Sidescan sonar data processing and mosaic steps using SonarWiz6:
1. Create a project (UTM-WGS84, Zone 19N, central meridian -69.0) and use all default import parameters for the Humminbird .DAT format in SonarWiz6 (use sensor heading, import 1024 samples per channel, channels 1 and 2).
2. Once the .DAT file is imported, select the file (right click) and set the processing options (settings): Enable EGN (empirical gain normalization using all sidescan sonar data pixel values and range from transducer), intensity 75; enable Nadir Filter, nadir angle 40; project sonar data using sensor heading checkbox selected.
3. After the processing settings are applied, select the sonar file (right click) and set the display range for port and stbd to 15 meters.
4. Then single click on the sonar file and set the color histogram datatype to sidescan (ch. 1 and 2), palette to gray, inverted, and manually stretched values of 79-149.
5. After processing completes, use the Export menu to save individual geo-images. In the resulting popup dialog, set the output file type to GeoTIFF, color resolution 24-bit, image resolution 1 meter/pixel, background color to white (255,255,255), checkbox selected for disable compression. The resulting GeoTIFF image is spatially mapped in the UTM 19N WGS84 projection.
6. Reproject the GeoTIFF created in step 5 from UTM zone 19N WGS84 to UTM zone 19N NAD83-HARN using the ArcCatalog Project Raster utility. The output horizontal datum used is NAD_1983_HARN_UTM_Zone_19N.