272: 
273: function summarytxt(e){
274:     var layer = e.target;
275:     // pcco2=layer.feature.properties.co2pc;
276: 
277:     if (layer.feature.properties.co2pc<emissions){
278:     	ratio=emissions/layer.feature.properties.co2pc;
279:     	stringplus="This flight produces (per passenger) the same amount of greenhouse gases as "+ratio.toFixed(1)+" average resident of "+layer.feature.properties.name +" did in 2017.";
280:     } else {
281:     	ratio=layer.feature.properties.co2pc/emissions;
282:     	stringplus="This average resident of "+layer.feature.properties.name +" produced the same amount of greenhouse gases in 2017 as "+ratio.toFixed(1) +" of these flights (per passenger)";
283:     }
284: 
285:     hoverstring="<span id='hovername'>"+layer.feature.properties.name+":</span> "+layer.feature.properties.co2pc+" tonnes CO<sub>2</sub> per capita<br>"+stringplus;
286: 
345: 
346: //constants for equation
347: shDC=50;
348: lhDC=125;
349: ash=3.87871E-05;
350: alh=0.000134576;
351: bsh=2.9866;
352: csh=1263.42;
353: blh=6.1798;
354: clh=3446.20;
355: Ssh=158.44;
356: Slh=280.39;
357: Plf=0.77;
358: passF=0.951;
359: ecosh=0.96;
360: ecolh=0.8;
361: bussh=1.26;
362: buslh=1.54;
363: fcsh=2.4;
364: fclh=2.4;
365: EF=3.150;
366: pp=0.51;
367: Mnonco2=2;
389: 	eraseErrorMsg();
390: 
391: 	origin=airportdata[fromindex];
392: 	destination=airportdata[toindex];
393: 
394: 	origincoord=[origin.Lat,origin.Long];
395: 	destcoord=[destination.Lat,destination.Long];
396: 
397: 	greatcircledist=getDistance(origincoord,destcoord)/1000; //units of km
398: 
399: 	if (greatcircledist<1500){
400: 		CW=ecosh;
401: 		dist2=greatcircledist+shDC;
402: 		flightdist= (dist2);
403: 		emissions2=((ash*flightdist**2+bsh*flightdist+csh)/(Ssh*Plf))*passF*CW*(EF*Mnonco2+pp)*2/1000;
404: 
405: 	} else {
406: 		CW=ecolh;
407: 		dist2=greatcircledist+lhDC;
408: 		flightdist= (dist2);
409: 		emissions2=((alh*flightdist**2+blh*flightdist+clh)/(Slh*Plf))*passF*CW*(EF*Mnonco2+pp)*2/1000;
410: 
438: 
439: function getDistance(origin, destination) {
440:     // return distance in meters
441:     var lon1 = toRadian(origin[1]),
442:         lat1 = toRadian(origin[0]),
443:         lon2 = toRadian(destination[1]),
444:         lat2 = toRadian(destination[0]);
445: 
446:     var deltaLat = lat2 - lat1;
447:     var deltaLon = lon2 - lon1;
448: 
449:     var a = Math.pow(Math.sin(deltaLat/2), 2) + Math.cos(lat1) * Math.cos(lat2) * Math.pow(Math.sin(deltaLon/2), 2);
450:     var c = 2 * Math.asin(Math.sqrt(a));
451:     var EARTH_RADIUS = 6371;
452:     return c * EARTH_RADIUS * 1000;