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| 12:14 | Sunday 05 February 2012 | |||||||||
 
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Distance
Calculation of the distance (km, meters, mile, foot) between two point in the earth, is possible calcolate the bearing angle between the points and the destination point with start point, distance and bearing.
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Calculating the distance between two geographical points
Calculation of direction between two geographical points
Calculation of the destination point
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Format
Value range
Valid value for the latitude are from -90.0° to 90.0° for the longitude are from -180.0° to 180.0°, the + sign should be omitted, while the minus sign is not necessary if there is a radio component to select the direction N-S or W-E (Degree and Decimal format).Decimal
You have to select a direction (N-S or W-E) and insert a number from 0 to 90 for the latitude or from 0 to 180 for the longitude (example 45.12345).Degree
Degree format is composed of direction (N-S or W-E) and three sets of numbers separate by the symbols for degrees (°), minutes (’), and seconds (").Degree is an integer value without sign, from 0 to 90 for the latitude or from 0 to 180 for the longitude. Minute is an integer value without sign, from 0 to 59. Seconds is a double value without sign, from 0 (or 0.0000) to 59.9999.
Coordinates
Coordinates format is the pair of latitude and longitude, with sign minus (-) for the direction south latitude and west longitude separate by comma symbol (,), here some example:52.5163 , 13.3779
40.7682 , -73.9816
-22.9708 , -43.1830
Search on map
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to open the webpage Earth Coordinate, here you obtain the latitude and longitude simply by clicking on the map, and save the value by the button save. Back to top
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Calculating the distance between two geographical points
The formula used to determine the shortest distance between two points on the land (geodesic), approximates the geoid to a sphere of radius R = 6372.795477598 km (radius quadric medium), so the calculation could have a distance error of 0.3%, particularly in the polar extremes, and for long distances through various parallel. Given two points A and B on the sphere expressed by latitude (lat) and longitude (lon) you will have:distance (A, B) = R * arccos (sin(latA) * sin(latB) + cos(latA) * cos(latB) * cos(lonA-lonB))
The angles used are expressed in radians, converting between degrees and radians is obtained by multiplying the angle by pi and dividing by 180.
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Calculation of direction between two geographical points
To determine the direction from the starting point between two points on the earth, use the following formula:Δφ = ln( tan( latB / 2 + π / 4 ) / tan( latA / 2 + π / 4) )
Δlon = abs( lonA - lonB )
bearing : θ = atan2( Δlon , Δφ )
Note: 1) ln = natural log 2) if Δlon > 180° then Δlon = Δlon (mod 180).
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Calculation of the destination point
To determine the destination point, knowing the starting point the direction θ and the distance d, we use the following formula:latB = asin( sin( latA) * cos( d / R ) + cos( latA ) * sin( d / R ) * cos( θ ))
lonB = lonA + atan2(sin( θ ) * sin( d / R ) * cos( latA ), cos( d / R ) − sin( latA ) * sin( latB ))
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If detected inaccuracies bug, want to suggest new features or simply express your opinion of the site web add a comment.Thanks in advance for your contribution to improve this site.
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