxxxxxx]
Sent: Wednesday, October 07, 2009
7:22 PM
To: PCI Geomatics Discuss List
Subject: Generate calibrated radar
backscatter image from PALSAR
Hello List,
I have an ALOS PALSAR Level 1.5 image and I would like to generate a calibrated
radar backscatter image. I know for RADARSAT-1/2 and Envisat ASAR, the
SARSIGM algorithm is used however when I ingest the raw PALSAR data from CEOS,
I do not have the SAROffset, SARIncAngle, SARGain segments in the PIX file
nceessary to run SARSIGM.
Has anyone come across this before? How would I go about creating a calibrated
backscatter image? Do I need to obtain data with Level 1.0 or 1.1
processing?
Thank you in advance for your help.
Regards,
Olivier