feat: 引入可切换星历模型并扩展天象观测链路
- 新增半解析、旧模型、自定义与多源堆叠星历实例，提供 Context、Instance、SPK 读取及状态与视位置计算 - 统一太阳、月球和行星实例接口，扩展黄经穿越、留、相位、最近角距、偕日可见、任意高度升落、轨道节点及凌日等天象查询 - 完善日月食、月掩与凌日的月缘剖面、有限盘面接触、站心修正、局地可见性、全球路径和地图输出 - 新增 SVG、GeoJSON、KML 天象输出及凌日、月掩和月缘地形相关缓存与几何求解 - 新增恒星星表导入与查询，支持 CSV、Hipparcos、BSC5、Stellarium 等格式及名称、交叉标识、锥面检索和星等过滤 - 补充 IAU 2006、地球定向、折射消光、大气观测、轨道传播及半解析行星/月球数据支持 - 将默认未来民用时标切换为 TimeScaleLeapHour，更新 2027–2400 农历速查表、中文日期解析和时区边界处理 - 增加事件基线、跨模型回归、几何边界、月缘地形和输出契约测试，完善中英文手册、示例资源、NOTICE 与忽略规则
This commit is contained in:
+144
-128
@@ -4,6 +4,8 @@ import (
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"math"
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"sort"
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"time"
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"b612.me/astro/internal/iau2006"
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)
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const (
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@@ -18,15 +20,9 @@ const (
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starOccultationMaxContactSteps = 10000
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)
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// FindStarOccultations 搜索单颗点源恒星的月掩星。
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//
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// 输入坐标会从历元传播并转换到当日视坐标系；若提供视差，还会修正观测者的恒星视差。
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// 搜索不会加载内嵌 9100 星表；需要全星表搜索时，调用者必须显式加载并选择恒星。经度东为正、纬度北为正，单位为度；高度为平均海平面以上米数。
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// FindStarOccultations searches for lunar occultations of one point-source star.
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// The input coordinate is propagated from its epoch, converted to the apparent frame of date, and corrected for the observer's stellar parallax when one is supplied.
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// The search does not load the embedded 9100-star catalog; callers that need a catalog-wide search must load and select stars explicitly. Longitude is east-positive in degrees, latitude is north-positive in degrees, and height is the observer elevation above mean sea level in meters.
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func FindStarOccultations(start, end time.Time, star StarCoordinate, longitude, latitude, height float64,
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options OccultationSearchOptions) ([]StarOccultationInfo, error) {
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// FindStarOccultationsWithInstance 用指定星历实例求值；inst 为 nil 时用进程当前模型 / evaluation with an explicit instance; nil uses the process model.
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func FindStarOccultationsWithInstance(start, end time.Time, star StarCoordinate, longitude, latitude, height float64,
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options OccultationSearchOptions, inst *Instance) ([]StarOccultationInfo, error) {
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if err := validateOccultationTimeRange(start, end); err != nil {
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return nil, err
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}
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@@ -45,8 +41,8 @@ func FindStarOccultations(start, end time.Time, star StarCoordinate, longitude,
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endTT := occultationTimeToTT(end)
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resultLocation := start.Location()
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results := make([]StarOccultationInfo, 0)
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for _, greatestTT := range starOccultationCandidateGreatestTimes(startTT, endTT, starOccultationCoarseStepDays(options), star, observer, options.SafetyMarginArcsec) {
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info, ok := starOccultationInfoAtGreatest(greatestTT, star, observer, options.SafetyMarginArcsec, resultLocation)
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for _, greatestTT := range starOccultationCandidateGreatestTimes(startTT, endTT, starOccultationCoarseStepDays(options), star, observer, options.SafetyMarginArcsec, inst) {
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info, ok := starOccultationInfoWithLimb(greatestTT, star, observer, options.SafetyMarginArcsec, resultLocation, options.LunarLimb, inst)
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if !ok {
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continue
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}
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@@ -62,14 +58,8 @@ func FindStarOccultations(start, end time.Time, star StarCoordinate, longitude,
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return results, nil
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}
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// FindBestStarOccultations 返回窗口内每次恒星月掩在地球上的全球几何掩甚点。
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// 返回的 StarOccultationInfo.Observer 是海平面大地测量位置，由月掩几何选择，不使用地平线或可见性评分。
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//
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// 地心数据只用于月周期搜索初值；最终点是与 FindStarOccultationPaths 一致的标准全球掩甚路径点，然后在该处重新进行站心接触和可见性计算。查询端点 10 ms 内的掩甚时刻也会包含，与数值根精度一致。
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// FindBestStarOccultations returns the global geometric greatest point on Earth for each stellar occultation in the window.
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// The returned StarOccultationInfo.Observer is the geodetic location at sea level; it is selected from the occultation geometry, without a horizon or visibility score.
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// Geocentric data only seeds each lunar-month search. The final point is the canonical global greatest-path point, matching FindStarOccultationPaths; event contacts and visibility are then recomputed topocentrically there. A greatest instant within 10 ms of either query endpoint is included, matching the numerical root precision.
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func FindBestStarOccultations(start, end time.Time, star StarCoordinate, options OccultationSearchOptions) ([]StarOccultationInfo, error) {
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// FindBestStarOccultationsWithInstance 用指定星历实例求值；inst 为 nil 时用进程当前模型 / evaluation with an explicit instance; nil uses the process model.
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func FindBestStarOccultationsWithInstance(start, end time.Time, star StarCoordinate, options OccultationSearchOptions, inst *Instance) ([]StarOccultationInfo, error) {
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if err := validateOccultationTimeRange(start, end); err != nil {
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return nil, err
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}
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@@ -88,12 +78,12 @@ func FindBestStarOccultations(start, end time.Time, star StarCoordinate, options
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candidateEndTT := endTT + occultationPathSearchSpanDays
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resultLocation := start.Location()
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results := make([]StarOccultationInfo, 0)
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for _, seedTT := range starOccultationGeocentricCandidateGreatestTimes(candidateStartTT, candidateEndTT, starOccultationCoarseStepDays(options), star, options.SafetyMarginArcsec) {
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greatestTT, observer, _, observerOK := starOccultationBestObserver(seedTT, selectionStartTT, selectionEndTT, star)
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for _, seedTT := range starOccultationGeocentricCandidateGreatestTimes(candidateStartTT, candidateEndTT, starOccultationCoarseStepDays(options), star, options.SafetyMarginArcsec, inst) {
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greatestTT, observer, _, observerOK := starOccultationBestObserver(seedTT, selectionStartTT, selectionEndTT, star, inst)
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if !observerOK {
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continue
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}
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info, ok := starOccultationInfoAtGreatest(greatestTT, star, observer, options.SafetyMarginArcsec, resultLocation)
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info, ok := starOccultationInfoWithLimb(greatestTT, star, observer, options.SafetyMarginArcsec, resultLocation, options.LunarLimb, inst)
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if !ok {
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continue
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}
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@@ -108,40 +98,44 @@ func FindBestStarOccultations(start, end time.Time, star StarCoordinate, options
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return results, nil
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}
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func starOccultationCandidateGreatestTimes(startTT, endTT, step float64, star StarCoordinate, observer Observer, safetyMarginArcsec float64) []float64 {
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func starOccultationCandidateGreatestTimes(startTT, endTT, step float64, star StarCoordinate, observer Observer, safetyMarginArcsec float64, instances ...*Instance) []float64 {
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inst := instanceValue(instances)
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results := make([]float64, 0)
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for cycleStart := startTT; cycleStart < endTT; cycleStart += starOccultationSiderealMonthDays {
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cycleEnd := math.Min(cycleStart+starOccultationSiderealMonthDays, endTT)
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scanStart := math.Max(startTT-step, cycleStart-step)
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scanEnd := math.Min(endTT+step, cycleEnd+step)
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if !starOccultationLatitudeEnvelopePass(scanStart, scanEnd, star, &observer, safetyMarginArcsec) {
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if !starOccultationLatitudeEnvelopePass(scanStart, scanEnd, star, &observer, safetyMarginArcsec, inst) {
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continue
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}
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results = append(results, starOccultationScanCandidates(
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scanStart, scanEnd, step,
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func(tt float64) float64 { return starMoonSeparationArcsec(tt, star, observer) },
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func(tt float64) float64 { return starMoonSeparationArcsec(tt, star, observer, inst) },
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func(tt float64) bool {
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return starOccultationLatitudePass(tt, star, observer, safetyMarginArcsec)
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return starOccultationLatitudePass(tt, star, observer, safetyMarginArcsec, inst)
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},
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)...)
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}
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return uniqueOccultationCandidateTimes(results, startTT, endTT)
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}
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func starOccultationGeocentricCandidateGreatestTimes(startTT, endTT, step float64, star StarCoordinate, safetyMarginArcsec float64) []float64 {
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func starOccultationGeocentricCandidateGreatestTimes(startTT, endTT, step float64, star StarCoordinate, safetyMarginArcsec float64, instances ...*Instance) []float64 {
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inst := instanceValue(instances)
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results := make([]float64, 0)
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for cycleStart := startTT; cycleStart < endTT; cycleStart += starOccultationSiderealMonthDays {
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cycleEnd := math.Min(cycleStart+starOccultationSiderealMonthDays, endTT)
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scanStart := math.Max(startTT-step, cycleStart-step)
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scanEnd := math.Min(endTT+step, cycleEnd+step)
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if !starOccultationLatitudeEnvelopePass(scanStart, scanEnd, star, nil, safetyMarginArcsec) {
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if !starOccultationLatitudeEnvelopePass(scanStart, scanEnd, star, nil, safetyMarginArcsec, inst) {
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continue
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}
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results = append(results, starOccultationScanCandidates(
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scanStart, scanEnd, step,
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func(tt float64) float64 { return starOccultationGeocentricSeparationArcsec(tt, star) },
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func(tt float64) float64 { return starOccultationGeocentricSeparationArcsec(tt, star, inst) },
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func(tt float64) bool {
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return starOccultationLatitudePassGeocentric(tt, star, safetyMarginArcsec)
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return starOccultationLatitudePassGeocentric(tt, star, safetyMarginArcsec, inst)
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},
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)...)
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}
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@@ -216,23 +210,25 @@ func uniqueOccultationCandidateTimes(times []float64, startTT, endTT float64) []
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return unique
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}
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func starOccultationLatitudeEnvelopePass(startTT, endTT float64, star StarCoordinate, observer *Observer, safetyMarginArcsec float64) bool {
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func starOccultationLatitudeEnvelopePass(startTT, endTT float64, star StarCoordinate, observer *Observer, safetyMarginArcsec float64, instances ...*Instance) bool {
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inst := instanceValue(instances)
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minimumLatitude := math.Inf(1)
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maximumLatitude := math.Inf(-1)
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maximumMoonRadiusDeg := 0.0
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for _, tt := range []float64{startTT, (startTT + endTT) / 2, endTT} {
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var ra, dec float64
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if observer == nil {
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ra, dec = starApparentRaDecGeocentric(tt, star)
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ra, dec = starApparentRaDecGeocentric(tt, star, inst)
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} else {
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ra, dec = starApparentRaDec(tt, star, *observer)
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ra, dec = starApparentRaDec(tt, star, *observer, inst)
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}
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_, latitude := RaDecToLoBo(tt, ra, dec)
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minimumLatitude = math.Min(minimumLatitude, latitude)
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maximumLatitude = math.Max(maximumLatitude, latitude)
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moonRadius := MoonSemidiameter(tt)
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moonRadius := MoonSemidiameterWithInstance(tt, inst)
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if observer != nil {
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moonRadius = moonTopocentricSemidiameterN(tt, *observer, -1)
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moonRadius = moonTopocentricSemidiameterN(tt, *observer, -1, inst)
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}
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maximumMoonRadiusDeg = math.Max(maximumMoonRadiusDeg, moonRadius/3600)
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}
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@@ -271,27 +267,31 @@ func starOccultationMinimizeValue(left, right float64, value func(float64) float
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return (left + right) / 2
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}
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func starOccultationGeocentricSeparationArcsec(tt float64, star StarCoordinate) float64 {
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moonRA, moonDec := HMoonGeocentricApparentRaDecN(tt, -1)
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starRA, starDec, _ := starApparentRaDecDistanceGeocentric(tt, star)
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func starOccultationGeocentricSeparationArcsec(tt float64, star StarCoordinate, instances ...*Instance) float64 {
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inst := instanceValue(instances)
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moonRA, moonDec := HMoonGeocentricApparentRaDecNWithInstance(tt, -1, inst)
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starRA, starDec, _ := starApparentRaDecDistanceGeocentric(tt, star, inst)
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return angularSeparationDegrees(moonRA, moonDec, starRA, starDec) * 3600
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}
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func starOccultationBestObserver(seedTT, startTT, endTT float64, star StarCoordinate) (float64, Observer, float64, bool) {
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func starOccultationBestObserver(seedTT, startTT, endTT float64, star StarCoordinate, instances ...*Instance) (float64, Observer, float64, bool) {
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inst := instanceValue(instances)
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searchStart := seedTT - occultationPathSearchSpanDays
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searchEnd := seedTT + occultationPathSearchSpanDays
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outerStart, outerEnd, ok := starOccultationPathWindow(seedTT, searchStart, searchEnd, star, false)
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outerStart, outerEnd, ok := starOccultationPathWindow(seedTT, searchStart, searchEnd, star, false, inst)
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if !ok {
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return 0, Observer{}, 0, false
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}
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greatestTT := starOccultationPathGreatest(seedTT, outerStart, outerEnd, star)
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greatestTT := starOccultationPathGreatest(seedTT, outerStart, outerEnd, star, inst)
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if greatestTT < startTT || greatestTT > endTT {
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return 0, Observer{}, 0, false
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}
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point, pointOK := starOccultationPathCenterPoint(greatestTT, star, time.UTC)
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point, pointOK := starOccultationPathCenterPoint(greatestTT, star, time.UTC, inst)
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if !pointOK {
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frameAt := func(tt float64) (occultationPathFrame, bool) {
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return starOccultationPathFrameAt(tt, star)
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return starOccultationPathFrameAt(tt, star, inst)
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}
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// 同行星最佳事件搜索：非中心路径的最佳站心取离影轴最近的椭球点，
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// 外接触切点位于掩带边缘，只作最后回退。
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@@ -300,15 +300,15 @@ func starOccultationBestObserver(seedTT, startTT, endTT float64, star StarCoordi
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// the outer contact tangent on the band edge stays the last resort.
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point, pointOK = occultationPathTrackPointForFrame(greatestTT, frameAt, time.UTC)
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if !pointOK {
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point, pointOK = occultationPathBoundaryPointForFrame(greatestTT, frameAt, time.UTC)
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point, pointOK = occultationPathBoundaryPointForFrame(greatestTT, frameAt, time.UTC, inst)
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}
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}
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if !pointOK {
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return 0, Observer{}, 0, false
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}
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observer := Observer{Longitude: point.Longitude, Latitude: point.Latitude}
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position := starMoonPositionAt(greatestTT, star, observer)
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moonRadius := moonTopocentricSemidiameterN(greatestTT, observer, -1)
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position := starMoonPositionAt(greatestTT, star, observer, inst)
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moonRadius := moonTopocentricSemidiameterN(greatestTT, observer, -1, inst)
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if !position.valid || !finite(moonRadius) {
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return 0, Observer{}, 0, false
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}
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@@ -316,24 +316,43 @@ func starOccultationBestObserver(seedTT, startTT, endTT float64, star StarCoordi
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return greatestTT, observer, metric, finite(metric)
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}
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func normalizeLongitude180(longitude float64) float64 {
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longitude = math.Mod(longitude+180, 360)
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if longitude < 0 {
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longitude += 360
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func starOccultationInfoAtGreatest(greatestTT float64, star StarCoordinate, observer Observer, safetyMarginArcsec float64, location *time.Location, instances ...*Instance) (StarOccultationInfo, bool) {
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inst := instanceValue(instances)
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info, ok := starOccultationGreatestInfo(greatestTT, star, observer, safetyMarginArcsec, location, inst)
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if !ok || info.MinimumSeparationArcsec > info.MoonSemidiameterArcsec {
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return StarOccultationInfo{}, false
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}
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return longitude - 180
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minimumResidual := info.MinimumSeparationArcsec - info.MoonSemidiameterArcsec
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if math.Abs(minimumResidual) <= starOccultationGrazingTolerance {
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info.Type = OccultationGrazing
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info.Immersion = info.Greatest
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info.Emersion = info.Greatest
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info.ContactsComplete = true
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return info, true
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}
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immersionTT, immersionOK := starOccultationContact(greatestTT, greatestTT-starOccultationContactSpanDays, -1, star, observer, inst)
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emersionTT, emersionOK := starOccultationContact(greatestTT, greatestTT+starOccultationContactSpanDays, 1, star, observer, inst)
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if !immersionOK || !emersionOK {
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return StarOccultationInfo{}, false
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}
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info.Immersion = occultationTTToLocation(immersionTT, location)
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info.Emersion = occultationTTToLocation(emersionTT, location)
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info.ContactsComplete = true
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return info, true
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}
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func starOccultationInfoAtGreatest(greatestTT float64, star StarCoordinate, observer Observer, safetyMarginArcsec float64, location *time.Location) (StarOccultationInfo, bool) {
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if !starOccultationLatitudePass(greatestTT, star, observer, safetyMarginArcsec) {
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// starOccultationGreatestInfo 只填掩甚几何，不判断圆月面是否成掩、不求接触。
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func starOccultationGreatestInfo(greatestTT float64, star StarCoordinate, observer Observer, safetyMarginArcsec float64, location *time.Location, inst *Instance) (StarOccultationInfo, bool) {
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if !starOccultationLatitudePass(greatestTT, star, observer, safetyMarginArcsec, inst) {
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return StarOccultationInfo{}, false
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}
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minimumSeparation := starMoonSeparationArcsec(greatestTT, star, observer)
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moonRadius := moonTopocentricSemidiameterN(greatestTT, observer, -1)
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if !finite(minimumSeparation) || !finite(moonRadius) || minimumSeparation > moonRadius {
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minimumSeparation := starMoonSeparationArcsec(greatestTT, star, observer, inst)
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moonRadius := moonTopocentricSemidiameterN(greatestTT, observer, -1, inst)
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if !finite(minimumSeparation) || !finite(moonRadius) {
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return StarOccultationInfo{}, false
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}
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greatestPosition := starMoonPositionAt(greatestTT, star, observer)
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greatestPosition := starMoonPositionAt(greatestTT, star, observer, inst)
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if !greatestPosition.valid {
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return StarOccultationInfo{}, false
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}
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@@ -349,23 +368,6 @@ func starOccultationInfoAtGreatest(greatestTT float64, star StarCoordinate, obse
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MoonAzimuthAtGreatest: occultationAzimuth(greatestTT, observer, greatestPosition.moonRA, greatestPosition.moonDec),
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}
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info.VisibleAtGreatest = info.MoonAltitudeAtGreatest >= 0
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minimumResidual := minimumSeparation - moonRadius
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if math.Abs(minimumResidual) <= starOccultationGrazingTolerance {
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info.Type = OccultationGrazing
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info.Immersion = info.Greatest
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info.Emersion = info.Greatest
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info.ContactsComplete = true
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return info, true
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}
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immersionTT, immersionOK := starOccultationContact(greatestTT, greatestTT-starOccultationContactSpanDays, -1, star, observer)
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emersionTT, emersionOK := starOccultationContact(greatestTT, greatestTT+starOccultationContactSpanDays, 1, star, observer)
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if !immersionOK || !emersionOK {
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return StarOccultationInfo{}, false
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}
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info.Immersion = occultationTTToLocation(immersionTT, location)
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info.Emersion = occultationTTToLocation(emersionTT, location)
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info.ContactsComplete = true
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return info, true
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}
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@@ -375,9 +377,11 @@ type starMoonPosition struct {
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valid bool
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}
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func starMoonPositionAt(tt float64, star StarCoordinate, observer Observer) starMoonPosition {
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moonRA, moonDec := moonTopocentricApparentRaDec(tt, observer, -1)
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starRA, starDec := starApparentRaDec(tt, star, observer)
|
||||
func starMoonPositionAt(tt float64, star StarCoordinate, observer Observer, instances ...*Instance) starMoonPosition {
|
||||
inst := instanceValue(instances)
|
||||
|
||||
moonRA, moonDec := moonTopocentricApparentRaDec(tt, observer, -1, inst)
|
||||
starRA, starDec := starApparentRaDec(tt, star, observer, inst)
|
||||
return starMoonPosition{
|
||||
moonRA: moonRA,
|
||||
moonDec: moonDec,
|
||||
@@ -387,16 +391,20 @@ func starMoonPositionAt(tt float64, star StarCoordinate, observer Observer) star
|
||||
}
|
||||
}
|
||||
|
||||
func moonTopocentricApparentRaDec(tt float64, observer Observer, n int) (float64, float64) {
|
||||
ra, dec := HMoonGeocentricApparentRaDecN(tt, n)
|
||||
func moonTopocentricApparentRaDec(tt float64, observer Observer, n int, instances ...*Instance) (float64, float64) {
|
||||
inst := instanceValue(instances)
|
||||
|
||||
ra, dec := HMoonGeocentricApparentRaDecNWithInstance(tt, n, inst)
|
||||
ut := TT2UTC(tt)
|
||||
distanceAU := HMoonAwayN(tt, n) / 149597870.7
|
||||
distanceAU := HMoonAwayNWithInstance(tt, n, inst) / 149597870.7
|
||||
ra, dec = TopocentricRaDec(ra, dec, observer.Latitude, observer.Longitude, ut, distanceAU, observer.Height)
|
||||
return normalizeRA(ra), dec
|
||||
}
|
||||
|
||||
func starApparentRaDec(tt float64, star StarCoordinate, observer Observer) (float64, float64) {
|
||||
ra, dec, distanceAU := starApparentRaDecDistanceGeocentric(tt, star)
|
||||
func starApparentRaDec(tt float64, star StarCoordinate, observer Observer, instances ...*Instance) (float64, float64) {
|
||||
inst := instanceValue(instances)
|
||||
|
||||
ra, dec, distanceAU := starApparentRaDecDistanceGeocentric(tt, star, inst)
|
||||
if distanceAU > 0 {
|
||||
ra, dec = TopocentricRaDec(ra, dec, observer.Latitude, observer.Longitude, TT2UTC(tt), distanceAU, observer.Height)
|
||||
ra = normalizeRA(ra)
|
||||
@@ -404,13 +412,17 @@ func starApparentRaDec(tt float64, star StarCoordinate, observer Observer) (floa
|
||||
return ra, dec
|
||||
}
|
||||
|
||||
func starApparentRaDecGeocentric(tt float64, star StarCoordinate) (float64, float64) {
|
||||
ra, dec, _ := starApparentRaDecDistanceGeocentric(tt, star)
|
||||
func starApparentRaDecGeocentric(tt float64, star StarCoordinate, instances ...*Instance) (float64, float64) {
|
||||
inst := instanceValue(instances)
|
||||
|
||||
ra, dec, _ := starApparentRaDecDistanceGeocentric(tt, star, inst)
|
||||
return ra, dec
|
||||
}
|
||||
|
||||
// starApparentRaDecDistanceGeocentric 同时给出视位置与推进后的距离（天文单位，0 表示距离未知）。
|
||||
func starApparentRaDecDistanceGeocentric(tt float64, star StarCoordinate) (float64, float64, float64) {
|
||||
func starApparentRaDecDistanceGeocentric(tt float64, star StarCoordinate, instances ...*Instance) (float64, float64, float64) {
|
||||
inst := instanceValue(instances)
|
||||
|
||||
epochJD := occultationTimeToTT(star.Epoch)
|
||||
parallaxMas := star.parallaxMas()
|
||||
ra := star.RA
|
||||
@@ -419,13 +431,13 @@ func starApparentRaDecDistanceGeocentric(tt float64, star StarCoordinate) (float
|
||||
if star.Frame == CoordinateFrameICRS {
|
||||
ra, dec = starICRSToMeanJ2000RaDec(ra, dec)
|
||||
} else if star.Frame == CoordinateFrameApparentOfDate {
|
||||
ra, dec = starApparentToMeanRaDec(epochJD, ra, dec, parallaxMas)
|
||||
ra, dec = starApparentToMeanRaDec(epochJD, ra, dec, parallaxMas, inst)
|
||||
precessionEpoch = epochJD
|
||||
}
|
||||
epochDistanceAU := starEpochDistanceAU(parallaxMas)
|
||||
ra, dec, distanceAU := starProperMotionRaDec(tt, star, ra, dec, epochDistanceAU)
|
||||
ra, dec = Precess(ra, dec, precessionEpoch, tt)
|
||||
ra, dec = starMeanToApparentRaDec(tt, ra, dec, parallaxMasAtDistance(parallaxMas, distanceAU))
|
||||
ra, dec = starMeanToApparentRaDec(tt, ra, dec, parallaxMasAtDistance(parallaxMas, distanceAU), inst)
|
||||
return ra, dec, distanceAU
|
||||
}
|
||||
|
||||
@@ -493,47 +505,39 @@ func starProperMotionRaDec3D(ra, dec, years, epochDistanceAU float64, star StarC
|
||||
}
|
||||
|
||||
func starICRSToMeanJ2000RaDec(ra, dec float64) (float64, float64) {
|
||||
// IAU SOFA 框架偏差矩阵，将 GCRS/ICRS 向量转换为 J2000.0 平均赤道和春分点。
|
||||
// IAU SOFA frame-bias matrix, transforming a GCRS/ICRS vector to the mean equator and equinox of J2000.0.
|
||||
const (
|
||||
b00 = 0.9999999999999942
|
||||
b01 = -0.7078279744199197e-7
|
||||
b02 = 0.8056217146976134e-7
|
||||
b10 = 0.7078279477857337e-7
|
||||
b11 = 0.9999999999999969
|
||||
b12 = 0.3306041454222148e-7
|
||||
b20 = -0.8056217380986972e-7
|
||||
b21 = -0.3306040883980553e-7
|
||||
b22 = 0.9999999999999962
|
||||
)
|
||||
b := iau2006.FrameBias()
|
||||
raRad := ra * math.Pi / 180
|
||||
decRad := dec * math.Pi / 180
|
||||
x := math.Cos(decRad) * math.Cos(raRad)
|
||||
y := math.Cos(decRad) * math.Sin(raRad)
|
||||
z := math.Sin(decRad)
|
||||
biasedX := b00*x + b01*y + b02*z
|
||||
biasedY := b10*x + b11*y + b12*z
|
||||
biasedZ := b20*x + b21*y + b22*z
|
||||
biasedX := b[0][0]*x + b[0][1]*y + b[0][2]*z
|
||||
biasedY := b[1][0]*x + b[1][1]*y + b[1][2]*z
|
||||
biasedZ := b[2][0]*x + b[2][1]*y + b[2][2]*z
|
||||
return normalizeRA(math.Atan2(biasedY, biasedX) * 180 / math.Pi),
|
||||
math.Atan2(biasedZ, math.Hypot(biasedX, biasedY)) * 180 / math.Pi
|
||||
}
|
||||
|
||||
func starMeanToApparentRaDec(tt, ra, dec, parallaxMas float64) (float64, float64) {
|
||||
func starMeanToApparentRaDec(tt, ra, dec, parallaxMas float64, instances ...*Instance) (float64, float64) {
|
||||
inst := instanceValue(instances)
|
||||
|
||||
longitude, latitude := starMeanEquatorialToEcliptic(tt, ra, dec)
|
||||
if parallaxMas > 0 {
|
||||
longitude, latitude = starAnnualParallaxEcliptic(tt, longitude, latitude, parallaxMas)
|
||||
longitude, latitude = starAnnualParallaxEcliptic(tt, longitude, latitude, parallaxMas, inst)
|
||||
}
|
||||
meanLongitude, meanLatitude := longitude, latitude
|
||||
longitude = normalizeRA(meanLongitude + GXCLo(meanLongitude, meanLatitude, tt)/3600 + Nutation2000Bi(tt))
|
||||
latitude = meanLatitude + GXCBo(meanLongitude, meanLatitude, tt)/3600
|
||||
longitude = normalizeRA(meanLongitude + GXCLoWithInstance(meanLongitude, meanLatitude, tt, inst)/3600 + Nutation2000Bi(tt))
|
||||
latitude = meanLatitude + GXCBoWithInstance(meanLongitude, meanLatitude, tt, inst)/3600
|
||||
ra, dec = LoBoToRaDec(tt, longitude, latitude)
|
||||
return normalizeRA(ra), dec
|
||||
}
|
||||
|
||||
func starApparentToMeanRaDec(tt, apparentRA, apparentDec, parallaxMas float64) (float64, float64) {
|
||||
func starApparentToMeanRaDec(tt, apparentRA, apparentDec, parallaxMas float64, instances ...*Instance) (float64, float64) {
|
||||
inst := instanceValue(instances)
|
||||
|
||||
meanRA, meanDec := apparentRA, apparentDec
|
||||
for i := 0; i < 8; i++ {
|
||||
computedRA, computedDec := starMeanToApparentRaDec(tt, meanRA, meanDec, parallaxMas)
|
||||
computedRA, computedDec := starMeanToApparentRaDec(tt, meanRA, meanDec, parallaxMas, inst)
|
||||
meanRA = normalizeRA(meanRA - signedAngleDifference(computedRA, apparentRA))
|
||||
meanDec -= computedDec - apparentDec
|
||||
}
|
||||
@@ -554,7 +558,9 @@ func starMeanEquatorialToEcliptic(tt, ra, dec float64) (float64, float64) {
|
||||
return normalizeRA(longitude), latitude
|
||||
}
|
||||
|
||||
func starAnnualParallaxEcliptic(tt, longitude, latitude, parallaxMas float64) (float64, float64) {
|
||||
func starAnnualParallaxEcliptic(tt, longitude, latitude, parallaxMas float64, instances ...*Instance) (float64, float64) {
|
||||
inst := instanceValue(instances)
|
||||
|
||||
distanceAU := 206264806.247 / parallaxMas
|
||||
longitudeRad := longitude * math.Pi / 180
|
||||
latitudeRad := latitude * math.Pi / 180
|
||||
@@ -563,8 +569,8 @@ func starAnnualParallaxEcliptic(tt, longitude, latitude, parallaxMas float64) (f
|
||||
starY := distanceAU * cosLatitude * math.Sin(longitudeRad)
|
||||
starZ := distanceAU * math.Sin(latitudeRad)
|
||||
|
||||
earthLongitude := normalizeRA(HSunTrueLoN(tt, -1)+180) * math.Pi / 180
|
||||
earthDistance := EarthAwayN(tt, -1)
|
||||
earthLongitude := normalizeRA(HSunTrueLoNWithInstance(tt, -1, inst)+180) * math.Pi / 180
|
||||
earthDistance := EarthAwayNWithInstance(tt, -1, inst)
|
||||
starX -= earthDistance * math.Cos(earthLongitude)
|
||||
starY -= earthDistance * math.Sin(earthLongitude)
|
||||
|
||||
@@ -580,33 +586,41 @@ func starOccultationLongitudeDistance(tt float64, star StarCoordinate, observer
|
||||
return math.Abs(signedAngleDifference(moonLongitude, starLongitude))
|
||||
}
|
||||
|
||||
func starMoonSeparationArcsec(tt float64, star StarCoordinate, observer Observer) float64 {
|
||||
position := starMoonPositionAt(tt, star, observer)
|
||||
func starMoonSeparationArcsec(tt float64, star StarCoordinate, observer Observer, instances ...*Instance) float64 {
|
||||
inst := instanceValue(instances)
|
||||
|
||||
position := starMoonPositionAt(tt, star, observer, inst)
|
||||
if !position.valid {
|
||||
return math.Inf(1)
|
||||
}
|
||||
return angularSeparationDegrees(position.moonRA, position.moonDec, position.starRA, position.starDec) * 3600
|
||||
}
|
||||
|
||||
func starOccultationLatitudePass(tt float64, star StarCoordinate, observer Observer, safetyMarginArcsec float64) bool {
|
||||
starRA, starDec := starApparentRaDec(tt, star, observer)
|
||||
func starOccultationLatitudePass(tt float64, star StarCoordinate, observer Observer, safetyMarginArcsec float64, instances ...*Instance) bool {
|
||||
inst := instanceValue(instances)
|
||||
|
||||
starRA, starDec := starApparentRaDec(tt, star, observer, inst)
|
||||
_, starLatitude := RaDecToLoBo(tt, starRA, starDec)
|
||||
moonLatitude := HMoonTrueBoN(tt, 8)
|
||||
moonRadius := moonTopocentricSemidiameterN(tt, observer, -1)
|
||||
moonLatitude := HMoonTrueBoNWithInstance(tt, 8, inst)
|
||||
moonRadius := moonTopocentricSemidiameterN(tt, observer, -1, inst)
|
||||
limit := moonRadius + starOccultationLatitudeMarginAS + safetyMarginArcsec
|
||||
return math.Abs(starLatitude-moonLatitude)*3600 <= limit
|
||||
}
|
||||
|
||||
func starOccultationLatitudePassGeocentric(tt float64, star StarCoordinate, safetyMarginArcsec float64) bool {
|
||||
starRA, starDec := starApparentRaDecGeocentric(tt, star)
|
||||
func starOccultationLatitudePassGeocentric(tt float64, star StarCoordinate, safetyMarginArcsec float64, instances ...*Instance) bool {
|
||||
inst := instanceValue(instances)
|
||||
|
||||
starRA, starDec := starApparentRaDecGeocentric(tt, star, inst)
|
||||
_, starLatitude := RaDecToLoBo(tt, starRA, starDec)
|
||||
moonLatitude := HMoonTrueBoN(tt, 8)
|
||||
limit := MoonSemidiameter(tt) + starOccultationLatitudeMarginAS + safetyMarginArcsec
|
||||
moonLatitude := HMoonTrueBoNWithInstance(tt, 8, inst)
|
||||
limit := MoonSemidiameterWithInstance(tt, inst) + starOccultationLatitudeMarginAS + safetyMarginArcsec
|
||||
return math.Abs(starLatitude-moonLatitude)*3600 <= limit
|
||||
}
|
||||
|
||||
func starOccultationContact(greatestTT, boundaryTT float64, direction int, star StarCoordinate, observer Observer) (float64, bool) {
|
||||
valueAtGreatest := starMoonSeparationArcsec(greatestTT, star, observer) - moonTopocentricSemidiameterN(greatestTT, observer, -1)
|
||||
func starOccultationContact(greatestTT, boundaryTT float64, direction int, star StarCoordinate, observer Observer, instances ...*Instance) (float64, bool) {
|
||||
inst := instanceValue(instances)
|
||||
|
||||
valueAtGreatest := starMoonSeparationArcsec(greatestTT, star, observer, inst) - moonTopocentricSemidiameterN(greatestTT, observer, -1, inst)
|
||||
if !finite(valueAtGreatest) || valueAtGreatest > 0 {
|
||||
return math.NaN(), false
|
||||
}
|
||||
@@ -621,9 +635,9 @@ func starOccultationContact(greatestTT, boundaryTT float64, direction int, star
|
||||
if direction > 0 && nextTT > boundaryTT {
|
||||
nextTT = boundaryTT
|
||||
}
|
||||
nextValue := starMoonSeparationArcsec(nextTT, star, observer) - moonTopocentricSemidiameterN(nextTT, observer, -1)
|
||||
nextValue := starMoonSeparationArcsec(nextTT, star, observer, inst) - moonTopocentricSemidiameterN(nextTT, observer, -1, inst)
|
||||
if finite(nextValue) && nextValue >= 0 {
|
||||
return starOccultationRoot(currentTT, nextTT, currentValue, nextValue, star, observer)
|
||||
return starOccultationRoot(currentTT, nextTT, currentValue, nextValue, star, observer, inst)
|
||||
}
|
||||
if nextTT == boundaryTT {
|
||||
return math.NaN(), false
|
||||
@@ -634,7 +648,9 @@ func starOccultationContact(greatestTT, boundaryTT float64, direction int, star
|
||||
return math.NaN(), false
|
||||
}
|
||||
|
||||
func starOccultationRoot(leftTT, rightTT, leftValue, rightValue float64, star StarCoordinate, observer Observer) (float64, bool) {
|
||||
func starOccultationRoot(leftTT, rightTT, leftValue, rightValue float64, star StarCoordinate, observer Observer, instances ...*Instance) (float64, bool) {
|
||||
inst := instanceValue(instances)
|
||||
|
||||
if !finite(leftValue) || !finite(rightValue) || leftValue*rightValue > 0 {
|
||||
return math.NaN(), false
|
||||
}
|
||||
@@ -646,7 +662,7 @@ func starOccultationRoot(leftTT, rightTT, leftValue, rightValue float64, star St
|
||||
}
|
||||
for i := 0; i < 64 && math.Abs(rightTT-leftTT) > starOccultationRootToleranceDays; i++ {
|
||||
midTT := (leftTT + rightTT) / 2
|
||||
midValue := starMoonSeparationArcsec(midTT, star, observer) - moonTopocentricSemidiameterN(midTT, observer, -1)
|
||||
midValue := starMoonSeparationArcsec(midTT, star, observer, inst) - moonTopocentricSemidiameterN(midTT, observer, -1, inst)
|
||||
if !finite(midValue) {
|
||||
return math.NaN(), false
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user