sl2json

Convert Lowrence SL2 files to streaming/newline-delimited JSON (ndjson)

• http://www.lowrance.com/
• https://wiki.openstreetmap.org/wiki/SL2
• https://github.com/kmpm/node-sl2format (very helpful additional field breakdown)
• https://stackoverflow.com/q/52280751/1457051
• https://gitlab.com/hrbrmstr/arabia (R package)

Install (macOS homebrew)

brew install hrbrmstr/tap/sl2json

Build

Just run make. There are no external dependencies outside the need for a C++ compiler. Compilation has been tested with both gcc and clang toolchains.

Run

$ ./sl2json some_sl2_file.sl2 > streaming_json_version_of_the_data.json

Sample record

{
  "channel": 2,
  "upperLimit": 0,
  "lowerLimit": 13.4,
  "waterDepth": 2.838,
  "keelDepth": 0.328084,
  "speedGps": 0,
  "temperature": 15.6947,
  "longitude": 4433309,
  "latitude": 7003054,
  "speedWater": 0,
  "track": 3.50811,
  "altitude": 333.202,
  "heading": 0,
  "headingValid": false,
  "altitudeValid": false,
  "gpsSpeedValid": false,
  "waterTempValid": false,
  "positionValid": false,
  "waterSpeedValid": false,
  "trackValid": false,
  "timeOffset": 1404539
}