starainrt
3ffdbe0034
- 新增日食、月食、本地可见性、中心线、半影区域、SVG 图示与沙罗周期信息 - 新增行星冲合、留、方照、物理星历、视直径、相位、亮肢角、轨道节点等计算 - 新增木星伽利略卫星位置、现象与接触事件计算 - 新增恒星星表、星座判定、自行修正与观测辅助能力 - 新增 coord、formula、orbit、sundial、lite/sun、lite/moon 等扩展包 - 完善农历年号、月相英文别名、视差角、大气质量、折射、日晷与双星计算 - 增加 NASA、JPL Horizons、IMCCE 等回归测试数据与基线测试 - 重构基础算法文件组织，补充大量公开 API 注释和语义回归测试 - 更新中文和英文 README，补充示例、精度说明、SVG 配图
224 lines
6.2 KiB
Go
224 lines
6.2 KiB
Go
package basic
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import (
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"math"
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"b612.me/astro/planet"
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. "b612.me/astro/tools"
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)
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func SaturnL(jd float64) float64 {
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return planet.WherePlanet(5, 0, jd)
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}
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func SaturnB(jd float64) float64 {
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return planet.WherePlanet(5, 1, jd)
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}
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func SaturnR(jd float64) float64 {
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return planet.WherePlanet(5, 2, jd)
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}
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func ASaturnX(jd float64) float64 {
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l := SaturnL(jd)
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b := SaturnB(jd)
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r := SaturnR(jd)
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el := planet.WherePlanet(-1, 0, jd)
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eb := planet.WherePlanet(-1, 1, jd)
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er := planet.WherePlanet(-1, 2, jd)
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x := r*Cos(b)*Cos(l) - er*Cos(eb)*Cos(el)
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return x
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}
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func ASaturnY(jd float64) float64 {
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l := SaturnL(jd)
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b := SaturnB(jd)
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r := SaturnR(jd)
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el := planet.WherePlanet(-1, 0, jd)
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eb := planet.WherePlanet(-1, 1, jd)
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er := planet.WherePlanet(-1, 2, jd)
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y := r*Cos(b)*Sin(l) - er*Cos(eb)*Sin(el)
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return y
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}
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func ASaturnZ(jd float64) float64 {
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//l := SaturnL(jd)
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b := SaturnB(jd)
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r := SaturnR(jd)
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// el := planet.WherePlanet(-1, 0, jd)
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eb := planet.WherePlanet(-1, 1, jd)
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er := planet.WherePlanet(-1, 2, jd)
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z := r*Sin(b) - er*Sin(eb)
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return z
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}
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func ASaturnXYZ(jd float64) (float64, float64, float64) {
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l := SaturnL(jd)
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b := SaturnB(jd)
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r := SaturnR(jd)
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el := planet.WherePlanet(-1, 0, jd)
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eb := planet.WherePlanet(-1, 1, jd)
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er := planet.WherePlanet(-1, 2, jd)
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x := r*Cos(b)*Cos(l) - er*Cos(eb)*Cos(el)
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y := r*Cos(b)*Sin(l) - er*Cos(eb)*Sin(el)
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z := r*Sin(b) - er*Sin(eb)
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return x, y, z
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}
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func SaturnApparentRa(jd float64) float64 {
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lo, bo := SaturnApparentLoBo(jd)
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eps := TrueObliquity(jd)
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ra := math.Atan2((Sin(lo)*Cos(eps) - Tan(bo)*Sin(eps)), Cos(lo))
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ra = ra * 180 / math.Pi
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return Limit360(ra)
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}
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func SaturnApparentDec(jd float64) float64 {
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lo, bo := SaturnApparentLoBo(jd)
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eps := TrueObliquity(jd)
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dec := ArcSin(Sin(bo)*Cos(eps) + Cos(bo)*Sin(eps)*Sin(lo))
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return dec
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}
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func SaturnApparentRaDec(jd float64) (float64, float64) {
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lo, bo := SaturnApparentLoBo(jd)
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eps := TrueObliquity(jd)
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ra := math.Atan2((Sin(lo)*Cos(eps) - Tan(bo)*Sin(eps)), Cos(lo))
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ra = ra * 180 / math.Pi
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dec := ArcSin(Sin(bo)*Cos(eps) + Cos(bo)*Sin(eps)*Sin(lo))
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return Limit360(ra), dec
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}
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func EarthSaturnAway(jd float64) float64 {
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x, y, z := ASaturnXYZ(jd)
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to := math.Sqrt(x*x + y*y + z*z)
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return to
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}
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func SaturnApparentLo(jd float64) float64 {
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x, y, z := ASaturnXYZ(jd)
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to := 0.0057755183 * math.Sqrt(x*x+y*y+z*z)
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x, y, z = ASaturnXYZ(jd - to)
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lo := math.Atan2(y, x)
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bo := math.Atan2(z, math.Sqrt(x*x+y*y))
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lo = lo * 180 / math.Pi
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bo = bo * 180 / math.Pi
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lo = Limit360(lo)
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//lo-=GXCLo(lo,bo,jd)/3600;
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//bo+=GXCBo(lo,bo,jd);
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lo += Nutation2000Bi(jd)
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return lo
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}
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func SaturnApparentBo(jd float64) float64 {
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x, y, z := ASaturnXYZ(jd)
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to := 0.0057755183 * math.Sqrt(x*x+y*y+z*z)
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x, y, z = ASaturnXYZ(jd - to)
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//lo := math.Atan2(y, x)
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bo := math.Atan2(z, math.Sqrt(x*x+y*y))
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//lo = lo * 180 / math.Pi
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bo = bo * 180 / math.Pi
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//lo+=GXCLo(lo,bo,jd);
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//bo+=GXCBo(lo,bo,jd)/3600;
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//lo+=Nutation2000Bi(jd);
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return bo
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}
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func SaturnApparentLoBo(jd float64) (float64, float64) {
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x, y, z := ASaturnXYZ(jd)
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to := 0.0057755183 * math.Sqrt(x*x+y*y+z*z)
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x, y, z = ASaturnXYZ(jd - to)
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lo := math.Atan2(y, x)
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bo := math.Atan2(z, math.Sqrt(x*x+y*y))
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lo = lo * 180 / math.Pi
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bo = bo * 180 / math.Pi
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lo = Limit360(lo)
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//lo-=GXCLo(lo,bo,jd)/3600;
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//bo+=GXCBo(lo,bo,jd);
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lo += Nutation2000Bi(jd)
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return lo, bo
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}
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func SaturnMag(jd float64) float64 {
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return SaturnMagN(jd, -1)
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}
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func SaturnHeight(jde, lon, lat, timezone float64) float64 {
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// 转换为世界时
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utcJde := jde - timezone/24.0
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// 计算视恒星时
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ra, dec := SaturnApparentRaDec(TD2UT(utcJde, true))
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st := Limit360(ApparentSiderealTime(utcJde)*15 + lon)
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// 计算时角
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hourAngle := Limit360(st - ra)
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// 高度角、时角与天球座标三角转换公式
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// sin(h)=sin(lat)*sin(dec)+cos(dec)*cos(lat)*cos(hourAngle)
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sinHeight := Sin(lat)*Sin(dec) + Cos(dec)*Cos(lat)*Cos(hourAngle)
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return ArcSin(sinHeight)
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}
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func SaturnAzimuth(jde, lon, lat, timezone float64) float64 {
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// 转换为世界时
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utcJde := jde - timezone/24.0
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// 计算视恒星时
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ra, dec := SaturnApparentRaDec(TD2UT(utcJde, true))
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st := Limit360(ApparentSiderealTime(utcJde)*15 + lon)
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// 计算时角
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hourAngle := Limit360(st - ra)
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// 三角转换公式
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tanAzimuth := Sin(hourAngle) / (Cos(hourAngle)*Sin(lat) - Tan(dec)*Cos(lat))
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azimuth := ArcTan(tanAzimuth)
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if azimuth < 0 {
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if hourAngle/15 < 12 {
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return azimuth + 360
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}
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return azimuth + 180
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}
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if hourAngle/15 < 12 {
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return azimuth + 180
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}
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return azimuth
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}
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func SaturnHourAngle(jd, lon, timezone float64) float64 {
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siderealLongitude := Limit360(ApparentSiderealTime(jd-timezone/24)*15 + lon)
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hourAngle := siderealLongitude - SaturnApparentRa(TD2UT(jd-timezone/24.0, true))
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if hourAngle < 0 {
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hourAngle += 360
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}
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return hourAngle
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}
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func SaturnCulminationTime(jde, lon, timezone float64) float64 {
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//jde 世界时，非力学时，当地时区 0时，无需转换力学时
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//ra,dec 瞬时天球座标，非J2000等时间天球坐标
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jde = math.Floor(jde) + 0.5
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estimateJD := jde + Limit360(360-SaturnHourAngle(jde, lon, timezone))/15.0/24.0*0.99726851851851851851
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normalizedHourAngle := func(jde, lon, timezone float64) float64 {
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currentHourAngle := SaturnHourAngle(jde, lon, timezone)
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if currentHourAngle < 180 {
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currentHourAngle += 360
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}
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return currentHourAngle
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}
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for {
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prevJD := estimateJD
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hourAngleDelta := normalizedHourAngle(prevJD, lon, timezone) - 360
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hourAngleSlope := (normalizedHourAngle(prevJD+0.000005, lon, timezone) - normalizedHourAngle(prevJD-0.000005, lon, timezone)) / 0.00001
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estimateJD = prevJD - hourAngleDelta/hourAngleSlope
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if math.Abs(estimateJD-prevJD) <= 0.00001 {
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break
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}
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}
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return estimateJD
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}
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func SaturnRiseTime(jd, lon, lat, timezone, aeroCorrection, observerHeight float64) (float64, error) {
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return saturnRiseDown(jd, lon, lat, timezone, aeroCorrection, observerHeight, true)
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}
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func SaturnSetTime(jd, lon, lat, timezone, aeroCorrection, observerHeight float64) (float64, error) {
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return saturnRiseDown(jd, lon, lat, timezone, aeroCorrection, observerHeight, false)
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}
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func saturnRiseDown(jd, lon, lat, timezone, aeroCorrection, observerHeight float64, isRise bool) (float64, error) {
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return planetRiseDown(jd, lon, lat, timezone, aeroCorrection, observerHeight, isRise, SaturnCulminationTime, SaturnHeight, SaturnApparentDec)
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}
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