Multiple tools in ENVI 4.5 were used to complete the following
processing steps: Data conversion from digital number to radiance,
correction for atmosphere and water surface reflection,
linearization of spectral decay as function of depth, masking of
non-applicable values, and bathymetric derivation using variables
from multiple linear regression analysis. Multiple tools in
ArcGIS 9.3 were used for dataset integration and to extract values
for the multiple linear regression analysis and subsequent error
analyses. The statisitcs program S-Plus was used for the multiple
linear regression analysis to provide original variables for depth
derivation. The multivariate slope intercept formula used to
derive depth was Depth=Yint+(Mblue)(Xblue)+(Mgreen)(Xgreen). Seventeen derived
products, four from the image otutu_msi_61091.img (Tut091), two from the
image otutu_msi_60736.img (Tut736), four from the image otutu_msi_65904.img
(Tut904), three from the image otutu_msi_65907 (Tut907) and four from the image
otutu_msi_65909.img (Tut909), were integrated to expand spatial coverage.
The original MLR variables for Tut091 were Yint=19.7602, Mblue=-1.6871, and
Mgreen=12.3928. The product derived from these variables (Tut091_DB) was mosaiced
with three additional products derived using increasingly reduced Y-intercept values
as follows: Yint=15.7602 (Tut091_DB4), Yint=11.7602 (Tut091_DB8), Yint=7.7602
(Tut091_DB12). This was done to increase coverage in shallow areas. More information
on this integration process is provided in the product error analysis, availble from
PIBHMC upon request.
The original MLR variables for Tut736 were Yint=-4.3919, Mblue=-8.6422, and
Mgreen=12.2726. The product derived from these variables (Tut736_DB) was mosaiced
with one additional product (Tut736_DB4) with a decreased Y-intercept value of -8.3919.
This was done to increase coverage in shallow areas. More information
on this integration process is provided in the product error analysis, availble from
PIBHMC upon request.
The original MLR variables for Tut904 were Yint=2.8541, Mblue=-18.3048, and
Mgreen=25.7446. The product derived from these variables (Tut904_DB) was mosaiced
with three additional products derived using increasingly reduced Y-intercept values
as follows: Yint=-1.1459 (Tut904_DB4), Yint=-5.1459 (Tut904_DB8) and Yint=-9.1459
(Tut904_DB12). This was done to increase coverage in shallow areas. More
information on this integration process is provided in the product error analysis,
availble from PIBHMC upon request.
The original MLR variables for Tut907 were Yint=-5.4039, Mblue=-13.7452, and
Mgreen=18.3747. The product derived from these variables (Tut907_DB) was mosaiced with
two additional products derived using increasingly reduced Y-intercept values as follows:
Yint=-9.4039 (Tut907_DB4), Yint=-13.4039 (Tut907_DB8). This was done to increase coverage
in shallow areas. More information on this integration process is provided in the product
error analysis, availble from PIBHMC upon request.
The original MLR variables for Tut909 were Yint=17.1093, Mblue=-1.2295, and
Mgreen=11.0006. The product derived from these variables (Tut909_DB) was mosaiced
with three additional products derived using increasingly reduced Y-intercept values
as follows: Yint=13.1093 (Tut909_DB4), Yint=9.1093 (Tut909_DB8) and Yint=5.1093
(Tut909_DB12). This was done to increase coverage in shallow areas. More
information on this integration process is provided in the product error analysis,
availble from PIBHMC upon request.
The derived bathymetry from each image was in turn mosaiced prioritizing image data in the
following order (highest to lowest): Tut091, Tut909, Tut907, Tut736 and Tut904. Data with
better statistical accuracy was given higher "priority" so that they replaced concurrent
data with lower accuracy during the mosaic process.
This mosaiced derived bathymetry product (Tut_DBall) was then resampled to a 5 meter
grid and integrated with the multibeam sonar data, with sonar data prioritized over the
derived data, to create the final product (Tut_DBMB).
A detailed description of all processing steps is available at:
http://dusk.geo.orst.edu/djl/theses/kyle/Cookbook_042108.pdf
An error analysis of each derived bathymetry grid used is available
upon request.
