• Abstract
• Survey Outline
• Geodetic Control
• Data Processing
• Survey Results
• Data Tables
• Figures
• Acknowledgments
• References
• Appendix
• USGS Related Links
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Bathymetry and Acoustic Backscatter—Estero Bay, California

Geodetic Control

Geodetic control for the survey was established using the IN-Fusion SmartBase feature in the Applanix Position and Orientation System Post-Processing Package Mobile Mapping Suite (POSPac MMS, Version 6.1.4553.15282). IN-Fusion SmartBase is a feature in POSPac MMS that provides inertially aided, carrier-phase differential GNSS for mobile mapping platforms without requiring dedicated base receivers (Applanix, 2012). The software automatically selects a network of permanent GNSS reference stations accessible through the Internet and provides reference receiver coverage over the entire project area. The network of reference stations selected by the software changed slightly each day depending on the exact location of the survey vessel and the quality of the reference station data for the selected day. However, the network usually consisted of the stations shown in table 2, which ranged in distance from the survey area from about 11 km (6.8 mi) to more than 100 km (62 mi). Most of these reference stations were GPS-only, so only the GPS satellite network was used for final processing.

POSPac MMS processing combines the inertial motion data from the Applanix IMU with inertially aided kinematic ambiguity resolution (IAKAR) GNSS position data to produce a smoothed best estimate of trajectory (SBET) file which can then be used to position and orient the sonar data. The output reference frame of the SBET file is the World Geodetic System 1984 (G1150), with heights measured relative to the WGS84 (G1150) ellipsoid.