b612
16c62a97d5
- 新增时标、ΔT 模型、质心时间与 UT1 支持 - 改进日月食、月掩、行星事件及路径边界计算 - 完善恒星三维自行与动态距离传播 - 扩展 SVG、GeoJSON、KML 输出与底层距离换算工具 - 整理中英文手册、示例资源及回归测试
50 lines
1.5 KiB
Go
50 lines
1.5 KiB
Go
package internal
|
|
|
|
import . "b612.me/astro/tools"
|
|
|
|
func SunLo(jde float64) float64 {
|
|
t := (jde - 2451545.0) / 365250.0
|
|
return Limit360(280.4664567 + 360007.6982779*t + 0.03032028*t*t + t*t*t/49931.0 - t*t*t*t/15299.0 - t*t*t*t*t/1988000.0)
|
|
}
|
|
|
|
func SunMeanAnomaly(jde float64) float64 {
|
|
t := (jde - 2451545.0) / 36525.0
|
|
return Limit360(357.5291092 + 35999.0502909*t - 0.0001559*t*t - 0.00000048*t*t*t)
|
|
}
|
|
|
|
func EarthEccentricity(jde float64) float64 {
|
|
t := (jde - 2451545.0) / 36525.0
|
|
return 0.016708617 - 0.000042037*t - 0.0000001236*t*t
|
|
}
|
|
|
|
func SunCenter(jde float64) float64 {
|
|
t := (jde - 2451545.0) / 36525.0
|
|
m := SunMeanAnomaly(jde)
|
|
return (1.9146-0.004817*t-0.000014*t*t)*Sin(m) + (0.019993-0.000101*t)*Sin(2*m) + 0.00029*Sin(3*m)
|
|
}
|
|
|
|
// 本文件以 jde（力学时儒略日）键控；lite 包装层的实参是 UTC 民用 JD，69 s 的历元差远低于轻量公式精度。
|
|
func SunTrueLo(jde float64) float64 {
|
|
return Limit360(SunLo(jde) + SunCenter(jde))
|
|
}
|
|
|
|
func SunApparentLo(jde float64) float64 {
|
|
t := (jde - 2451545.0) / 36525.0
|
|
return Limit360(SunTrueLo(jde) - 0.00569 - 0.00478*Sin(125.04-1934.136*t))
|
|
}
|
|
|
|
func SunDistanceAU(jde float64) float64 {
|
|
c := SunCenter(jde)
|
|
m := SunMeanAnomaly(jde)
|
|
e := EarthEccentricity(jde)
|
|
return 1.000001018 * (1 - e*e) / (1 + e*Cos(m+c))
|
|
}
|
|
|
|
func SunTrueRaDec(jde float64) (float64, float64) {
|
|
return EclipticToEquatorial(jde, SunTrueLo(jde), 0)
|
|
}
|
|
|
|
func SunApparentRaDec(jde float64) (float64, float64) {
|
|
return EclipticToEquatorial(jde, SunApparentLo(jde), 0)
|
|
}
|