rationalOMG

Description

rationalOMG is an interactive command-line utility for exploring the contents of an OMG-HDCS merged data file in a “rationalized” format. It allows users to view summary information, and then interactively query specific profile (ping) records and their associated beam data. It can also display raw sidescan traces if available.

The “rationalized” format means that the data is presented in a more human-readable and processed form, as opposed to the raw binary storage format.

Usage 

rationalOMG <OMG_HDCS_datafile> <ASCII_listing> [OPTIONS]

Arguments

Option Description
<OMG_HDCS_datafile> Required. The path to the input OMG-HDCS merged data file.
<ASCII_listing> Required. The path to the ASCII output file where information will be written.
-coeffs (Not implemented in the provided code) This option is present in the USAGE string but its functionality is not seen in the main function. It might be intended to display coefficients.
-tidecor Enables the use of tide correction (sets use_tide_corr_flag).
-traces Enables the retrieval and display of raw sidescan traces associated with each beam. This requires a .ss_data file alongside the merged file.
-v Enable verbose output (not explicitly used in main for display, but often a general verbose flag).

Interactive Mode

The tool provides an interactive prompt “give profile no#” allowing users to:

  • Enter a specific profile (ping) number to view.
  • The tool will then display the profile header details (e.g., latitude, longitude, heading, tide, sample rate) and detailed beam data (status, position, depth, across-track, TWTT, beam angle, beam azimuth).
  • If -traces is enabled, it also displays the raw sidescan data (pixel values) for each beam.

How It Works

  1. File Opening: Opens the specified OMG-HDCS merged data file and an ASCII output file. If -traces is enabled, it also attempts to open an associated .ss_data file.
  2. Summary Display: Reads and prints a “rationalized” summary of the merged file, including the number of profiles and the geographic extents (min/max latitude/longitude).
  3. Interactive Profile Query: Enters an infinite loop, prompting the user for a profile number:
    • The user enters a profile number.
    • The tool reads the “rationalized” profile header for that profile number, including ping latitude/longitude, heading, tide, and sample rate, and prints it to the console.
    • It then retrieves the “rationalized” beam data for all beams within that profile.
    • For each beam, it prints detailed information including status, position (latitude/longitude), depth, across-track, TWTT (Two-Way Travel Time), beam angle, and beam azimuth.
    • If -traces is enabled, it also prints the number of samples, center number, and then the raw 8-bit sidescan data values for each sample in the beam.
    • After displaying the information for the requested profile, it loops back to prompt for another profile number.

Output Files

The tool primarily outputs data to the console in its interactive mode and writes a summary and detailed information to the specified <ASCII_listing> file.

Dependencies

  • OMG_HDCS_jversion.h: For OMG-HDCS data structures and rationalized reading functions (OMG_HDCS_read_rationalized_profile, OMG_HDCS_read_rationalized_beams).
  • support.h: For general utility functions and error handling.

Notes

The “rationalized” data means that the values are converted from their internal storage format (e.g., scaled integers) into standard engineering units (e.g., degrees, meters, seconds) and are directly related to physical measurements. This makes the output easier to interpret for analysis and debugging. The tool is interactive, so it pauses for user input.