No License

  • Tutorial: tmnov is a tutorial image
    • as such, it is fully licensed and shall be processed
  • Chequered on our own image: suppose you are working on your own dearest image and you have managed to get ready for modeling
    • 4SM shall issue/display a license key and proceed to write out a chequered image
  • Chequered on tmnov: you can mimic the previous situation on a licensed image (here tmnov) by entering
    • -PROCESS/no/...
  • 4SM shall issue/display a license key and proceed to write out a chequered image
  • tmnov.lic text file: you can now read the tmnov.lic text file that is now displayed on your gedit text editor window.
Just try it, get the feeling!
(then don't forget to remove the .../no/... request for plain modeling)

Comparison with NOAA's
RLN method of ratio ln(Lblue)/ln(Lgreen)

The purpose is to compare
  • NOOA's method operated in 4SM RLNmode
  • with 4SM method in PANmode
As we have estimated spectral La, it is possible to operate NOAA's method where
  • Z=bias+slope*ln(Lsblue-Lablue)/ln(Lsgreen-Lagreen)
Slope : in 4SM slope is #1.0, no babbling!
  • this is because all BOA radiances are normalized to the range 0-200
Bias : it is to be estimated against some seatruth
  • in 4SM, we regress ZRLN against Z3 -which is taken to be seatruth-,
    • and adjust the bias as desired
  • depths over very brigher bottoms can only be overestimated  in Stumpf's  method
  • depths over very darker  bottoms can only be underestimated in Stumpf's  method
  • then what if the seatruth dataset does not represent the whole depth range over the whole bottom brightness range in a fair way?
  • For RLN modeling
    • -Z/MSL0.00/RLN_0.96_21.5/n_1/RLBgb1.220/mask_4
      • this disables the PANmode and enables the RLNmode
    • Enable the RLN mode and run the script
      • parameters are: bias Mzero=0.96 and slope Mone=21.5
      • they are set manually using a sea-truth regression or -ProfileAB/R/...
      • Lm threshold parameter is enforced: only pixels with Lr[2]>=Lm[2] are modeled.
      • tide correction is automatically disabled in RLNmode
  • For RLN seatruth regression
    • -RegressZZv/p/seatruth*depth_points_reproject_pruned/ZM/2_3/0_201/0_30_2.0/*
    • and run the script
      • See a comparison of the two methods; scatter plot compares computed depths
      • I obtained these results in 2003

Profile 2
  • -Z/MSL0.00/RLN_0.96_23.0/n_1/RLBgb1.220/mask_4 
  • -ProfileAB/R/profile_2/ZM/Reg_2_3/0_201/0_30_2.0/*   
Is'n't thhat nice!
This regression compares
X axis : Z computed in PAN mode
Y axis : Z computed in RLN mode

  Profile 2
  • -Z/MSL0.00/RLN_0.96_23.0/n_1/RLBgb1.220/mask_4 
  • -ProfileAB/R/profile_2/ZM/Reg_2_3/0_201/0_30_2.0/*   
Is'n't that nice!
This profile compares
RED  : Z computed in PAN mode
BLUE : Z computed in RLN mode

We know from seatruthing that the PAN mode is correctly calibrated
But the above results in RLN mode are obtained
  • using only the PANmode calibration
  • without any use of field data
  • without propper atmospheric correction or calibration in physical units of BOA reflectance


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