Analyzer for log files of time stations

This tool uses radio_datetime_utils and per-station libraries to analyze log files of these stations.

License

This work is licensed under "MIT OR Apache-2.0" Copyright 2023-2025 René Ladan rene0+codeberg@freedom.nl

Usage

The program takes a minimum of two parameters:

• the station name of the file to analyze (as argument to the -s option)
• the name of the file to analyze (as argument to the -f option)

The -h option provides a short help message.

The -u option shows the decoded date in time in UTC instead of local time. The "summer" and "winter" indicators are replaced by "UTC", information on DST transitions is still shown.

The -e indicates that the log file is a per-edge log file as sent over USB by rp-rs-radio-clock instead of a regular per-bit log file. When processing per-edge log files, the -E option can be used to adjust the spike limit in microseconds.

The -M option toggles the processing mode of the log file. The default mode is strict for per-edge files and loose for per-bit files.

Stations

Currently supported stations are dcf77 and msf. DCF77 is the German time station at 77.5 kHz, and MSF is the British time station at 60 kHz. Some information these stations can be found at:

• https://en.wikipedia.org/wiki/DCF77
• https://www.ptb.de/cms/en/ptb/fachabteilungen/abt4/fb-44/ag-442/dissemination-of-legal-time/dcf77.html
• https://en.wikipedia.org/wiki/Time_from_NPL_(MSF)
• https://www.npl.co.uk/products-services/time-frequency/msf-radio-time-signal

Input files

All input files in plain text.

Per-bit files

These files generally contain one line per minute, unless reception errors occur in which case false minute markers might be received. The analyzer returns the date, time, day-of-week, and DST (daylight saving time) status of each analyzed minute. Parity and temporal errors are also reported. Some information is only available for certain transmitters:

• DCF77:

  • call bit for technicians (does not affect the received data)
  • announcement of leap second
  • information meant for third parties

• MSF:

  • DUT1 value (difference between UT1 and UTC in tenths of seconds)

File format for DCF77

There are five characters for DCF77 log files. All other characters are discarded.

• '0' denotes a 0 bit
• '1' denotes a 1 bit
• '_' denotes a bit which could not be properly decoded
• '*' resets the internal decoder state, it should generally not be followed by a newline
• newline denotes a new minute

File format for MSF

There are seven characters for MSF log files. All other characters are discarded.

• '0' denotes a 0,0 bit pair
• '1' denotes a 1,0 bit pair
• '2' denotes a 0,1 bit pair (only occurs in bit 1-16)
• '3' denotes a 1,1 bit pair (only occurs in bit 53-58)
• '4' denotes the 500 ms new-minute marker
• '_' denotes a bit which could not be properly decoded
• '*' resets the internal decoder state
• (the newline is just a comment here)

Per-edge files

For each received station, these files contain one edge transition (low-to-high or high-to-low) per line. A second normally contains an even number of edge transitions (2 for a regular second, 0 for the missing bit at the end-of-minute for DCF77, and 4 for a (0,1) bit pair for MSF).

The format of each line is " ":

• station: one character to denote the station, 'D' for DCF77 and 'M' for MSF
• edge: whether the new state of the edge is high
• time: uptime of the receiver in microseconds, clipped to 32 bits (wraps each 71m35s)
• tick: sub-division of the current second used to orchestrate events in rp-rs-radio-clock

Comments are also supported, these are always full-line, such lines start with a '#'