新增恒星相关计算

star/star.go

@@ -1,14 +1,133 @@
 package star
 
 import (
+	"errors"
+	"math"
 	"time"
 
 	"b612.me/astro/basic"
 )
 
+var (
+	ERR_STAR_NEVER_RISE = errors.New("ERROR:极夜，星星在今日永远在地平线下！")
+	ERR_STAR_NEVER_DOWN = errors.New("ERROR:极昼，星星在今日永远在地平线上！")
+)
+
 // Constellation
 // 计算date对应UTC世界时给定Date坐标赤经、赤纬所在的星座
 func Constellation(ra, dec float64, date time.Time) string {
 	jde := basic.Date2JDE(date.UTC())
 	return basic.WhichCst(ra, dec, jde)
 }
+
+//MeanSiderealTime UTC 平恒星时
+func MeanSiderealTime(date time.Time) float64 {
+	return basic.MeanSiderealTime(basic.Date2JDE(date.UTC()))
+}
+
+// ApparentSiderealTime UTC真恒星时
+func ApparentSiderealTime(date time.Time) float64 {
+	return basic.ApparentSiderealTime(basic.Date2JDE(date.UTC()))
+}
+
+// RiseTime 星星升起时间
+//  date, 世界时（忽略此处时区）
+//  ra，Date瞬时赤经
+//  dec，Date瞬时赤纬
+//  lon，经度，东正西负
+//  lat，纬度，北正南负
+//  height，高度
+//  aero,是否进行大气修正
+func RiseTime(date time.Time, ra, dec, lon, lat, height float64, aero bool) (time.Time, error) {
+	var err error
+	if date.Hour() > 12 {
+		date = date.Add(time.Hour * -12)
+	}
+	jde := basic.Date2JDE(date)
+	_, loc := date.Zone()
+	timezone := float64(loc) / 3600.0
+	riseJde := basic.StarRiseTime(jde, ra, dec, lon, lat, height, timezone, aero)
+	if riseJde == -2 {
+		err = ERR_STAR_NEVER_RISE
+	}
+	if riseJde == -1 {
+		err = ERR_STAR_NEVER_DOWN
+	}
+	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
+}
+
+// DownTime 星星升起时间
+//  date, 世界时（忽略此处时区）
+//  ra，Date瞬时赤经
+//  dec，Date瞬时赤纬
+//  lon，经度，东正西负
+//  lat，纬度，北正南负
+//  height，高度
+//  aero,是否进行大气修正
+func DownTime(date time.Time, ra, dec, lon, lat, height float64, aero bool) (time.Time, error) {
+	var err error
+	if date.Hour() > 12 {
+		date = date.Add(time.Hour * -12)
+	}
+	jde := basic.Date2JDE(date)
+	_, loc := date.Zone()
+	timezone := float64(loc) / 3600.0
+	riseJde := basic.StarDownTime(jde, ra, dec, lon, lat, height, timezone, aero)
+	if riseJde == -2 {
+		err = ERR_STAR_NEVER_RISE
+	}
+	if riseJde == -1 {
+		err = ERR_STAR_NEVER_DOWN
+	}
+	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
+}
+
+// HourAngle 恒星时角
+// 返回给定Date赤经、经度、对应date时区date时刻的太阳时角（
+func HourAngle(date time.Time, ra, lon float64) float64 {
+	jde := basic.Date2JDE(date)
+	_, loc := date.Zone()
+	timezone := float64(loc) / 3600.0
+	return basic.StarHourAngle(jde, ra, lon, timezone)
+}
+
+// Azimuth 恒星方位角
+// 返回给定Date赤经赤纬、经纬度、对应date时区date时刻的恒星方位角（正北为0，向东增加）
+func Azimuth(date time.Time, ra, dec, lon, lat float64) float64 {
+	jde := basic.Date2JDE(date)
+	_, loc := date.Zone()
+	timezone := float64(loc) / 3600.0
+	return basic.StarAzimuth(jde, ra, dec, lon, lat, timezone)
+}
+
+// Zenith 恒星高度角
+// 返回给定赤经赤纬、经纬度、对应date时区date时刻的太阳高度角
+func Zenith(date time.Time, ra, dec, lon, lat float64) float64 {
+	jde := basic.Date2JDE(date)
+	_, loc := date.Zone()
+	timezone := float64(loc) / 3600.0
+	return basic.StarAzimuth(jde, ra, dec, lon, lat, timezone)
+}
+
+// CulminationTime 恒星中天时间
+// 返回给定赤经赤纬、经纬度、对应date时区date时刻的太阳中天日期
+func CulminationTime(date time.Time, ra, lon float64) time.Time {
+	jde := basic.Date2JDE(date)
+	if jde-math.Floor(jde) < 0.5 {
+		jde--
+	}
+	_, loc := date.Zone()
+	timezone := float64(loc) / 3600.0
+	calcJde := basic.StarCulminationTime(jde, ra, lon, timezone) - timezone/24.00
+	return basic.JDE2DateByZone(calcJde, date.Location(), false)
+}
+
+// InitStarDatabase 初始化恒星数据库
+func InitStarDatabase() error {
+	return basic.LoadStarData()
+}
+
+//通过恒星HR编号获取恒星参数
+func GetStarDataByHR(hr int) (basic.StarData, error) {
+	return basic.StarDataByHR(hr)
+}

star/star_test.go

@@ -0,0 +1,26 @@
+package star
+
+import (
+	"b612.me/astro/tools"
+	"fmt"
+	"testing"
+	"time"
+)
+
+func TestStar(t *testing.T) {
+	err := InitStarDatabase()
+	if err != nil {
+		t.Fatal(err)
+	}
+	sirius, err := GetStarDataByHR(2491)
+	if err != nil {
+		t.Fatal(err)
+	}
+	fmt.Printf("%+v\n", sirius)
+	now := time.Now()
+	ra, dec := sirius.RaDecByDate(now)
+	fmt.Println(tools.Format(ra/15, 1), tools.Format(dec, 0))
+	fmt.Println(RiseTime(now, ra, dec, 115, 40, 0, true))
+	fmt.Println(CulminationTime(now, ra, 115))
+	fmt.Println(DownTime(now, ra, dec, 115, 40, 0, true))
+}