'53.344104','lng'=>'-6.2674937');
$coords[]=array('lat' => '51.5081289','lng'=>'-0.128005');
*/
function get_midpoint($coords) {
$count_coords = count($coords);
$xcos = 0.0;
$ycos = 0.0;
$zsin = 0.0;
foreach ($coords as $lnglat) {
$lat = $lnglat['lat'] * pi() / 180;
$lon = $lnglat['lng'] * pi() / 180;
$acos = cos($lat) * cos($lon);
$bcos = cos($lat) * sin($lon);
$csin = sin($lat);
$xcos += $acos;
$ycos += $bcos;
$zsin += $csin;
}
$xcos /= $count_coords;
$ycos /= $count_coords;
$zsin /= $count_coords;
$lon = atan2($ycos, $xcos);
$sqrt = sqrt($xcos * $xcos + $ycos * $ycos);
$lat = atan2($zsin, $sqrt);
return array($lat * 180 / pi(), $lon * 180 / pi());
}
function echoQrbCalcLink($mygrid, $grid, $vucc, $isVisitor = false) {
$echo = "";
if (!empty($grid)) {
$echo = $grid;
if (!empty($mygrid)) {
$echo .= (!$isVisitor) ? (' ') : '';
}
} else if (!empty($vucc)) {
$echo = $vucc;
if (!empty($mygrid)) {
$echo .= (!$isVisitor) ? (' ') : '';
}
}
return $echo;
}
/**
* Function to calculate the maximum distance in a bunch of QSOs
*
* @param string $mylocator Maidenhead locator of the station
* @param object $qsos Object of QSOs
* @param string $unit Unit of measurement
*
* @return object $maxdistanceqso Object of the QSO with the maximum distance
* @return float $maxdistance Maximum distance
*/
function getMaxDistanceQSO($mylocator, $qsos, $unit = "M") {
//return nothing for empty QSO set
if (count($qsos) < 1) {
return null;
}
//collect maximum data
$maxdistance = 0;
$maxdistanceqso = null;
//iterate through all qsos
foreach ($qsos as $row) {
if (empty($row['gridsquare_recv'])) {
continue;
}
//get distance in kilometers
$distance = $this->distance($mylocator, $row['gridsquare_recv'], $unit);
//store new highscore if present
if ($distance > $maxdistance) {
$maxdistance = $distance;
$maxdistanceqso = $row;
}
}
$result = [];
$result['qso'] = $maxdistanceqso;
$result['distance'] = $maxdistance;
//return findings
return $result;
}
/**
* Function to calculate the center of a bunch of coordinates
* Source: https://www.phpsnippet.com/snippet/center-point-of-multiple-gps-coordinates-with-php
*
* @param array $coordinates Array of coordinates [latitude, longitude]
* Example:
* $coordinates = [
* [37.7797, -122.41924],
* [37.77323, -122.41114],
* [37.79203, -122.40864],
* [37.7952, -122.4222]
* ];
*
* @return array [latitude, longitude] Center of the coordinates
*/
function getCenterLatLng($coordinates) {
$x = $y = $z = 0;
$n = count($coordinates);
foreach ($coordinates as $point)
{
$lt = $point[0] * pi() / 180;
$lg = $point[1] * pi() / 180;
$x += cos($lt) * cos($lg);
$y += cos($lt) * sin($lg);
$z += sin($lt);
}
$x /= $n;
$y /= $n;
return [atan2(($z / $n), sqrt($x * $x + $y * $y)) * 180 / pi(), atan2($y, $x) * 180 / pi()];
}
function validate_grid($grid, $type='any') {
// (Try to) Detect placeholders like AA00aa (returned from qrz.com for example)
if (strlen($grid) == 6 && strtoupper($grid) == 'AA00AA') {
return false;
}
if ($type == 'vucc') goto vucc;
// Allow 6-digit locator
if (preg_match('/^[A-Ra-r]{2}[0-9]{2}[A-Za-z]{2}$/', $grid)) return true;
// Allow 4-digit locator
if (preg_match('/^[A-Ra-r]{2}[0-9]{2}$/', $grid)) return true;
// Allow 2-digit locator
if (preg_match('/^[A-Ra-r]{2}$/', $grid)) return true;
// Allow 8-digit locator
if (preg_match('/^[A-Ra-r]{2}[0-9]{2}[A-Za-z]{2}[0-9]{2}$/', $grid)) return true;
// Allow 10-digit locator
if (preg_match('/^[A-Ra-r]{2}[0-9]{2}[A-Za-z]{2}[0-9]{2}[A-Za-z]{2}$/', $grid)) return true;
if ($type == 'grid') return false;
vucc:
// Allow 4-digit grid line
if (preg_match('/^[A-Ra-r]{2}[0-9]{2},[A-Ra-r]{2}[0-9]{2}$/', $grid)) return true;
// Allow 6-digit grid line
if (preg_match('/^[A-Ra-r]{2}[0-9]{2}[A-Za-z]{2},[A-Ra-r]{2}[0-9]{2}[A-Za-z]{2}$/', $grid)) return true;
// Allow 4-digit grid corner
if (preg_match('/^[A-Ra-r]{2}[0-9]{2},[A-Ra-r]{2}[0-9]{2},[A-Ra-r]{2}[0-9]{2},[A-Ra-r]{2}[0-9]{2}$/', $grid)) return true;
// Allow 6-digit grid corner
if (preg_match('/^[A-Ra-r]{2}[0-9]{2}[A-Za-z]{2},[A-Ra-r]{2}[0-9]{2}[A-Za-z]{2},[A-Ra-r]{2}[0-9]{2}[A-Za-z]{2},[A-Ra-r]{2}[0-9]{2}[A-Za-z]{2}$/', $grid)) return true;
return false;
}
}
function calc_distance($lat1, $lon1, $lat2, $lon2, $unit = 'M', $ant_path = null) {
$theta = $lon1 - $lon2;
$dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2)) + cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta));
$dist = acos($dist);
$dist = rad2deg($dist);
$dist = $dist * 60 * 1.1515;
if ($ant_path == "L") { // we only need to calculate the distance for long paths, all other paths are the same
$dist = 24880 - $dist;
}
if ($unit == "K") {
$dist *= 1.609344;
} else if ($unit == "N") {
$dist *= 0.8684;
}
if ((is_nan($dist)) || !(is_numeric($dist))) { // Special-Case, catch same grid and/or Errors
$dist = 0;
}
return round($dist, 1);
}
function bearing($lat1, $lon1, $lat2, $lon2, $unit = 'M', $ant_path = null) {
$dist = calc_distance($lat1, $lon1, $lat2, $lon2, $unit, $ant_path);
$dist = round($dist, 0);
$bearing = get_bearing($lat1, $lon1, $lat2, $lon2);
if ($ant_path == 'L') {
$bearing = ($bearing + 180) % 360;
}
$dirs = array("N", "E", "S", "W");
$rounded = round($bearing / 22.5) % 16;
if (($rounded % 4) == 0) {
$dir = $dirs[$rounded / 4];
} else {
$dir = $dirs[2 * floor(((floor($rounded / 4) + 1) % 4) / 2)];
$dir .= $dirs[1 + 2 * floor($rounded / 8)];
#if ($rounded % 2 == 1)
# $dir = $dirs[round_to_int($rounded/4) % 4] . "-" . $dir;
}
$var_dist = "";
#return $dir;
if (isset($dist)) {
$var_dist = $dist;
switch ($unit) {
case 'M':
$var_dist .= " miles";
break;
case 'N':
$var_dist .= " nautic miles";
break;
case 'K':
$var_dist .= " kilometers";
break;
}
}
return round($bearing, 0) . "º " . $dir . " " . $var_dist;
}
function get_bearing($lat1, $lon1, $lat2, $lon2, $ant_path = null) {
$bearing = (int)(rad2deg(atan2(sin(deg2rad($lon2) - deg2rad($lon1)) * cos(deg2rad($lat2)), cos(deg2rad($lat1)) * sin(deg2rad($lat2)) - sin(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($lon2) - deg2rad($lon1)))) + 360) % 360;
if ($ant_path == 'L') { // Long path is the reciprocal of the short-path bearing
$bearing = ($bearing + 180) % 360;
}
return $bearing;
}
function qra2latlong($strQRA) {
$strQRA = preg_replace('/\s+/', '', ($strQRA ?? ''));
if (substr_count($strQRA, ',') > 0) {
$grids = explode(',', $strQRA);
if (count($grids) != 2 && count($grids) != 4) {
return false;
}
$lengths = array_map('strlen', $grids);
if (count(array_unique($lengths)) != 1) {
return false;
}
$lat = 0; $lng = 0;
foreach ($grids as $g) {
$c = qra2latlong($g);
if (!$c) { return false; }
$lat += $c[0]; $lng += $c[1];
}
$n = count($grids);
return array($lat / $n, $lng / $n);
}
if ((strlen($strQRA) % 2 == 0) && (strlen($strQRA) <= 10)) { // Check if QRA is EVEN (the % 2 does that) and smaller/equal 8
$strQRA = strtoupper($strQRA);
if (strlen($strQRA) == 2) $strQRA .= "55AA00AA";
elseif (strlen($strQRA) == 4) $strQRA .= "MM00AA";
elseif (strlen($strQRA) == 6) $strQRA .= "55AA";
elseif (strlen($strQRA) == 8) $strQRA .= "MM";
if (!preg_match('/^[A-R]{2}[0-9]{2}[A-X]{2}[0-9]{2}[A-X]{2}$/', $strQRA)) {
return false;
}
list($a, $b, $c, $d, $e, $f, $g, $h, $i, $j) = str_split($strQRA, 1); // Maidenhead is always alternating. e.g. "AA00AA00AA00" - doesn't matter how deep. 2 chars, 2 numbers, etc.
$a = ord($a) - ord('A');
$b = ord($b) - ord('A');
$c = ord($c) - ord('0');
$d = ord($d) - ord('0');
$e = ord($e) - ord('A');
$f = ord($f) - ord('A');
$g = ord($g) - ord('0');
$h = ord($h) - ord('0');
$i = ord($i) - ord('A');
$j = ord($j) - ord('A');
$nLong = ($a * 20) + ($c * 2) + ($e / 12) + ($g / 120) + ($i / 2880) - 180;
$nLat = ($b * 10) + $d + ($f / 24) + ($h / 240) + ($j / 5760) - 90;
$arLatLong = array($nLat, $nLong);
return $arLatLong;
} else {
return array(0, 0);
}
}
/* End of file Qra.php */