ZC vs ZR regression by 4SM method

ZZRegressor: Statistics of seatruth ZC-ZR on image waimanalowv2m_deg at Oahu, Hawaii N=5.589 millions pixels by Morel's 4SM method HTide=1.00 Smooth=1_5 Using_bands_1_2_3_4_5 cZ=1.00  1.89% pixels with depth underestimated by more than 5.0 m 4.26% pixels with depth underestimated by more than 3.0 m 6.31% pixels with depth underestimated by more than 2.0 m 15.18% pixels with depth underestimated by more than 1.0 m 31.12% pixels with depth underestimated by more than 0.0 m 23.91% pixels with depth  overestimated by less than 1.0 m 10.80% pixels with depth  overestimated by less than 2.0 m 4.56% pixels with depth  overestimated by less than 3.0 m 1.61% pixels with depth  overestimated by less than 5.0 m 0.37% pixels with depth  overestimated by more than 5.0 m 55.03% of computed depths are within  +-1.0 m of DTM depth 81.00% of computed depths are within  +-2.0 m of DTM depth 91.86% of computed depths are within  +-3.0 m of DTM depth 97.74% of computed depths are within  +-5.0 m of DTM depth over a total of 100.00% of computed depths

Final water column corrected image    some locations of AOI targets are shown

July 24th: Final classified image: 15 classes

Bottom Typing is an art: no ISODATA here!

Bottom types 10 to 14 : possibly sandy areas


Bottom types 15 to 18 : possibly hard substrates with scattered corals
 
 
Bottom types 31 to 35 : probably dense coral constructions

 

STATISTICS OF ALL SHALLOW BOTTOM TYPING: BOA radiance 0-200 for waimanalowv2m_deg WV02 image
 CoefSIG=1.00 nbMISS=0 sizeXY=9248668 -E1/3289/430/3241  on Tue Jul 24 17:53:21 2012
 SIGnbMax=35
            1460484 pixels in Type_0:   15.791% Land area
                  0 pixels in Type_1:    0.000% Unclassified Shallow bottoms
            1697202 pixels in Type_2:   18.351% Optically Deep water
                183 pixels in Type_3:    0.002% No Data area
                  0 pixels in Type_4:    0.000% Wave Breaker area
                  0 pixels in Type_5:    0.000% Cloud/Shadow area
            13667260 pixels in Type>5:  147.775% Classified Shallow bottoms

4559655 pixels  49.301% in type_15 B= 67.5
2076937 pixels  22.457% in type_17 B= 56.3
1775961 pixels  19.202% in type_14 B= 94.8
1630931 pixels  17.634% in type_13 B=101.5
1034929 pixels  11.190% in type_18 B= 50.8
 691391 pixels   7.476% in type_31 B= 46.4
 645851 pixels   6.983% in type_11 B=124.5
 331064 pixels   3.580% in type_33 B= 39.7
 265349 pixels   2.869% in type_10 B=151.7
 215178 pixels   2.327% in type_34 B= 35.6
 176448 pixels   1.908% in type_12 B=114.7
 135054 pixels   1.460% in type_35 B= 33.6
 128512 pixels   1.390% in type_32 B= 37.6

July 25th

• This allows to optimize the computed depth according to the estimated bottom type at each pixel
  • this is akin to a Spectral Library approach 
• This tends to add undesirable noise to the depth image,
  • which, for now, makes it unsuitable for display
• But it solves some of the major inconsistencies,
  • as evidenced by the new ZC-ZR image
• Overall, this appears to roughly conserve the precision of computed depth:
  • 81.00% of computed depths are within  +-2.0 m of DTM depth  (was 83% in the July 5th image)
• this brand new trick seems to be promising,
  • needs to be further tested and augmented
  • would greatly benefit from many more bottom type signatures

bottom typing in 4SM is an art: no ISODATA here!

   
July 5th                                                                          July 25th