21 lines
694 B
Go
21 lines
694 B
Go
package star
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import (
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"time"
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"b612.me/astro/basic"
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)
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// ParallacticAngle 恒星视差角（天顶方向角） / stellar parallactic angle.
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//
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// ra/dec 为瞬时赤经赤纬，单位度；lon/lat 为观测者经纬度，东正西负、北正南负。
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// 返回值为有符号视差角，单位度。
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// ra/dec are apparent equatorial coordinates in degrees; lon/lat are east-positive and north-positive.
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// Returns the signed parallactic angle in degrees.
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func ParallacticAngle(date time.Time, ra, dec, lon, lat float64) float64 {
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jde := basic.Date2JDE(date)
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_, loc := date.Zone()
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timezone := float64(loc) / 3600.0
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return basic.StarParallacticAngle(jde, ra, dec, lon, lat, timezone)
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}
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