sunraiseset.html

Javascript实现的计算日出日落的代码。

			timeStr += second;

		return timeStr;
	}


//***********************************************************************/
//* Name:    timeStringShortAMPM							*/
//* Type:    Function									*/
//* Purpose: convert time of day in minutes to a zero-padded string	*/
//*		suitable for printing to the form text fields.  If time	*/
//*		crosses a day boundary, date is appended.				*/
//* Arguments:										*/
//*   minutes : time of day in minutes						*/
//*   JD  : julian day									*/
//* Return value:										*/
//*   string of the format HH:MM[AM/PM] (DDMon)					*/
//***********************************************************************/

// timeStringShortAMPM returns a zero-padded string (HH:MM *M) given time in 
// minutes and appends short date if time is > 24 or < 0, resp.
	// 将分钟转换成HH:MM[AM/PM]格式。
	function timeStringShortAMPM(minutes, JD)
	{
		var julianday = JD;
		var floatHour = minutes / 60.0;
		var hour = Math.floor(floatHour);
		var floatMinute = 60.0 * (floatHour - Math.floor(floatHour));
		var minute = Math.floor(floatMinute);
		var floatSec = 60.0 * (floatMinute - Math.floor(floatMinute));
		var second = Math.floor(floatSec + 0.5);
		var PM = false;

		minute += (second >= 30)? 1 : 0;

		if (minute >= 60) 
		{
			minute -= 60;
			hour ++;
		}

		var daychange = false;
		if (hour > 23) 
		{
			hour -= 24;
			daychange = true;
			julianday += 1.0;
		}

		if (hour < 0)
		{
			hour += 24;
			daychange = true;
			julianday -= 1.0;
		}

		if (hour > 12)
		{
			hour -= 12;
			PM = true;
		}

            if (hour == 12)
		{
              PM = true;
            }

		if (hour == 0)
		{
			PM = false;
			hour = 12;
		}

		var timeStr = hour + ":";
		if (minute < 10)	//	i.e. only one digit
			timeStr += "0" + minute + ((PM)?"PM":"AM");
		else
			timeStr += "" + minute + ((PM)?"PM":"AM");

		if (daychange) return timeStr + " " + calcDayFromJD(julianday);
		return timeStr;
	}


//***********************************************************************/
//* Name:    timeStringAMPMDate							*/
//* Type:    Function									*/
//* Purpose: convert time of day in minutes to a zero-padded string	*/
//*		suitable for printing to the form text fields, and appends	*/
//*		the date.									*/
//* Arguments:										*/
//*   minutes : time of day in minutes						*/
//*   JD  : julian day									*/
//* Return value:										*/
//*   string of the format HH:MM[AM/PM] DDMon					*/
//***********************************************************************/

// timeStringAMPMDate returns a zero-padded string (HH:MM[AM/PM]) given time 
// in minutes and julian day, and appends the short date

	// 将分钟转换成HH:MM[AM/PM]格式。
	function timeStringAMPMDate(minutes, JD)
	{
		var julianday = JD;
		var floatHour = minutes / 60.0;
		var hour = Math.floor(floatHour);
		var floatMinute = 60.0 * (floatHour - Math.floor(floatHour));
		var minute = Math.floor(floatMinute);
		var floatSec = 60.0 * (floatMinute - Math.floor(floatMinute));
		var second = Math.floor(floatSec + 0.5);

		minute += (second >= 30)? 1 : 0;

		if (minute >= 60) 
		{
			minute -= 60;
			hour ++;
		}

		if (hour > 23) 
		{
			hour -= 24;
			julianday += 1.0;
		}

		if (hour < 0)
		{
			hour += 24;
			julianday -= 1.0;
		}

		var PM = false;
		if (hour > 12)
		{
			hour -= 12;
			PM = true;
		}

        if (hour == 12)
		{
            PM = true;
        }

		if (hour == 0)
		{
			PM = false;
			hour = 12;
		}

		var timeStr = hour + ":";
		if (minute < 10)	//	i.e. only one digit
			timeStr += "0" + minute + ((PM)?"PM":"AM");
		else
			timeStr += minute + ((PM)?"PM":"AM");

		return timeStr + " " + calcDayFromJD(julianday);
	}


//***********************************************************************/
//* Name:    timeStringDate								*/
//* Type:    Function									*/
//* Purpose: convert time of day in minutes to a zero-padded 24hr time	*/
//*		suitable for printing to the form text fields.  If time	*/
//*		crosses a day boundary, date is appended.				*/
//* Arguments:										*/
//*   minutes : time of day in minutes						*/
//*   JD  : julian day									*/
//* Return value:										*/
//*   string of the format HH:MM (DDMon)						*/
//***********************************************************************/

// timeStringDate returns a zero-padded string (HH:MM) given time in minutes
// and julian day, and appends the short date if time crosses a day boundary

	// 将分钟转换成HH:MM格式的24小时。
	function timeStringDate(minutes, JD)
	{
		var julianday = JD;
		var floatHour = minutes / 60.0;
		var hour = Math.floor(floatHour);
		var floatMinute = 60.0 * (floatHour - Math.floor(floatHour));
		var minute = Math.floor(floatMinute);
		var floatSec = 60.0 * (floatMinute - Math.floor(floatMinute));
		var second = Math.floor(floatSec + 0.5);

		minute += (second >= 30)? 1 : 0;

		if (minute >= 60) 
		{
			minute -= 60;
			hour ++;
		}

		var daychange = false;
		if (hour > 23) 
		{
			hour -= 24;
			julianday += 1.0;
			daychange = true;
		}

		if (hour < 0)
		{
			hour += 24;
			julianday -= 1.0;
			daychange = true;
		}

		var timeStr = hour + ":";
		if (minute < 10)	//	i.e. only one digit
			timeStr += "0" + minute;
		else
			timeStr += minute;

		if (daychange) return timeStr + " " + calcDayFromJD(julianday);
		return timeStr;
	}

	
//***********************************************************************/
//* Name:    calcSun									*/
//* Type:    Main Function called by form controls				*/
//* Purpose: calculate time of sunrise and sunset for the entered date	*/
//*		and location.  In the special cases near earth's poles, 	*/
//*		the date of nearest sunrise and set are reported.		*/
//* Arguments:										*/
//*   riseSetForm : for displaying results					*/
//*   latLongForm : for reading latitude and longitude data			*/
//*   index : daylight saving yes/no select					*/
//*   index2 : city select index							*/
//* Return value:										*/
//*   none											*/
//*	(fills riseSetForm text fields with results of calculations)	*/
//***********************************************************************/

	// 计算表单中输入的日期和位置的日出日落的时间。
	function calcSun(riseSetForm, latLongForm, index, index2) 
	{
		if(index2 != 0)
		{
			setLatLong(latLongForm, index2);
		}

		var latitude = getLatitude(latLongForm);
		var longitude = getLongitude(latLongForm);
		var indexRS = riseSetForm.mos.selectedIndex
		if (isValidInput(riseSetForm, indexRS, latLongForm)) 
		{
			if((latitude >= -90) && (latitude < -89))
			{
				alert("All latitudes between 89 and 90 S\n will be set to -89");
				latLongForm["latDeg"].value = -89;
				latitude = -89;
			}
			if ((latitude <= 90) && (latitude > 89))
			{
				alert("All latitudes between 89 and 90 N\n will be set to 89");
				latLongForm["latDeg"].value = 89;
				latitude = 89;
			}
			
			//*****	Calculate the time of sunrise			

//*********************************************************************/
//****************   NEW STUFF   ******   一月, 2001   ****************
//*********************************************************************/

			var JD = calcJD(parseFloat(riseSetForm["year"].value), indexRS + 1, parseFloat(riseSetForm["day"].value));
			var dow = calcDayOfWeek(JD);
			var doy = calcDayOfYear(indexRS + 1, parseFloat(riseSetForm["day"].value), isLeapYear(riseSetForm["year"].value));
			var T = calcTimeJulianCent(JD);

			var alpha = calcSunRtAscension(T);
			var theta = calcSunDeclination(T);
			var Etime = calcEquationOfTime(T);

			//riseSetForm["dbug"].value = doy;

//*********************************************************************/

			var eqTime = Etime;
			var solarDec = theta;

			// Calculate sunrise for this date
			// if no sunrise is found, set flag nosunrise

			var nosunrise = false;

			var riseTimeGMT = calcSunriseUTC(JD, latitude, longitude);
			if (!isNumber(riseTimeGMT))
			{
				nosunrise = true;
			}

			// Calculate sunset for this date
			// if no sunset is found, set flag nosunset

			var nosunset = false;
			var setTimeGMT = calcSunsetUTC(JD, latitude, longitude);
			if (!isNumber(setTimeGMT))
			{
				nosunset = true;
			}

			var daySavings = YesNo[index].value;  // = 0 (no) or 60 (yes)
			var zone = latLongForm["hrsToGMT"].value;
			if(zone > 12 || zone < -12.5)
			{
				alert("The offset must be between -12.5 and 12.  \n Setting \"Off-Set\"=0");
				zone = "0";
				latLongForm["hrsToGMT"].value = zone;
			}

			if (!nosunrise)		// Sunrise was found
			{
				var riseTimeLST = riseTimeGMT - (60 * zone) + daySavings;	
					//	in minutes
				var riseStr = timeStringShortAMPM(riseTimeLST, JD);
				var utcRiseStr = timeStringDate(riseTimeGMT, JD);

				riseSetForm["sunrise"].value = riseStr;
				riseSetForm["utcsunrise"].value = utcRiseStr;
			}

			if (!nosunset)		// Sunset was found
			{
				var setTimeLST = setTimeGMT - (60 * zone) + daySavings;
				var setStr = timeStringShortAMPM(setTimeLST, JD);
				var utcSetStr = timeStringDate(setTimeGMT, JD);

				riseSetForm["sunset"].value = setStr;
				riseSetForm["utcsunset"].value = utcSetStr;
			}

			// Calculate solar noon for this date

			var solNoonGMT = calcSolNoonUTC(T, longitude);
			var solNoonLST = solNoonGMT - (60 * zone) + daySavings;

			var solnStr = timeString(solNoonLST);
			var utcSolnStr = timeString(solNoonGMT);

			riseSetForm["solnoon"].value = solnStr;
			riseSetForm["utcsolnoon"].value = utcSolnStr;

			var tsnoon = calcTimeJulianCent(calcJDFromJulianCent(T) -0.5 + solNoonGMT/1440.0); 

			eqTime = calcEquationOfTime(tsnoon);
			solarDec = calcSunDeclination(tsnoon);

			riseSetForm["eqTime"].value = (Math.floor(100*eqTime))/100;
			riseSetForm["solarDec"].value = (Math.floor(100*(solarDec)))/100;
			
			//***********Convert lat and long to standard format
			convLatLong(latLongForm);

			// report special cases of no sunrise

			if(nosunrise)
			{ 
				riseSetForm["utcsunrise"].value = "";
				// if Northern hemisphere and spring or summer, OR  
				// if Southern hemisphere and fall or winter, use 
				// previous sunrise and next sunset

				if ( ((latitude > 66.4) && (doy > 79) && (doy < 267)) ||
				   ((latitude < -66.4) && ((doy < 83) || (doy > 263))) )
				{
					newjd = findRecentSunrise(JD, latitude, longitude);
					newtime = calcSunriseUTC(newjd, latitude, longitude)
						 - (60 * zone) + daySavings;
					if (newtime > 1440)
					{
						newtime -= 1440;
						newjd += 1.