Python and shell scripts were used to reformat the navigation text files and add them to a geospatial SQLite (version 3.7.9) database. The processing flow for this step follows:
A. A Python script (pyReformatSidescanNav.py) was used to read and reformat CSV navigation files. The script reformatted each record to include the Julian Day (JD) with year and time, and it added fields for the survey line name, field activity number (2015-001-FA), survey vessel (M/V Scarlett Isabella) and the device used (Edgetech 4200).
B. A Python script (pySQLBSidescanNav.py) ran on each reformatted CSV file, parsing the file from each record and adding points to an SQLite database (which is created if it does not already exist). The pySQLSidescanNav script creates both point and trackline navigation for each survey line. This process populates attribute fields for the survey line ('LineName'), Year and Julian day ('Year_JD_init') survey line started, Julian day and UTC time ('JD_UTC_init') survey line started, Year and Julian day ('Year_JD_end') survey line ended, Julian day and UTC time ('JD_UTC_end') survey line ended, survey ID ('SurveyID'), survey vessel name ('VehicleID'), device used to collect the data ('DeviceID') and length field ('Length_km').
C. When all of the survey lines have been processed into SQLite database, a polyline shapefile is exported from the database using the spatialite_tool command (Spatialite version 3.0.1). Steps A and B were both run within a shell script called sonarwiznavconv.