var pi = 3.14159265358979;
    
    /* Ellipsoid model constants (actual values here are for ED50) */
   
    var sm_a = 6378388;//sono stati commentati i valori relativi all'ellissoide ED50
    var sm_b = 6356911.946;//
    var sm_EccSquared =6.7226700223e-03;//

   
    /* Ellipsoid model constants (actual values here are for WGS84) */
    
    var sm_a = 6378137.0;
    var sm_b = 6356752.314;
    var sm_EccSquared = 6.69437999013e-03;
    
    
    /* Ellipsoid model constants (actual values here are for Roma 40) */
    /*
    var sm_a = 6378388;
    var sm_b = 6356911.946;
    var sm_EccSquared = 8.199188998e-02;
    */
    
    
    
    var UTMScaleFactor = 0.9996;
    var latlon = new Array(2);
    var xy = new Array(2);
    
    
    

function DegToRad (deg)
   {
        return (deg / 180.0 * pi)
 }


function RadToDeg (rad)
   {
        return (rad / pi * 180.0)
 }


    /*
    * FootpointLatitude
    *
    * Computes the footpoint latitude for use in converting transverse
    * Mercator coordinates to ellipsoidal coordinates.
    *
    * Reference: Hoffmann-Wellenhof, B., Lichtenegger, H., and Collins, J.,
    *   GPS: Theory and Practice, 3rd ed.  New York: Springer-Verlag Wien, 1994.
    *
    * Inputs:
    *   y - The UTM northing coordinate, in meters.
    *
    * Returns:
    *   The footpoint latitude, in radians.
    *
    */
    function FootpointLatitude (y)
    {
        var y_, alpha_, beta_, gamma_, delta_, epsilon_, n;
        var result;
        
        /* Precalculate n (Eq. 10.18) */
        n = (sm_a - sm_b) / (sm_a + sm_b);
        	
        /* Precalculate alpha_ (Eq. 10.22) */
        /* (Same as alpha in Eq. 10.17) */
        alpha_ = ((sm_a + sm_b) / 2.0)
            * (1 + (Math.pow (n, 2.0) / 4) + (Math.pow (n, 4.0) / 64));
        
        /* Precalculate y_ (Eq. 10.23) */
        y_ = y / alpha_;
        
        /* Precalculate beta_ (Eq. 10.22) */
        beta_ = (3.0 * n / 2.0) + (-27.0 * Math.pow (n, 3.0) / 32.0)
            + (269.0 * Math.pow (n, 5.0) / 512.0);
        
        /* Precalculate gamma_ (Eq. 10.22) */
        gamma_ = (21.0 * Math.pow (n, 2.0) / 16.0)
            + (-55.0 * Math.pow (n, 4.0) / 32.0);
        	
        /* Precalculate delta_ (Eq. 10.22) */
        delta_ = (151.0 * Math.pow (n, 3.0) / 96.0)
            + (-417.0 * Math.pow (n, 5.0) / 128.0);
        	
        /* Precalculate epsilon_ (Eq. 10.22) */
        epsilon_ = (1097.0 * Math.pow (n, 4.0) / 512.0);
        	
        /* Now calculate the sum of the series (Eq. 10.21) */
        result = y_ + (beta_ * Math.sin (2.0 * y_))
            + (gamma_ * Math.sin (4.0 * y_))
            + (delta_ * Math.sin (6.0 * y_))
            + (epsilon_ * Math.sin (8.0 * y_));
        
        return result;
    }
      
function ArcLengthOfMeridian (phi)
    {
        var alpha, beta, gamma, delta, epsilon, n;
        var result;

        /* Precalculate n */
        n = (sm_a - sm_b) / (sm_a + sm_b);

        /* Precalculate alpha */
        alpha = ((sm_a + sm_b) / 2.0)
           * (1.0 + (Math.pow (n, 2.0) / 4.0) + (Math.pow (n, 4.0) / 64.0));

        /* Precalculate beta */
        beta = (-3.0 * n / 2.0) + (9.0 * Math.pow (n, 3.0) / 16.0)
           + (-3.0 * Math.pow (n, 5.0) / 32.0);

        /* Precalculate gamma */
        gamma = (15.0 * Math.pow (n, 2.0) / 16.0)
            + (-15.0 * Math.pow (n, 4.0) / 32.0);
    
        /* Precalculate delta */
        delta = (-35.0 * Math.pow (n, 3.0) / 48.0)
            + (105.0 * Math.pow (n, 5.0) / 256.0);
    
        /* Precalculate epsilon */
        epsilon = (315.0 * Math.pow (n, 4.0) / 512.0);
    
    /* Now calculate the sum of the series and return */
    result = alpha
        * (phi + (beta * Math.sin (2.0 * phi))
            + (gamma * Math.sin (4.0 * phi))
            + (delta * Math.sin (6.0 * phi))
            + (epsilon * Math.sin (8.0 * phi)));

    return result;
    }

 function UTM2LL (x,y,fuso)
    {        

        var southhemi;
		southhemi=false;
        
        var cmeridian;
        	
        x -= 500000.0;
        x /= UTMScaleFactor;
        	
        /* If in southern hemisphere, adjust y accordingly. */
        if (southhemi)
        y -= 10000000.0;
        		
        y /= UTMScaleFactor;
        
        lambda0 = DegToRad (-183.0 + (fuso * 6.0));
     
        var phif, Nf, Nfpow, nuf2, ep2, tf, tf2, tf4, cf;
        var x1frac, x2frac, x3frac, x4frac, x5frac, x6frac, x7frac, x8frac;
        var x2poly, x3poly, x4poly, x5poly, x6poly, x7poly, x8poly;
    	
        /* Get the value of phif, the footpoint latitude. */
        phif = FootpointLatitude (y);
        	
        /* Precalculate ep2 */
        ep2 = (Math.pow (sm_a, 2.0) - Math.pow (sm_b, 2.0))
              / Math.pow (sm_b, 2.0);
        	
        /* Precalculate cos (phif) */
        cf = Math.cos (phif);
        	
        /* Precalculate nuf2 */
        nuf2 = ep2 * Math.pow (cf, 2.0);
        	
        /* Precalculate Nf and initialize Nfpow */
        Nf = Math.pow (sm_a, 2.0) / (sm_b * Math.sqrt (1 + nuf2));
        Nfpow = Nf;
        	
        /* Precalculate tf */
        tf = Math.tan (phif);
        tf2 = tf * tf;
        tf4 = tf2 * tf2;
        
        /* Precalculate fractional coefficients for x**n in the equations
           below to simplify the expressions for latitude and longitude. */
        x1frac = 1.0 / (Nfpow * cf);
        
        Nfpow *= Nf;   /* now equals Nf**2) */
        x2frac = tf / (2.0 * Nfpow);
        
        Nfpow *= Nf;   /* now equals Nf**3) */
        x3frac = 1.0 / (6.0 * Nfpow * cf);
        
        Nfpow *= Nf;   /* now equals Nf**4) */
        x4frac = tf / (24.0 * Nfpow);
        
        Nfpow *= Nf;   /* now equals Nf**5) */
        x5frac = 1.0 / (120.0 * Nfpow * cf);
        
        Nfpow *= Nf;   /* now equals Nf**6) */
        x6frac = tf / (720.0 * Nfpow);
        
        Nfpow *= Nf;   /* now equals Nf**7) */
        x7frac = 1.0 / (5040.0 * Nfpow * cf);
        
        Nfpow *= Nf;   /* now equals Nf**8) */
        x8frac = tf / (40320.0 * Nfpow);
        
        /* Precalculate polynomial coefficients for x**n.
           -- x**1 does not have a polynomial coefficient. */
        x2poly = -1.0 - nuf2;
        
        x3poly = -1.0 - 2 * tf2 - nuf2;
        
        x4poly = 5.0 + 3.0 * tf2 + 6.0 * nuf2 - 6.0 * tf2 * nuf2
        	- 3.0 * (nuf2 *nuf2) - 9.0 * tf2 * (nuf2 * nuf2);
        
        x5poly = 5.0 + 28.0 * tf2 + 24.0 * tf4 + 6.0 * nuf2 + 8.0 * tf2 * nuf2;
        
        x6poly = -61.0 - 90.0 * tf2 - 45.0 * tf4 - 107.0 * nuf2
        	+ 162.0 * tf2 * nuf2;
        
        x7poly = -61.0 - 662.0 * tf2 - 1320.0 * tf4 - 720.0 * (tf4 * tf2);
        
        x8poly = 1385.0 + 3633.0 * tf2 + 4095.0 * tf4 + 1575 * (tf4 * tf2);
        	
        /* Calculate latitude */
        latlon[0] = phif + x2frac * x2poly * (x * x)
        	+ x4frac * x4poly * Math.pow (x, 4.0)
        	+ x6frac * x6poly * Math.pow (x, 6.0)
        	+ x8frac * x8poly * Math.pow (x, 8.0);
        	
        /* Calculate longitude */
        latlon[1] = lambda0 + x1frac * x
        	+ x3frac * x3poly * Math.pow (x, 3.0)
        	+ x5frac * x5poly * Math.pow (x, 5.0)
        	+ x7frac * x7poly * Math.pow (x, 7.0);
        	
        	
        	latlon[1]=RadToDeg (latlon[1]);
        	latlon[0]=RadToDeg (latlon[0]);
        
        return latlon;
    }


function LL2UTM (lat,lon,fuso){



        var N, nu2, ep2, t, t2, l;
        var l3coef, l4coef, l5coef, l6coef, l7coef, l8coef;
        var tmp;


       phi=DegToRad (lat);
       lambda = DegToRad (lon);
	   lambda0 = DegToRad (-183.0 + (fuso * 6.0));
    
        /* Precalculate ep2 */
        ep2 = (Math.pow (sm_a, 2.0) - Math.pow (sm_b, 2.0)) / Math.pow (sm_b, 2.0);
    
        /* Precalculate nu2 */
        nu2 = ep2 * Math.pow (Math.cos (phi), 2.0);
    
        /* Precalculate N */
        N = Math.pow (sm_a, 2.0) / (sm_b * Math.sqrt (1 + nu2));
    
        /* Precalculate t */
        t = Math.tan (phi);
        t2 = t * t;
        tmp = (t2 * t2 * t2) - Math.pow (t, 6.0);

        /* Precalculate l */
        l = lambda - lambda0;
    
        /* Precalculate coefficients for l**n in the equations below
           so a normal human being can read the expressions for easting
           and northing
           -- l**1 and l**2 have coefficients of 1.0 */
        l3coef = 1.0 - t2 + nu2;
    
        l4coef = 5.0 - t2 + 9 * nu2 + 4.0 * (nu2 * nu2);
    
        l5coef = 5.0 - 18.0 * t2 + (t2 * t2) + 14.0 * nu2
            - 58.0 * t2 * nu2;
    
        l6coef = 61.0 - 58.0 * t2 + (t2 * t2) + 270.0 * nu2
            - 330.0 * t2 * nu2;
    
        l7coef = 61.0 - 479.0 * t2 + 179.0 * (t2 * t2) - (t2 * t2 * t2);
    
        l8coef = 1385.0 - 3111.0 * t2 + 543.0 * (t2 * t2) - (t2 * t2 * t2);
    
        /* Calculate easting (x) */
        xy[0] = N * Math.cos (phi) * l
            + (N / 6.0 * Math.pow (Math.cos (phi), 3.0) * l3coef * Math.pow (l, 3.0))
            + (N / 120.0 * Math.pow (Math.cos (phi), 5.0) * l5coef * Math.pow (l, 5.0))
            + (N / 5040.0 * Math.pow (Math.cos (phi), 7.0) * l7coef * Math.pow (l, 7.0));
    
        /* Calculate northing (y) */
        xy[1] = ArcLengthOfMeridian (phi)
            + (t / 2.0 * N * Math.pow (Math.cos (phi), 2.0) * Math.pow (l, 2.0))
            + (t / 24.0 * N * Math.pow (Math.cos (phi), 4.0) * l4coef * Math.pow (l, 4.0))
            + (t / 720.0 * N * Math.pow (Math.cos (phi), 6.0) * l6coef * Math.pow (l, 6.0))
            + (t / 40320.0 * N * Math.pow (Math.cos (phi), 8.0) * l8coef * Math.pow (l, 8.0));
    
       /* Adjust easting and northing for UTM system. */
        xy[0] = xy[0] * UTMScaleFactor + 500000.0;
        xy[1] = xy[1] * UTMScaleFactor;
        if (xy[1] < 0.0)
            xy[1] = xy[1] + 10000000.0;

        return xy;
    }
    
function LL2GB (lat,lon){
	var NE = new Array(2);
//costanti
e2=0.0067681702;
c=6397376.633;
A1=111092.0821;
A2=16100.59187;
A4=16.96942;
A6=0.02226;
	
if (lon > 6.457){
	//siamo nel secondo fuso
	Lo=2.54767;
	Yo=2520000;
}else{
  	//siamo nel primo fuso
	Lo=-2.54489;
	Yo=1500000;
}
L1=lon-Lo;
ni1=Math.sqrt(1+e2*Math.pow(Math.cos(lat),2));
Zi=Math.atan(Math.tan(lat)/(Math.cos(ni1)*L1));
ni=Math.sqrt(1+e2*Math.pow(Math.cos(Zi),2));
tmp1= (Math.cos(Zi)*Math.tan(L1)/ni);
tmp2=Math.pow(Math.cos(Zi)*Math.tan(L1)/ni,2);
Y=c*Math.log(tmp1+Math.sqrt(tmp2+1));
NE[0]=A1*Zi-A2*Math.sin(2*Zi)+A4*Math.sin(4*Zi)-A6*Math.sin(6*Zi);
NE[1]=Y+Yo;

return NE;
}