# Nearshore Benthic Mapping in the Great Lakes:
## 3 Results  
### Classification Performance Analysis  
#### 3.1.1 Substrate Component Classification Results  
For the Tier 1 substrate component, there were a total of 24 airborne data combinations with an average overall accuracy of 90.10 \(\pm\) 0.60%, while there were a total of 12 satellite data combinations with an average overall accuracy of 89.77 \(\pm\) 1.02% (including data combinations with additional ROIs). In comparison, KCs were more moderate to low, averaging 0.47 (\(\pm\)0.08) for airborne data combinations and 0.30 (\(\pm\)0.03) for satellite data combinations. Table 11 (Appendix A) lists the percent overall accuracy and KC, as well as the percent area and producer and user accuracies for the three classes (coarse unconsolidated, fine unconsolidated, and anthropogenic) using airborne and satellite data combinations. The Index field in Table 11 (Appendix A) is a numerical value that is referenced in Figures 10-12 in which classification performance is plotted (percent overall accuracy compared to percent producer accuracy) to help illustrate patterns with respect to unique data combinations. Comparison of classification results is presented for each component by data type in the following sections. Figure 10: Tier 1 plot of coarse unconsolidated substrate classification performance, comparing percent overall accuracy and percent producer accuracy for airborne and satellite data combinations. Number labels refer to unique classification input data combinations identified in the Index field in Table 1, Appendix A.  
Figure 11: Tier 1 plot of fine unconsolidated substrate classification performance, comparing percent overall accuracy and percent producer accuracy for airborne and satellite data combinations. Number labels refer to unique classification input data combinations identified in the Index field in Table 1, Appendix A. In general, the classifications showed that the majority of the area had fine unconsolidated substrate with airborne data combinations estimating 92.51% (\(\pm\)1.91%) and satellite data combinations estimating a higher coverage amount of 98.35% (\(\pm\)1.02%). While the southern part of the study area consisted mostly of fine unconsolidated substrate, pockets of coarse unconsolidated substrate were observed primarily in the northern part of the study area, generally ranging from 0.3 to 0.7 km offshore (airborne data combinations estimated 4.69 \(\pm\) 0.56% versus satellite data combinations, which estimated approximately half that amount, 2.20 \(\pm\) 0.26%). Anthropogenic substrate was also found in central and northern parts of the study area, such as a nearshore breakwater, remnant road beds, structures, and debris (ranging from 0.1 to 0.2 km offshore), an intake pipeline (extending 0.9 km in length), a power plant water intake structure (0.75 km offshore), and two shipwcks (south of the central intake pipeline), with an overall total estimated cover of 3% (\(\pm\)1.04%) from airborne data combinations only. Satellite data were insufficient for classification of anthropogenic substrate (Figure 13; Table A1, Appendix A). Figure 12: Tier 1 plot of anthropogenic substrate classification performance, comparing percent overall accuracy and percent producer accuracy for airborne only data combinations. Number labels refer to unique classification input data combinations identified in the Index field in Table A1, Appendix A. Note that satellite classification of anthropogenic substrates is not included because the satellite inputs were insufficient for discriminating those features. The three airborne data combinations with the highest overall classification accuracies included the following (highest to lowest): (1) CA MNF FU, (2) CA MNF FU + CA MNF WLR (and reverse order), and (3) CA MNF WLR + CA MNF FU + AB DE (and reverse order). In general, for most of the top-performing airborne data combinations, data input order did not affect classification accuracy, and thus, combinations with the same data inputs performed the same regardless of order.