Spatial Accuracy

Spatial Accuracy in DMS (Degrees Minutes Seconds)

• The Earth is about 40,000 km around
• 40,000 / 360 degrees ~ 111 km/degree
• 111 km/degree / 60 minutes/degree ~ 1.85 km/minute
• 1.85 km/degree / 60 seconds/minute ~ 0.03 km/second (30 meters/second)
• To maintain 1 meter accuracy, we need to keep two digits after the seconds decimal!

Spatial Accuracy in DD (Decimal Degrees)

• The Earth is about 40,000 km around
• 40,000 / 360 degrees ~ 111 km/degree or 111,000 m/degree
• To maintain 1 meter accuracy, we need to keep 5 digits after the decimal!

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