⏱️ TLDR

• Traditional: (latitude [0 to 90 °N | 0 to 90 °S], longitude [0 to 180 °E | 0 to 180 °W]) ≈ (Y, X)

  Latitude - north/south position - is easier to measure, from the position of the sun / stars. For measuring longitude - east/west position - you need to know the time.

• GeoJSON: [longitude [-180 to 180 °], latitude [-90 to 90 °]] ≈ (X, Y)

  [longitude, latitude]

🤔 Why is the order of latitude and longitude not always the same?

The difference between traditional (latitude, longitude) and GeoJSON’s [longitude, latitude] comes from different standards for representing geographic data. Here’s why this difference exists and how you can remember or recognize the order:

Why the Difference?

1. Traditional Coordinate System (latitude, longitude):
   • Historically, geographic coordinates are presented as latitude, longitude because latitude (north/south position) was measured first by ancient civilizations and is easier to conceptualize based on Earth's natural gridlines (Equator).
2. GeoJSON (longitude, latitude):
   • GeoJSON follows the convention used in many computer graphics systems, particularly mapping software based on Cartesian coordinates (X, Y).
   • In GeoJSON, the Xaxis (which represents longitude) is listed first, followed by the Yaxis (latitude), as per Cartesian coordinates.

How to Remember / Recognize the Order

Here are some tips to help you remember the correct order depending on the context:

1. Traditional Context (latitude, longitude):
   • If you're reading or using coordinates in a traditional geographic sense (maps, GPS devices, etc.), the order is typically latitude, longitude.
   • Mnemonic: "Latitude comes first, just like climbing up or down (north/south) a ladder."
2. GeoJSON and Data Context [longitude, latitude]:
   • In GeoJSON, the order is longitude, latitude because it’s like X, Y coordinates in Cartesian geometry. It reflects east-west first, then north-south.
   • Mnemonic: "Longitude comes first in Long forms like JSON."
3. Recognizing the Order:
   • Latitudes will always range from 0 or -90 to 90 (because they represent degrees north or south of the Equator).
   • Longitudes will range from 0 or -180 to 180 (because they represent degrees east or west of the Prime Meridian).
   • If you see values where the first number is smaller than -90 or larger than 90, it’s likely longitude, latitude (e.g., GeoJSON). If not it could be either 😅

Longitude (East-West, x) & Latitude (East-West, x)

Longitude “x”

Longitude measures the distance east or west from the Greenwich prime meridian. Meridians of longitude have are lines that run North to South and have a constant longitude.

Latitude “y”

Latitude measures the distance north or south from the equator.

Parallels of latitude are lines that run parallelly to the equator and have a constant latitude

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Latitude is Lateral ⇒ Lateral parallels of latitude

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