Mosaic of 5 m gridded multibeam bathymetry and bathymetry derived from multispectral IKONOS satellite imagery of Alamagan Island, Commonwealth of Northern Mariana Islands, USA

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). Eight derived products, four from the image alamagan_107146_msi_rat.pix (Ala146) and four from the image alamagan_135475_msi_rat.pix (Ala475), were integrated to expand spatial coverage. The original MLR variables for Ala146 were Yint=15.1542, Mblue=-10.3798, and Mgreen=24.3859. The product derived from these variables (Ala146_DB) was mosaiced with three additional products derived using increasingly reduced Y-intercept values as follows: Yint=11.1542 (Ala146_DB4), Yint=7.1542 (Ala146_DB8), Yint=3.1542 (Ala146_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 Ala475 were Yint=12.0276, Mblue=-6.3664, and Mgreen=16.1327. The product derived from these variables (Ala475_DB) was mosaiced with three additional products derived using increasingly reduced Y-intercept values as follows: Yint=8.0276 (Ala475_DB4), Yint=4.0276 (Ala475_DB8), Yint=0.0276 (Ala475_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 the data from Ala146 over Ala475. 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 (Ala_DBall) was then resampled to a 5 meter grid and integrated with 5m resolution multibeam sonar data, with sonar data prioritized over the derived data, to create the final product (Ala_DBMB_5m). 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.