binPPK

Description

binPPK is a utility designed to convert ASCII PPK (Post-Processed Kinematic) data, typically exported from software like TGO (Trimble Geomatics Office), into a custom binary format. This binarization streamlines the data for subsequent processing, such as merging with other datasets using tools like merge_PPK.

The tool reads date, time, latitude, longitude, and height from an ASCII input file and writes it to a binary file, performing byte-swapping for portability.

Usage 

binPPK <asciiPPKfile> <binaryPPKfile> [-v]

Arguments

Option Description
<asciiPPKfile> Required. The path to the input ASCII PPK data file.
<binaryPPKfile> Required. The path for the output binary PPK file.
-v Enable verbose output.

How It Works

  1. File Opening: Opens the input ASCII file for reading and the output binary file for writing (wb+).
  2. Data Structure: Defines a PPK_structure to hold time (Unix timestamp), latitude, longitude, and height.
  3. Line-by-Line Processing: Iterates through each line of the ASCII input file:
    • Parsing: Reads hour, min, sec, day, mon, year, lat, lon, and height from the current line using fscanf.
    • Timestamp Conversion: Converts the date and time components into a Unix timestamp (seconds since 1970) using stdtime_from_dmy.
    • Data Validation: Performs basic checks:
      • If the absolute time difference between the current and previous record is greater than 20 seconds, it prints a warning.
      • If the absolute height difference is greater than 1.0, it prints a warning.
      • Note: These checks are for warnings only and do not stop processing the record.
    • Binary Writing (ppk_write): If the data is deemed acceptable (not strictly filtered by the warnings), it writes the PPK_structure data to the binary output file at an offset determined by recordnum * PPK_RECLEN. The ppk_write function uses put_swapped_int and put_swapped_float to handle byte-swapping, ensuring platform compatibility.
  4. Cleanup: Closes both input and output files.

Output Files

  • <binaryPPKfile>: A custom binary file containing PPK data.

Helper Functions

  • interp_ppk(): (Currently commented out in main but present) This function is designed to interpolate height values between two PPK records over a time gap, if a significant time gap and height difference exist.
  • ppk_write(): Writes a PPK_structure to the binary file at a specified record number, handling byte-swapping.
  • show_date_calc(): A debugging function to display date conversions.

Dependencies

  • support.h: For utility functions.
  • stdtime.h: For time conversion.
  • jb_endian.h: For byte swapping.

Notes

The binary PPK format created by this tool is optimized for fast reading and processing by other internal tools within the OMG ecosystem. The explicit byte-swapping ensures portability across different system architectures. The data validation checks provide basic quality control during conversion.