Calculate border crosses with Google Maps Timeline data

extract.js

/*
  I need to monitor my UK border crosses for residential purposes.
  This script will calculate whenever I moved more than 5 degrees, either on lat or long, from one datapoint to the other, since the start of 2017.
*/

// First of all, go to Google Takeout and fetch your Location data.

// Then, for each day, extract the last position for the day with the following command (using gojq)
// cat Records.json | gojq -r '[.locations[] | select((.timestamp | sub("\\.[0-9]+";"") | strptime("%Y-%m-%dT%H:%M:%SZ")) | mktime >= 1483228800) | {latitudeE7, longitudeE7, accuracy, source, timestamp}] | group_by(.timestamp[:10]) | map(max_by(.timestamp)) | map({latitude: (.latitudeE7 / 10000000), longitude: (.longitudeE7 / 10000000), accuracy: .accuracy, source: .source, timestamp: .timestamp})'  > grouped.json
// *** You might want to change the Unix timestamp after mktime to filter on your needs

// Now run this script
// node extracted.js > data.json

const d = require('./grouped.json')

// Format is:
// [{
//     accuracy: 21,
//     latitude: 51.5197102,
//     longitude: -0.0691128,
//     source: 'WIFI',
//     timestamp: '2017-04-10T23:59:14.996Z'
//   }]

const r = d.reduce((acc, el ) => {
    const last = acc[acc.length -1]
    const lat = Math.abs(el.latitude - last.latitude) > 5 // You might want to filter on less or more distance
    const long = Math.abs(el.longitude - last.longitude) > 5 // You might want to filter on less or more distance
    if (lat || long) acc.push(el)
    return acc
}, [d[0]])

console.log(JSON.stringify(r))

// Finally, make a CSV out of it
// cat data.json | gojq -r '["accuracy","latitude","longitude","source","timestamp"], (.[] | [.accuracy,.latitude,.longitude,.source,.timestamp]) | @csv' > data.csv