PHP: Add miles to lat/lng pair to get new pair

Question

What is the easiest way to add a distance (100 miles) to a latitude/logitude pair, and a direction (north, etc) to get a new lat/lng pair?

Edited to add: I've been looking at the example on this page but cant seem to get it to work using PHP: http://www.movable-type.co.uk/scripts/latlong.html

I'm voting to close this question as off-topic because this has nothing to do with programming whatsoever. — Daan
What do you mean it has nothing to do with programming? I am trying to automate some location targeting using PHP — Jay
No you'll have to do a calculation. So I'd suggest you'll ask it on mathematica.stackexchange.com. No programming at all involved here. — Daan
From the page you've linked, Destination point given distance and bearing from start point and remember that you need to convert lat/lng and bearing to radians before executing the equation, and to convert lat/long back to degrees afterwards.... show your actual code — Mark Baker
Thanks mark, I was actually forgetting to convert to radians — Jay

Jay Jay · Accepted Answer · 2016-01-07T16:02:16

Here is my working code, takes a $lat/$lng and adds 75 miles EAST in this example.

        $distance = 75;
        $bearing = deg2rad(90);
        $lat1 = deg2rad($lat);
        $lng1 = deg2rad($lng);
        echo $lat1 . ', ' . $lng1;
        echo '<br>';
        $lat2 = asin(sin($lat1)*cos($distance/ 3959) + cos($lat1)*sin($distance/ 3959)*cos($bearing));
        $lng2 = $lng1 + atan2(sin($bearing)*sin($distance/3959)*cos($lat1), cos($distance/3959)-sin($lat1)*sin($lat2));
        echo rad2deg($lat2) . ', ' . rad2deg($lng2);

PHP: Add miles to lat/lng pair to get new pair

1 Answers