Jak na převod souřadnic z S-JTSK do Lat/Long formátu

    function calc($x,$y,$h=200){                
        /*Vypocet zemepisnych souradnic z rovinnych souradnic*/
        $a=6377397.15508; 
        $e=0.081696831215303;
        $n=0.97992470462083; 
        $konst_u_ro=12310230.12797036;
        $sinUQ=0.863499969506341; 
        $cosUQ=0.504348889819882;
        $sinVQ=0.420215144586493; 
        $cosVQ=0.907424504992097;
        $alfa=1.000597498371542; 
        $k=1.003419163966575;
        $ro=sqrt($x*$x+$y*$y);
        $epsilon=2*atan($y/($ro+$x));
        $D=$epsilon/$n; 
        $S=2*atan(exp(1/$n*log($konst_u_ro/$ro)))-M_PI_2;
        $sinS=sin($S);
        $cosS=cos($S);
        $sinU=$sinUQ*$sinS-$cosUQ*$cosS*cos($D);
        $cosU=sqrt(1-$sinU*$sinU);
        $sinDV=sin($D)*$cosS/$cosU; 
        $cosDV=sqrt(1-$sinDV*$sinDV);
        $sinV=$sinVQ*$cosDV-$cosVQ*$sinDV; 
        $cosV=$cosVQ*$cosDV+$sinVQ*$sinDV;
        $Ljtsk=2*atan($sinV/(1+$cosV))/$alfa;
        $t=exp(2/$alfa*log((1+$sinU)/$cosU/$k));
        $pom=($t-1)/($t+1);
        do {
            $sinB=$pom;
            $pom=$t*exp($e*log((1+$e*$sinB)/(1-$e*$sinB))); 
            $pom=($pom-1)/($pom+1);
        } 
        while (abs($pom-$sinB)>0.000000000000001);
        $Bjtsk=atan($pom/sqrt(1-$pom*$pom));
    
    
        /* Pravoúhlé souřadnice ve S-JTSK */   
        $a=6377397.15508; 
        $f_1=299.152812853;
        $e2=1-(1-1/$f_1)*(1-1/$f_1); 
        $ro=$a/sqrt(1-$e2*sin($Bjtsk)*sin($Bjtsk));
        $x=($ro+$H)*cos($Bjtsk)*cos($Ljtsk);  
        $y=($ro+$H)*cos($Bjtsk)*sin($Ljtsk);  
        $z=((1-$e2)*$ro+$H)*sin($Bjtsk);
        
        /* Pravoúhlé souřadnice v WGS-84*/
        $dx=570.69; 
        $dy=85.69; 
        $dz=462.84; 
        $wz=-5.2611/3600*M_PI/180;
        $wy=-1.58676/3600*M_PI/180;
        $wx=-4.99821/3600*M_PI/180; 
        $m=3.543*pow(10,-6); 
        $xn=$dx+(1+$m)*($x+$wz*$y-$wy*$z); 
        $yn=$dy+(1+$m)*(-$wz*$x+$y+$wx*$z); 
        $zn=$dz+(1+$m)*($wy*$x-$wx*$y+$z);
        /* Geodetické souřadnice v systému WGS-84*/
        $a=6378137.0; 
        $f_1=298.257223563;
        $a_b=$f_1/($f_1-1); 
        $p=sqrt($xn*$xn+$yn*$yn); 
        $e2=1-(1-1/$f_1)*(1-1/$f_1);
        $theta=atan($zn*$a_b/$p); 
        $st=sin($theta); 
        $ct=cos($theta);
        $t=($zn+$e2*$a_b*$a*$st*$st*$st)/($p-$e2*$a*$ct*$ct*$ct);
        $B=atan($t);  
        $L=2*atan($yn/($p+$xn));  
        $H=sqrt(1+$t*$t)*($p-$a/sqrt(1+(1-$e2)*$t*$t));
    
        /* Formát výstupních hodnot */   
        $B=$B/M_PI*180;                   
        //$sirka="N";
        if ($B<0){
            $B=-$B; 
            //$sirka="S";
        }
        $stsirky=floor($B);  
        $B=($B-$stsirky)*60; 
        $minsirky=floor($B);
        $B=($B-$minsirky)*60; 
        $vtsirky=round($B*1000)/1000;
        //$sirka=$sirka+$stsirky+"°"+$minsirky+"'"+$vtsirky;
        $gps = $stsirky.' '.$minsirky.' '.$vtsirky;
        
        $L=$L/M_PI*180;  
        //$delka="E";         
        if ($L<0){
            $L=-$L; 
            //$delka="W";
        }
        $stdelky=floor($L);  
        $L=($L-$stdelky)*60; 
        $mindelky=floor($L);
        $L=($L-$mindelky)*60; 
        $vtdelky=round($L*1000)/1000;
        //$delka=$delka+$stdelky+"°"+$mindelky+"'"+$vtdelky;
        $gps .= ' '.$stdelky.' '.$mindelky.' '.$vtdelky;
        
        return $gps;
    }