8k2omg

Description

8k2omg is a utility designed to convert older Reson SeaBat 8000 series data (.81x files) into the OMG-HDCS (Ocean Mapping Group - Hydrographic Data Conversion System) merged file format. It extracts bathymetry and snippet data from the .81x files and maps them to the corresponding structures in the OMG-HDCS format.

This tool provides a bridge for older Reson data to be processed and integrated within the modern OMG toolkit. It handles various aspects of the conversion, including time synchronization, quality flags, and basic sonar calibration parameters.

Usage 

8k2omg -81x <input_name> -omg <omg_prefix> [-v] [-debug] [-ER]

Arguments

| Option | Description | |—|—| | -81x <input_name> | Required. Path to the input Reson SeaBat 8000 series (.81x) file. | | -omg <omg_prefix> | Required. Prefix for the output OMG-HDCS files. The tool will generate: * <omg_prefix>.merged: The main OMG-HDCS merged file. * <omg_prefix>.merged.ss_data: Snippet side-scan data. | | -v | Enable verbose output. | | -debug | Enable debug output. | | -ER | Indicates an Extended Range projector (affects source level calculation). |

How It Works

  1. Initialization: Parses command-line arguments, setting input/output filenames and various flags (e.g., verbose, debug, extended_range). Initializes Reson 8000 series data structures (RESON_PEEKER, RESON_BATHY, RESON_SNIPPET, SNP1) and OMG-HDCS structures (OMG_HDCS_summary_header, OMG_HDCS_profile_header, OMG_HDCS_beam).
  2. File Opening: Opens the input .81x file for reading. Creates the output OMG-HDCS merged file (.merged) and snippet data file (.merged.ss_data).
  3. Initial Bathy Record Scan: Performs a preliminary scan to find the first valid bathymetry record, which is used to initialize the OMG_HDCS_summary_header (e.g., sonar_type, base_time, refTime).
  4. OMG Summary Header Initialization:
    • Determines sonar_type based on bathy.sonar_model.
    • Initializes an OMG_HDCS_summary_header structure, setting fileVersion, toolType, refTime, numDepths, etc.
    • Writes this summary header to the .merged file.
    • Allocates memory for OMG_HDCS_beam structures.
  5. Record Processing Loop: Rewinds the input .81x file and processes it record by record:
    • Sync Search: Calls seek_next_8K_sync() (an external function) to find the next Reson 8k synchronization pattern.
    • Record Type Identification: Reads RESON_PEEKER to determine the packet type (Bathy or Snippet).
    • Data Reading:
      • If it’s a Bathy record (RESON_8K_SYNC_PATTERN), reads RESON_BATHY data (bathy).
      • If it’s a Snippet record (SNIPPET_ID_SNP0), reads RESON_SNIPPET data (snippet).
    • Ping Matching: Continues until a Bathy record and a Snippet record with matching ping_number are found.
    • OMG Profile Header Population: Populates an OMG_HDCS_profile_header structure from the bathy data:
      • timeOffset is calculated relative to summary.refTime.
      • Sonar settings like samp_rate, power, TVG, pulseLength, rx_gain_reduction, tx_power_reduction, max_swath_width are set.
      • Source level (profile.params[0].txLevel) is estimated based on sonar_type and extended_range.
      • Projector beam width (profile.params[0].txBeamAngle) and projector angle (profile.params[1].txPulseLength) are set.
    • OMG Beam Structure Population: For each beam:
      • beams[i].range is set from bathy.range[i].
      • Preliminary beams[i].observedDepth and beams[i].acrossTrack are calculated using simplified geometry (angle derived from beam index, slant range from bathy.range[i]).
      • beams[i].status and beams[i].Q_factor are derived from bathy.quality[i].
      • beams[i].calibratedBackscatter and beams[i].reflectivity are derived from bathy.intensity.
      • Snippet Data Processing:
        • beams[i].centre_no, beams[i].no_samples are derived from bathy.range[i] and snippet data.
        • beams[i].offset is set to the current file pointer in outfile_snippets.
        • Snippet samples are written to outfile_snippets.
        • beams[i].reflectivity is recalculated from the average snippet amplitude.
    • Write to Merged File: OMG_HDCS_write_profile() and OMG_HDCS_put_raw_beams() write the populated profile header and beam data to the .merged file.
  6. Cleanup: Closes all open files and frees allocated memory.

Output Files

  • <omg_prefix>.merged: Standard OMG-HDCS merged file.
  • <omg_prefix>.merged.ss_data: Snippet side-scan data (binary, raw short intensities). ``` — layout: default title: 8k2omg parent: Reson Tools nav_order: 182 —

    8k2omg

Description

8k2omg is a utility designed to convert older Reson SeaBat 8000 series data (.81x files) into the OMG-HDCS (Ocean Mapping Group - Hydrographic Data Conversion System) merged file format. It extracts bathymetry and snippet data from the .81x files and maps them to the corresponding structures in the OMG-HDCS format.

This tool provides a bridge for older Reson data to be processed and integrated within the modern OMG toolkit. It handles various aspects of the conversion, including time synchronization, quality flags, and basic sonar calibration parameters.

Usage 

8k2omg -81x <input_name> -omg <omg_prefix> [-v] [-debug] [-ER]

Arguments

| Option | Description | |—|—| | -81x <input_name> | Required. Path to the input Reson SeaBat 8000 series (.81x) file. | | -omg <omg_prefix> | Required. Prefix for the output OMG-HDCS files. The tool will generate: * <omg_prefix>.merged: The main OMG-HDCS merged file. * <omg_prefix>.merged.ss_data: Snippet side-scan data. | | -v | Enable verbose output. | | -debug | Enable debug output. | | -ER | Indicates an Extended Range projector (affects source level calculation). |

How It Works

  1. Initialization: Parses command-line arguments, setting input/output filenames and various flags (e.g., verbose, debug, extended_range). Initializes Reson 8000 series data structures (RESON_PEEKER, RESON_BATHY, RESON_SNIPPET, SNP1) and OMG-HDCS structures (OMG_HDCS_summary_header, OMG_HDCS_profile_header, OMG_HDCS_beam).
  2. File Opening: Opens the input .81x file for reading. Creates the output OMG-HDCS merged file (.merged) and snippet data file (.merged.ss_data).
  3. Initial Bathy Record Scan: Performs a preliminary scan to find the first valid bathymetry record, which is used to initialize the OMG_HDCS_summary_header (e.g., sonar_type, base_time, refTime).
  4. OMG Summary Header Initialization:
    • Determines sonar_type based on bathy.sonar_model.
    • Initializes an OMG_HDCS_summary_header structure, setting fileVersion, toolType, refTime, numDepths, etc.
    • Writes this summary header to the .merged file.
    • Allocates memory for OMG_HDCS_beam structures.
  5. Record Processing Loop: Rewinds the input .81x file and processes it record by record:
    • Sync Search: Calls seek_next_8K_sync() (an external function) to find the next Reson 8k synchronization pattern.
    • Record Type Identification: Reads RESON_PEEKER to determine the packet type (Bathy or Snippet).
    • Data Reading:
      • If it’s a Bathy record (RESON_8K_SYNC_PATTERN), reads RESON_BATHY data (bathy).
      • If it’s a Snippet record (SNIPPET_ID_SNP0), reads RESON_SNIPPET data (snippet).
    • Ping Matching: Continues until a Bathy record and a Snippet record with matching ping_number are found.
    • OMG Profile Header Population: Populates an OMG_HDCS_profile_header structure from the bathy data:
      • timeOffset is calculated relative to summary.refTime.
      • Sonar settings like samp_rate, power, TVG, pulseLength, rx_gain_reduction, tx_power_reduction, max_swath_width are set.
      • Source level (profile.params[0].txLevel) is estimated based on sonar_type and extended_range.
      • Projector beam width (profile.params[0].txBeamAngle) and projector angle (profile.params[1].txPulseLength) are set.
    • OMG Beam Structure Population: For each beam:
      • beams[i].range is set from bathy.range[i].
      • Preliminary beams[i].observedDepth and beams[i].acrossTrack are calculated using simplified geometry (angle derived from beam index, slant range from bathy.range[i]).
      • beams[i].status and beams[i].Q_factor are derived from bathy.quality[i].
      • beams[i].calibratedBackscatter and beams[i].reflectivity are derived from bathy.intensity.
      • Snippet Data Processing:
        • beams[i].centre_no, beams[i].no_samples are derived from bathy.range[i] and snippet data.
        • beams[i].offset is set to the current file pointer in outfile_snippets.
        • Snippet samples are written to outfile_snippets.
        • beams[i].reflectivity is recalculated from the average snippet amplitude.
    • Write to Merged File: OMG_HDCS_write_profile() and OMG_HDCS_put_raw_beams() write the populated profile header and beam data to the .merged file.
  6. Cleanup: Closes all open files and frees allocated memory.

Output Files

  • <omg_prefix>.merged: Standard OMG-HDCS merged file.
  • <omg_prefix>.merged.ss_data: Snippet side-scan data (binary, raw short intensities).