CODEWITHSUNDEEP
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Rajesh Rajput
Rajesh Rajput

Reputation: 263

Calculate Latitude and longitude more between Latitude/Longitude points?

Latitude: 22.744812, Longitude: 75.892578

The above would be considered my center point.

And now I need to determine the latitude and longitude points from center point 1000 meter outward to each NSWE corners. So I would have a central long/lat, N, S, E and W long/lat..

So I would end up with 4 additional lat/long pairs.

What I am trying to resolve is a formula, preferably that can be done on a standard calculator to determine these 4 NSWE points based on the central point.

Upvotes: 0

Views: 819

Answers (3)

Javier Chávarri
Javier Chávarri

Reputation: 1615

You could use MapKit for that:

- (CLLocationCoordinate2D *) calculateSquareCoordinates:(CLLocation*)center withRadius:(float)radius{

    MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(center.coordinate, radius*2, radius*2);

    CLLocationCoordinate2D  points[4];

    points[0] = CLLocationCoordinate2DMake(region.center.latitude - region.span.latitudeDelta/2, region.center.longitude - region.span.longitudeDelta/2);
    points[1] = CLLocationCoordinate2DMake(region.center.latitude + region.span.latitudeDelta/2, region.center.longitude - region.span.longitudeDelta/2);
    points[2] = CLLocationCoordinate2DMake(region.center.latitude + region.span.latitudeDelta/2, region.center.longitude + region.span.longitudeDelta/2);
    points[3] = CLLocationCoordinate2DMake(region.center.latitude - region.span.latitudeDelta/2, region.center.longitude +  region.span.longitudeDelta/2);

    return points;
}

and just call 

CLLocationCoordinate2D *fourPoints = [self calculateSquareCoordinates:center withRadius:1000];

on your code.

Upvotes: 3

Stochastically
Stochastically

Reputation: 7836

The average radius of the earth is around 6371000 metres. This means that

1 degree of lattitude is equivalent to 6371000 * PI / 180 metres

(NB: PI = 3.14159... etc). However, 1 degree of longitude depends on the lattitude that you are. At the equator, one degree of longitude corresponds to the same distance in metres as 1 degree of lattitude. However, at the north and south poles, all longitude values are the same point (i.e. the pole itself), so 1 degree of longitude at the poles is zero metres. The formula for longitude is

1 degree of longitude is equivalent to 637100 * PI / 180 * COS(Lattitude)

where COS is the trigonometric cosine function. If you make these conversions, then you can do the calculation on a standard calculator. However, be aware that these are approximations that work well over short distances (e.g. less than a few hundred kilometers), but over long distances (e.g. thousands of kilometers) they become more and more inaccurate.

Upvotes: 0

Bonnie
Bonnie

Reputation: 4953

you will have to use the Haversine formula to calculate the Lat/Long based on distance from a starting Lat/Long. have a look at this Link

Upvotes: 0

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