laparguera-20131227-2

Depth Retrievals along Green Profile
PAN solution is a confirmed substitute to the GREEN solution
PAN solution vs GREEN solution

Profile Green LIDAR backdrop	Segment D deeper than ~5-10m, depths are badly underestimated Segment C depths are well estimated along the whole segment Segment B depths are badly underestimated from B1 to B2 Segment A depths are well estimated in the 0-15 m depth range
PAN solution Modeling by the "PAN solution" The RED profile shows LIDAR depth seatruth QUITE REMARKABLY, THE PAN BAND IS NOT NOISY HERE	GREEN solution Modeling by the "GREEN solution" The RED profile shows LIDAR depth seatruth PAN and GREEN solutions yield approximately the same depth retrieval
GREEN vs PAN solution PAN and GREEN solutions yield approximately the same depth retrieval Minute differences allow for spectral features to appear that the GREEN solution cannot reveal	GREEN vs PAN solution Minute differences allow for spectral features to appear that the GREEN solution cannot reveal
ZGREEN-ZPAN over ROI 2 at 15-25 m	ZGREEN-ZPAN over ROI 5 at depths 0-10 m This shows that differences are mostly of +/-a few tens of centimeters, but can reach +/-a few tens of decimeters therefore, using the PAN solution in place of the GREEN solution yields a spectral bottom signature which is more contrasted, as illustrated below this can only increase the potential for spectral bottom typing I look forward to pan-sharpenned version of such processing
This confirms that the PAN solution is trustworthy to considerable advantage

Water column correction

TCC deglinted, smoothed, water column corrected and normalized FOUL: areas badly affected by foul waters show in purple hues this is an indication that water clarity in the blue range have been badly overestimated Vegetation: areas which exhibit a greenish bottom signature show in green hues, likely bottom vegetation Coral sand: bright areas are possibly to be coral sands	TCC deglinted, not smoothed, water column corrected no smoothing here
TCC deglinted, not smoothed, and water column corrected LEFT: the dynamic range 0-250 of the scaled image has been applied to the shallow water column corrected bottom signatures, TOA details are obscured over bright areas RIGHT: the dynamic range 0-250 of the scaled image has been halved to the shallow water column corrected bottom signatures, TOA this reveals fine details over bright areas

Seatruth

ZLIDAR - Z4SM

RED: underestimated depth retrievals
BLUE: overestimated depth retrievals
LIGHT tones: whether blue or red, signal more acceptable depth retrievals

A tolal failure?

Some nice seatruth regressions from 0 to 25 m
and some not so nice
NO SMOOTHING
This proves that the simplified RTE is trustworthy the way it is operated in 4SM

ROI 2 at 15-25 m this is over the western deep outer ridge	ROI 4 at 2-7 m this is over the western part of La Parguera Marine Reserve, where W. Hernandez calibrated his work
ROI 1 at 4-13 m	ROI 3 at 3-16 m
ROI 5 over La Parguera Marine Reserve	ROI 6

ZLIDAR

TCC water column corrected
LIDAR depths have been applied/forced here

ZLIDAR - Z4SM
RED is where
4SM underestimated the bottom depth

LIDAR depths have been applied/forced here

this allows us to visualize where water column correction forces unrealistic bottom signatures
because/where the water leaving reflectance is significantly higher than assumed to be , then water column corrected signatures arespiked to the extent of the exponential of this artifact
what we see here is that the GREEN water leaving reflectance dominates
- therefore, we may conclude that chlorophyll content is the main source of our problems
- as reported abundantly in the litterature on SouthWest Puerto Rico.
where waters are true to the assumed OII water type, hues are dark and dull in this TCC rendition
where chlorophyll artifact is strongest, hues are brightest in this TCC rendition
- note that this mimics the ZLIDAR-Z4SM image