Author Topic: Degrees of Separation  (Read 97 times)

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Offline AG-51_Mac

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Degrees of Separation
« on: February 12, 2022, 08:58:16 AM »
For those of you who have a problem with the Hornet (or other aircraft) navigation units, here is a breakdown of it all:

There are Latitudes going from 90° North to 0° at the equator down to 90° South (often written as -90°). I focus on Latitudes in a moment.
There are Longitudes going from 0° at London, England (Greenwich) going westward to 180° in the Pacific by negative numbers then back down further westward (often written as positive numbers for EAST), until you get back to London again.

Longitude distances PER DEGREE change based on the Latitude. So let's skip that.

Latitude distances PER DEGREE do NOT change. One-degree latitude DISTANCE at the equator is the same as one-degree DISTANCE (almost) at the North Pole. One degree of Latitude is exactly 60 nautical miles.

Degrees Latitude can be subdivided into minutes and seconds (of Latitude DISTANCE). The degree is denoted by the ° symbol. Forty-five degrees would be listed as 45°. You can, (but it's very rare), say 45 1/2°. Usually, you use MINUTES to get partial degrees. One minute of Latitude is exactly one nautical mile.

Minutes of Latitude is denoted by the single quote ' symbol. There are 60 minutes (of Latitude) PER DEGREE. So half a degree would be 30 minutes (of Latitude) or 30' N (or S). The Latitude, in this precision, is listed as 45° 30' N (or S). Note the space (normally) between the degree symbol and the minute value.

Seconds of Latitude is denoted by the double quote " symbol. There are 60 seconds (of Latitude) PER MINUTE. So half a minute would be 30 seconds (of Latitude) or 30" N (or S). The Latitude, in this precision, is listed as 45° 30' 30" N (or S). Note the spaces (normally) between the degree symbol, the minute symbol, and the seconds value. One second of Latitude is almost 31 meters (30.8667 m).

In DCS, the F/A-18 Hornet (in precision mode) can enter one-hundredth of a second of a minute of a degree (Latitude or Longitude). The Latitude DISTANCE of 1/100th of a second is just over 3 cm (Just over an inch)!

An example would be the Statue of Liberty in New York City's harbor. It is listed as 40° 41' 20.70" N, 74° 02' 39.83" W. (I'm not sure which part of the main entrance door's doorknob that is.)
40° 41.345' N, 74° 02.664' W.
(without the North N or South S) 40.689082° -74.044398°.
(in MGRS) 18 T WL 80745 04682.

I hope this helps you understand the geo-spherical coordinate system.
« Last Edit: February 12, 2022, 09:11:45 AM by AG-51_Mac »
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