[Phphtmllib-devel] SF.net SVN: phphtmllib:[3521] trunk/open2300/lib/modules/api/ AviationWeather.inc

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

Revision: 3521
          http://phphtmllib.svn.sourceforge.net/phphtmllib/?rev=3521&view=rev
Author:   hemna
Date:     2010-06-28 23:20:40 +0000 (Mon, 28 Jun 2010)

Log Message:
-----------
hacks

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

Modified: trunk/open2300/lib/modules/api/AviationWeather.inc
===================================================================
--- trunk/open2300/lib/modules/api/AviationWeather.inc	2010-06-28 22:40:43 UTC (rev 3520)
+++ trunk/open2300/lib/modules/api/AviationWeather.inc	2010-06-28 23:20:40 UTC (rev 3521)
@@ -717,10 +717,10 @@
 	 * @link http://www.4wx.com/wxcalc/formulas/densityAltitude.php
 	 */
 	protected function density_altitude($altitude, $Pmb, $PinHg, $tempC, $dewC) {
+		$this->e_calc($altitude, $Pmb, $PinHg, $tempC, $dewC);
 		
 		//get vapor pressure ($Vp)
-		$Vpexp = (7.5*$dewC) / (237.7+$dewC);
-		$Vp = 6.11*pow(10, $Vpexp);	
+		$Vp = $this->vapor_pressure($dewC);	
 
 		//get virtual Temp $Tv (in Kelvin)
 		$TvK = ($tempC / (1-($Vp / $Pmb) * (1-0.622)));
@@ -733,9 +733,164 @@
 		
 		return $Ad;
 	}
+	
+	
+   private function vapr_pressure($dewC) {
+   		$Vpexp = (7.5*$dewC) / (237.7+$dewC);
+		$Vp = 6.11*pow(10, $Vpexp);	
+		return $Vp;
+   }
 
+   // Calculate absolute air pressure given the barometric pressure(mb) and altitude(meters)
+	private function calcAbsPress($Pmb, $altM) {
+		$k1 = 0.190284;
+		$k2 = 8.4288*Math.pow(10,-5);
+		$p1 = pow($Pmb,$k1);
+		$p2 = $altM*$k2;
+		$p3 = 0.3+pow( ($p1-$p2), (1/$k1) );
+		return $p3;
+	}
+ 
+ 
+	//  Calculate the air density in kg/m3
+	private function calcDensity($absPmb, $e, $tc) {
+		$Rv=461.4964;
+		$Rd=287.0531;
+	
+		$tk = $tc + 273.15;
+		$pv = $e*100;
+		$pd = ($absPmb-$e)*100;
+		$d= ($pv/($Rv*$tk)) + ($pd/($Rd*$tk));
+		return $d;
+	}
+	
+	// Calculate the ISA altitude (meters) for a given density (kg/m3)
+	private function calcAltitude($d) {
+		$g=9.80665;
+		$Po=101325;
+		$To=288.15;
+		$L=6.5;
+		$R=8.314320;
+		$M=28.9644;
 
+		$D=$d*1000;
 
+		$p2=( ($L*$R)/($g*$M-$L*$R) )*log( ($R*$To*$D)/($M*$Po) );
+
+		$H=-($To/$L)*( exp($p2)-1 );
+
+		$h = $H*1000;
+
+		return $h;
+	}
+
+
+
+	// Calculate the Z altitude (meters), given the H altitide (meters)
+	private function calcZ($h) {
+		$r=6369E3;
+
+		return (($r*$h)/($r-$h));
+
+	}
+
+
+	// Calculate the H altitude (meters), given the Z altitide (meters)
+	private function calcH($z) {
+		$r=6369E3;
+
+		return (($r*$z)/($r+$z));
+	}
+
+	
+	// Calculate the actual pressure (mb)from the altimeter setting (mb) and geopotential altitude (m)
+	private function calcAs2Press($As, $h) {
+		$k1=.190263;
+		$k2=8.417286E-5;
+
+		$p=pow( (pow($As,$k1)-($k2*$h)),(1/$k1) );
+
+		return $p;
+	}
+	
+	
+	private function e_calc($altitude, $Pmb, $PinHg, $tempC, $dewC) {
+
+		$in_per_mb = (1/33.86389);		
+		$mb_per_in = 33.86389;
+				
+		$m_per_ft = 0.304800;
+		$ft_per_m = (1/.304800);
+		
+
+		$zm = $altitude*$m_per_ft;
+
+
+		// Calculate the vapor pressures (mb) given the ambient temperature (c) and dewpoint (c)
+
+		$esmb = $this->calcVaporPressure_wobus($tempC);
+		$emb = $this->calcVaporPressure_wobus($dewC);
+
+
+		// Calculate geopotential altitude H (m) from geometric altitude (m) Z
+
+		$hm = $this->calcH($zm);
+
+
+		// Calculate the absolute pressure given the altimeter setting(mb) and geopotential elevation(meters)
+
+		$actpressmb = $this->calcAs2Press($Pmb, $hm);
+
+
+		// Calculate the air density (kg/m3) from absolute pressure (mb) vapor pressure (mb) and temp (c)
+
+		$density = $this->calcDensity($actpressmb, $emb, $tempC);
+		$relden = 100*($density/1.225);
+
+
+		// Calculate the geopotential altitude (m) in ISA with that same density (kg/m3)
+
+		$densaltm = $this->calcAltitude($density);
+
+		// Calculate geometric altitude Z (m) from geopotential altitude (m) H
+
+		$densaltzm = $this->calcZ($densaltm);
+
+
+		// Convert Units for output
+
+		$actpress = $actpressmb*$in_per_mb;
+		$densalt = $densaltzm*$ft_per_m;
+
+		if ( $densalt > 36090 || $densalt < -15000 )	{
+			
+			var_dump ("Out of range for Troposhere Algorithm: Altitude =" . round($densalt,0) . " feet" );
+			return;
+		}
+
+		var_dump("Absolute Pressure ".round($actpress,3));
+		var_dump("Density altitude ".round($densalt,0));
+		var_dump("Relative Density ".round($relden,2));
+
+	}
+	
+	
+	
+	
+	
+	
+	
+	
+	
+	
+	
+	
+	
+	
+	
+
+
+
  	
    protected function do_images($icao) {
 	   $airport_images = array();


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