feat: 新增月掩与日月食地理绘图并提升观测计算精度

- 新增月掩恒星和行星：支持搜索、掩甚点、全球掩带及固定地点轨迹计算
- 支持恒星星表坐标转换、有限盘面行星接触事件和月掩 SVG 输出
- 新增日月食及月掩全球投影图、时间标记和 GeoJSON 地理数据接口
- 扩展日食中心线、南北界及偏食足迹采样，支持极区投影
- 修正站心时角、月出月落、月球视半径、折射和恒星自行计算
- 优化内外行星事件搜索、边界选择、极端输入处理和计算稳定性

basic/refraction_test.go

@@ -5,9 +5,17 @@ import (
 	"testing"
 )
 
-func TestRefractionFromApparentAltitudeStandardAtmosphere(t *testing.T) {
-	assertClose(t, "Refraction@0deg", RefractionFromApparentAltitude(0, 1010, 10), 0.483032, 0.0001)
-	assertClose(t, "Refraction@45deg", RefractionFromApparentAltitude(45, 1010, 10), 0.016878, 0.0001)
+func TestRefractionFromTrueAltitudeStandardAtmosphere(t *testing.T) {
+	assertClose(t, "RefractionFromTrue@0deg", RefractionFromTrueAltitude(0, 1010, 10), 0.483032, 0.0001)
+	assertClose(t, "RefractionFromTrue@45deg", RefractionFromTrueAltitude(45, 1010, 10), 0.016878, 0.0001)
+	assertClose(t, "ApparentAltitude@0deg", ApparentAltitude(0, 1010, 10), 0.483032, 0.0001)
+}
+
+func TestRefractionFromApparentAltitudeUsesApparentInput(t *testing.T) {
+	// 视地平线处修正约为 34.5 角分，而不是真高度角公式在 0 度返回的 29 角分 / At the apparent horizon the correction is about 34.5 arcminutes, not
+	// 29 角分 / the 29 arcminutes returned by the true-altitude formula at 0 degrees.
+	assertClose(t, "RefractionFromApparent@0deg", RefractionFromApparentAltitude(0, 1010, 10), 0.574, 0.001)
+	assertClose(t, "TrueAltitude@0deg", TrueAltitude(0, 1010, 10), -0.574, 0.001)
 }
 
 func TestRefractionRoundTrip(t *testing.T) {
@@ -35,29 +43,77 @@ func TestRefractionRoundTrip(t *testing.T) {
 	}
 }
 
+func TestRefractionRoundTripNearZenith(t *testing.T) {
+	for _, trueAltitude := range []float64{89.90, 89.95, 89.99} {
+		apparentAltitude := ApparentAltitude(trueAltitude, 1010, 10)
+		if math.IsNaN(apparentAltitude) || math.IsInf(apparentAltitude, 0) {
+			t.Fatalf("true altitude %.2f produced invalid apparent altitude %v", trueAltitude, apparentAltitude)
+		}
+		got := TrueAltitude(apparentAltitude, 1010, 10)
+		if math.IsNaN(got) || math.IsInf(got, 0) {
+			t.Fatalf("apparent altitude %.12f produced invalid true altitude %v", apparentAltitude, got)
+		}
+		assertClose(t, "NearZenithRoundTrip", got, trueAltitude, 1e-9)
+		if refraction := RefractionFromApparentAltitude(apparentAltitude, 1010, 10); math.IsNaN(refraction) || math.IsInf(refraction, 0) {
+			t.Fatalf("apparent altitude %.12f produced invalid refraction %v", apparentAltitude, refraction)
+		}
+	}
+}
+
+func TestRefractionExtremeTemperatureInverse(t *testing.T) {
+	const (
+		apparentAltitude = 0.0
+		pressureHPa      = 1010.0
+	)
+	trueAltitude := TrueAltitude(apparentAltitude, pressureHPa, -273)
+	if math.IsNaN(trueAltitude) || math.IsInf(trueAltitude, 0) {
+		t.Fatalf("-273 C inverse returned invalid true altitude %v", trueAltitude)
+	}
+	assertClose(t, "ExtremeTemperatureRoundTrip",
+		ApparentAltitude(trueAltitude, pressureHPa, -273), apparentAltitude, 1e-9)
+
+	for _, temperatureC := range []float64{-273.14, math.Nextafter(refractionAbsoluteZeroC, math.Inf(1))} {
+		if got := TrueAltitude(apparentAltitude, pressureHPa, temperatureC); !math.IsNaN(got) {
+			t.Errorf("temperature %.17g C inverse = %v, want NaN when the model has no root", temperatureC, got)
+		}
+		if got := RefractionFromApparentAltitude(apparentAltitude, pressureHPa, temperatureC); !math.IsNaN(got) {
+			t.Errorf("temperature %.17g C apparent refraction = %v, want NaN when the model has no root", temperatureC, got)
+		}
+	}
+}
+
 func TestRefractionScalingAndBounds(t *testing.T) {
-	lowPressure := RefractionFromApparentAltitude(0, 980, 10)
-	highPressure := RefractionFromApparentAltitude(0, 1030, 10)
+	lowPressure := RefractionFromTrueAltitude(0, 980, 10)
+	highPressure := RefractionFromTrueAltitude(0, 1030, 10)
 	if !(lowPressure < highPressure) {
 		t.Fatalf("pressure scaling mismatch: low %.12f high %.12f", lowPressure, highPressure)
 	}
 
-	cold := RefractionFromApparentAltitude(0, 1010, 0)
-	hot := RefractionFromApparentAltitude(0, 1010, 30)
+	cold := RefractionFromTrueAltitude(0, 1010, 0)
+	hot := RefractionFromTrueAltitude(0, 1010, 30)
 	if !(cold > hot) {
 		t.Fatalf("temperature scaling mismatch: cold %.12f hot %.12f", cold, hot)
 	}
 
-	if RefractionFromApparentAltitude(-6, 1010, 10) != 0 {
+	if RefractionFromTrueAltitude(-6, 1010, 10) != 0 {
 		t.Fatalf("refraction below lower limit should be 0")
 	}
-	if RefractionFromApparentAltitude(95, 1010, 10) != 0 {
+	if RefractionFromTrueAltitude(95, 1010, 10) != 0 {
 		t.Fatalf("refraction above upper limit should be 0")
 	}
-	if !math.IsNaN(RefractionFromApparentAltitude(0, 0, 10)) {
+	if !math.IsNaN(RefractionFromTrueAltitude(0, 0, 10)) {
 		t.Fatalf("invalid pressure should produce NaN")
 	}
-	if !math.IsNaN(RefractionFromApparentAltitude(0, 1010, -274)) {
+	if !math.IsNaN(RefractionFromTrueAltitude(0, 1010, -274)) {
 		t.Fatalf("invalid temperature should produce NaN")
 	}
+	if !math.IsNaN(RefractionFromTrueAltitude(0, 1010, -273.15)) {
+		t.Fatalf("absolute zero should produce NaN")
+	}
+	for _, temperatureC := range []float64{-273, -273.14} {
+		refraction := RefractionFromTrueAltitude(0, 1010, temperatureC)
+		if math.IsNaN(refraction) || math.IsInf(refraction, 0) || refraction <= 0 {
+			t.Fatalf("temperature %.2f C produced invalid refraction %v", temperatureC, refraction)
+		}
+	}
 }