Files
astro/basic/lunar_eclipse_geometry_test.go
T
b612 16c62a97d5 feat: 完善时标与天象几何计算并扩展输出接口
- 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
2026-09-23 18:55:12 +08:00

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package basic
import (
"math"
"testing"
"time"
)
// Axis 与 Gamma 是同一个量的两种刻度:Gamma × 月球处的地球视差 = Axis。
func TestLunarEclipseShadowGeometryAxisMatchesGamma(t *testing.T) {
for _, date := range []time.Time{
time.Date(2025, time.March, 14, 0, 0, 0, 0, time.UTC),
time.Date(2026, time.March, 3, 0, 0, 0, 0, time.UTC),
time.Date(2028, time.July, 6, 0, 0, 0, 0, time.UTC),
} {
result := LunarEclipse(UTC2TT(Date2JD(date)))
geometry := LunarEclipseShadowGeometryAt(result.Maximum)
// 影几何内部用的是小角近似的地球视差(R⊕/月距),这里必须用同一形式,否则二级差会露出来。
earthParallaxDegrees := (1 / geometry.MoonDistanceEarthRadii) * 180 / math.Pi
if delta := geometry.Gamma*earthParallaxDegrees - geometry.AxisDegrees; math.Abs(delta) > 1e-9 {
t.Fatalf("%s: Gamma×parallax - Axis = %g", date.Format("2006-01-02"), delta)
}
}
}
// 食分公式反解出的月心到影轴距离必须等于 Axis:这条把影几何与食分求解器对起来。
// 食分 = (影半径 + 月视半径 − Axis) / (2 × 月视半径)。
func TestLunarEclipseMagnitudeInvertsToAxis(t *testing.T) {
for _, date := range []time.Time{
time.Date(2025, time.March, 14, 0, 0, 0, 0, time.UTC),
time.Date(2026, time.March, 3, 0, 0, 0, 0, time.UTC),
time.Date(2028, time.July, 6, 0, 0, 0, 0, time.UTC),
time.Date(2020, time.November, 30, 0, 0, 0, 0, time.UTC),
} {
result := LunarEclipse(UTC2TT(Date2JD(date)))
geometry := LunarEclipseShadowGeometryAt(result.Maximum)
moonSemidiameter := MoonSemidiameter(result.Maximum) / 3600
fromUmbral := geometry.UmbralRadiusDegrees + moonSemidiameter -
2*moonSemidiameter*result.Magnitude
fromPenumbral := geometry.PenumbralRadiusDegrees + moonSemidiameter -
2*moonSemidiameter*result.PenumbralMagnitude
t.Logf("%s %s: Axis=%.4f 本影反推=%.4f 半影反推=%.4f",
date.Format("2006-01-02"), result.Type, geometry.AxisDegrees, fromUmbral, fromPenumbral)
if math.Abs(fromUmbral-geometry.AxisDegrees) > 0.002 {
t.Fatalf("%s: umbral magnitude implies axis %.4f, geometry gives %.4f",
date.Format("2006-01-02"), fromUmbral, geometry.AxisDegrees)
}
if math.Abs(fromPenumbral-geometry.AxisDegrees) > 0.002 {
t.Fatalf("%s: penumbral magnitude implies axis %.4f, geometry gives %.4f",
date.Format("2006-01-02"), fromPenumbral, geometry.AxisDegrees)
}
}
}