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copied!<p>First, calculate the distance you will travel based on your current speed and your known time interval ("next time"): </p> <pre><code>distance = speed * time </code></pre> <p>Then you can use this formula to calculate your new position (lat2/lon2):</p> <pre><code>lat2 =asin(sin(lat1)*cos(d)+cos(lat1)*sin(d)*cos(tc)) dlon=atan2(sin(tc)*sin(d)*cos(lat1),cos(d)-sin(lat1)*sin(lat2)) lon2=mod( lon1-dlon +pi,2*pi )-pi </code></pre> <p>For an implementation in Javascript, see the function <code>LatLon.prototype.destinationPoint</code> on <a href="http://www.movable-type.co.uk/scripts/latlong.html" rel="nofollow noreferrer">this page</a></p> <p><strong>Update</strong> for those wishing a more fleshed-out implementation of the above, here it is in Javascript:</p> <pre><code> /** * Returns the destination point from a given point, having travelled the given distance * on the given initial bearing. * * @param {number} lat - initial latitude in decimal degrees (eg. 50.123) * @param {number} lon - initial longitude in decimal degrees (e.g. -4.321) * @param {number} distance - Distance travelled (metres). * @param {number} bearing - Initial bearing (in degrees from north). * @returns {array} destination point as [latitude,longitude] (e.g. [50.123, -4.321]) * * @example * var p = destinationPoint(51.4778, -0.0015, 7794, 300.7); // 51.5135°N, 000.0983°W */ function destinationPoint(lat, lon, distance, bearing) { var radius = 6371e3; // (Mean) radius of earth var toRadians = function(v) { return v * Math.PI / 180; }; var toDegrees = function(v) { return v * 180 / Math.PI; }; // sinφ2 = sinφ1·cosδ + cosφ1·sinδ·cosθ // tanΔλ = sinθ·sinδ·cosφ1 / cosδ−sinφ1·sinφ2 // see mathforum.org/library/drmath/view/52049.html for derivation var δ = Number(distance) / radius; // angular distance in radians var θ = toRadians(Number(bearing)); var φ1 = toRadians(Number(lat)); var λ1 = toRadians(Number(lon)); var sinφ1 = Math.sin(φ1), cosφ1 = Math.cos(φ1); var sinδ = Math.sin(δ), cosδ = Math.cos(δ); var sinθ = Math.sin(θ), cosθ = Math.cos(θ); var sinφ2 = sinφ1*cosδ + cosφ1*sinδ*cosθ; var φ2 = Math.asin(sinφ2); var y = sinθ * sinδ * cosφ1; var x = cosδ - sinφ1 * sinφ2; var λ2 = λ1 + Math.atan2(y, x); return [toDegrees(φ2), (toDegrees(λ2)+540)%360-180]; // normalise to −180..+180° } </code></pre>

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