[Phphtmllib-devel] SF.net SVN: phphtmllib:[3513] trunk/open2300/lib/modules/api/ AviationWeather.inc

[<he...@us...>]

Revision: 3513
          http://phphtmllib.svn.sourceforge.net/phphtmllib/?rev=3513&view=rev
Author:   hemna
Date:     2010-06-18 03:45:21 +0000 (Fri, 18 Jun 2010)

Log Message:
-----------
pressure altitude

Modified Paths:
--------------
    trunk/open2300/lib/modules/api/AviationWeather.inc

Modified: trunk/open2300/lib/modules/api/AviationWeather.inc
===================================================================
--- trunk/open2300/lib/modules/api/AviationWeather.inc	2010-06-18 02:10:33 UTC (rev 3512)
+++ trunk/open2300/lib/modules/api/AviationWeather.inc	2010-06-18 03:45:21 UTC (rev 3513)
@@ -66,6 +66,7 @@
 		if ($metar != null && strlen($metar) > 0) {
 			$this->process_metar($metar, $wxInfo);
 			$wxInfo["metar"] = $metar;
+
 			
 			$airport = $this->cache->get($icao);
 			if ($airport != null) {
@@ -81,6 +82,9 @@
 						$this->cache->set($icao,$airport);
 					}
 				}
+
+				//now do Pressure Altitude and Density Altitude
+			   $wxInfo["PressureAltitude"] = $this->pressure_altitude($wxInfo["BaroHPA"], $wxInfo["altitude"]);
 			}
 			//$this->metars[] = $wxInfo;
 			//need to combine this info w/ the airport data cache.
@@ -619,6 +623,31 @@
  		$offset = $origin_dtz->getOffset($origin_dt) - $remote_dtz->getOffset($remote_dt);
  		return $offset/3600;
  	}
+
+
+	protected function pressure_altitude($pressure, $altitude) {
+	    // Pressure Altitude
+		 // Palt = ( 1 - (P / 1013.25) ^ .190284) * 145366.45
+
+	    $Pst = 1013.25;
+		 $Pexp = .190284;
+		 $fn = 145366.45;
+
+		 $tmp1 = $pressure/$Pst;
+		 $tmp2 = pow($tmp1, $Pexp);
+
+		 $Pa = $fn * (1 - pow(($pressure/$Pst) , $Pexp));
+
+		 return round($Pa + $altitude,1);
+	}
+
+
+	protected function density_altitude() {
+
+	}
+
+
+
  	
 	
 					


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