work updated april 2008
-WL467/508/523/535/544/554/565/574/585/595/644/845 in nanometers
Unfortunately, this dataset lacks bands in the red-to-green region of the solar spectrum.
Only one blue band.
This does not help for an optimal deglinting, and also for calibrating/modeling.
Lucky that we have one NIR band!
The best calibration of CASI data I have seen to-date, april 2008 with 4SM.2.06.
Lots of clean bright sands here, at all depths.
I wish I was given the chance of a proper 4SM work on this dataset:
starting from raw flightlines, myself on my own machine.
Some cleaning/preprocessing of raw data |
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![]() Computed Depth image_Z250 image_Z250 modal filtered image_wZ: depth is computed down to ~15 m | Average Bottom Reflectance image_B mostly extermely dark bottoms |
![]() Color composite of the "water column corrected" image_LBS | ![]() Histogram equalization of image_LBS helps to see throuh |
![]() ![]() Negative bottom contrast abound | ... a real challenge for modeling! ![]() ![]() Negative bottom contrast abound |
Now we can run ![]() a bottom type classification in 4SM as of april 2008 This was done in 4SM without any access to seatruth, including a final modal filtering Under such adverse conditions, the equalization has been a real challenge. Too bad the deglinting was not able to clean properly the heavy sun glint. Flying into or away from the sun would have been advisable indeed in view of shallow water work! |
23 bottom types are mapped: mostly three famillies of bottom types:
| STATISTICS OF SHALLOW BOTTOM TYPING BOA radiance 0-200 on Tue Apr 29 06:21:54 2008
Type_0 is Land pixel Type_1 is Unclassified Shallow pixel Type_2 is Optically Deep water pixel Type_3 is No Data pixel Type_4 is Wave Breaker pixel Type_5 is Cloud/Shadow pixel 1.05% as type_1, i.e. Shallow_pixel_NOT_Classified 2.27% as type_6 SIG 163.7 168.5 179.6 167.7 166.6 164.2 165.0 168.6 163.4 167.1 169.7 167.6 BGSL_168 SD_5.3 STD 12.3 8.8 8.1 7.9 8.2 8.0 8.1 8.8 7.8 9.7 9.8 9.4 3.41% as type_7 SIG 145.6 155.3 170.4 162.0 163.2 162.5 164.6 170.4 160.3 159.8 148.3 155.9 BGSL_156 SD_2.5 STD 3.6 3.7 4.3 4.1 3.9 4.1 3.8 4.8 4.0 4.0 3.7 3.6 5.33% as type_8 SIG 89.7 109.4 118.0 105.5 103.5 100.3 101.3 105.5 102.4 105.5 97.0 102.0 BGSL_102 SD_3.3 STD 3.5 3.7 3.8 3.3 3.2 3.0 3.0 3.1 3.2 3.3 3.8 3.5 1.90% as type_9 SIG 74.6 95.0 103.6 93.2 92.5 89.8 91.5 94.8 91.2 92.0 81.8 88.2 BGSL_88 SD_3.5 STD 3.3 3.3 3.5 3.1 3.0 2.9 2.9 2.8 2.9 3.1 3.4 3.1 2.88% as type_10 SIG 67.1 83.9 92.3 83.4 82.4 80.3 81.4 86.2 82.5 83.6 72.9 78.6 BGSL_79 SD_4.1 STD 3.4 3.6 3.8 3.3 3.0 3.0 3.0 3.2 3.1 3.3 3.4 3.4 7.54% as type_11 SIG 44.9 51.2 57.6 55.8 57.8 57.6 60.4 61.3 55.3 51.8 47.6 51.4 BGSL_51 SD_8.5 STD 3.3 4.2 4.8 4.6 4.6 4.8 4.8 4.9 4.5 4.3 3.7 4.0 8.75% as type_12 SIG 27.7 25.3 28.6 27.4 28.4 28.4 29.9 31.7 28.7 28.3 26.1 27.3 BGSL_27 SD_7.7 STD 1.6 2.1 2.3 2.2 2.3 2.3 2.3 2.4 2.3 2.1 1.8 2.0 3.81% as type_13 SIG 16.0 18.6 21.1 18.4 19.4 19.2 20.8 21.8 20.1 19.6 16.2 18.1 BGSL_18 SD_5.4 STD 1.0 1.0 1.1 1.0 1.0 0.9 1.0 1.0 1.0 0.9 1.0 1.0 13.31% as type_14 SIG 39.3 32.3 35.2 32.9 34.3 33.3 36.5 36.0 35.2 35.5 35.4 35.4 BGSL_35 SD_12.5 STD 4.5 4.4 4.5 4.1 4.4 4.5 4.9 4.5 4.7 4.4 4.4 4.4 18.68% as type_15 SIG 22.0 19.0 20.0 16.7 16.8 16.2 16.9 18.1 17.1 18.7 19.9 19.5 BGSL_20 SD_14.5 STD 3.3 2.9 3.2 2.9 2.7 2.5 2.4 2.7 2.8 3.2 2.8 3.0 8.09% as type_16 SIG 18.6 11.7 14.2 13.3 15.1 13.1 17.1 14.7 15.0 15.0 15.0 15.0 BGSL_15 SD_6.6 STD 1.4 0.9 0.9 0.9 1.0 0.9 1.2 0.9 0.9 0.9 0.9 0.9 8.19% as type_17 SIG 16.8 9.4 11.4 10.7 11.8 11.1 13.7 12.9 12.7 12.7 12.7 12.7 BGSL_13 SD_5.6 STD 0.8 0.7 0.8 0.7 0.7 0.7 0.6 0.7 0.7 0.7 0.7 0.7 3.05% as type_18 SIG 9.1 4.5 5.1 6.2 6.4 5.8 8.9 9.4 8.3 4.4 6.6 6.6 BGSL_7 SD_12.1 STD 0.8 0.8 0.9 0.7 0.8 0.7 0.8 0.8 1.0 0.8 0.8 0.8 5.76% as type_19 SIG 13.2 0.8 3.1 2.7 5.1 4.1 8.1 7.2 3.9 6.1 6.1 6.1 BGSL_6 SD_17.4 STD 1.8 0.5 0.9 0.9 1.2 1.0 1.5 1.1 1.0 1.1 1.1 1.1 4.18% as type_20 SIG 8.2 2.0 3.3 3.7 5.1 5.0 7.4 7.4 5.3 3.3 5.0 5.0 BGSL_5 SD_27.5 STD 1.3 1.2 1.6 1.4 1.5 1.5 1.7 1.6 1.5 1.4 1.3 1.3 1.09% as type_21 SIG 4.4 3.1 4.7 2.6 4.3 3.7 6.2 5.4 3.8 1.1 3.9 3.9 BGSL_4 SD_10.7 STD 0.2 0.4 0.5 0.4 0.4 0.4 0.5 0.5 0.6 0.5 0.3 0.3 0.39% as type_22 SIG 4.3 3.5 3.9 1.5 2.9 2.1 4.3 3.4 3.4 3.4 3.4 3.4 BGSL_3 SD_8.3 STD 0.2 0.2 0.3 0.3 0.3 0.2 0.2 0.5 0.5 0.5 0.5 0.5 0.33% as type_23 SIG 9.3 0.5 0.4 2.2 2.3 1.3 4.3 4.9 3.4 4.0 4.0 4.0 BGSL_4 SD_5.6 STD 0.4 0.2 0.3 0.2 0.3 0.3 0.2 0.3 0.3 0.1 0.1 0.1 |
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| | 23 bottom type | | ||
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