方位角和高度角

pkg/producer/angle.go

@@ -0,0 +1,42 @@
+package producer
+
+import (
+	"math"
+	"time"
+
+	"github.com/starainrt/astro/sun"
+)
+
+// Azimuth 太阳方位角
+// 返回给定经纬度、对应date时区date时刻的太阳方位角（正北为0，向东增加）
+func SunAzimuth(date time.Time, lon, lat float64) float64 {
+	return sun.Azimuth(date, lon, lat)
+}
+
+// Zenith 太阳高度角
+// 返回给定经纬度、对应date时区date时刻的太阳高度角
+func SunZenith(date time.Time, lon, lat float64) float64 {
+	return sun.Zenith(date, lon, lat)
+}
+
+func SatAzimuth(lon, lat, lonSat, latSat float64) float64 {
+	lon = lon * math.Pi / 180
+	lat = lat * math.Pi / 180
+	lonSat = lonSat * math.Pi / 180
+	latSat = latSat * math.Pi / 180
+
+	beta := math.Acos(math.Cos(lat-latSat) * math.Cos(lon-lonSat))
+	phi := math.Asin(math.Sin(lonSat-lon) / math.Sin(beta))
+	return phi * 180 / math.Pi
+}
+
+func SatZenith(lon, lat, lonSat, latSat float64) float64 {
+	lon = lon * math.Pi / 180
+	lat = lat * math.Pi / 180
+	lonSat = lonSat * math.Pi / 180
+	latSat = latSat * math.Pi / 180
+
+	beta := math.Acos(math.Cos(lat-latSat) * math.Cos(lon-lonSat))
+	theta := math.Asin(42164.0 * math.Sin(beta) / math.Sqrt(1.8084*1e9-5.3725*1e8*math.Cos(beta)))
+	return theta * 180 / math.Pi
+}