All soundings in the SHOALS* format are given a confidence value during acquisition. These confidence values are used to flag soundings during conversion so that soundings with certain confidence values are rejected. The following status flags are assigned to soundings. These can be changed in HIPS.
• Rejected by disabled beam: This flag rejects soundings with a negative confidence value.
• Rejected by depth gate: This flag is for soundings with confidence values that range from 0 to 70. The 0 to 50 range represents soundings where no bottom was found, and the 51 to 70 represents soundings of questionable confidence.
• Accepted: This flag is for soundings with confidence values from 71 to 99.
When converting to HIPS, all soundings with a confidence value less than the Confidence Cutoff Value will be automatically rejected. The default cut-off value is 70.
If the dataset contains land data, the topographic format (TOF) options can be set to convert this data also.
*(Scanning Hydrographic Operational Airborne LIDAR Survey)
Interface
The conversion options for SHAOLS data are set in this dialog box:
Procedure
1. Use the slider to set a different cut-off value.
2. Select either the First Pulse check box to convert the return from the top of the vegetation canopy or the Second Pulse check box to convert the return from the ground.
3. Click Next to continue the conversion process.