|
|
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)
|
|
|
}
|