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.
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.
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
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.
