b612
ccf5880269
- 基于平均下合周期与节点相位预筛候选，减少无效星历计算；跳过无法求解的单个会合周期，避免有限覆盖星历导致搜索提前终止 - 引入影轴 γ、半影半径及地球尺度几何判定，结合站心可见性识别地心无接触、仅部分地区可见的掠凌 - 添加金星 243 年、水星 46 年周期族编号，并明确编号适用范围及未分配时的零值语义 - 为 SVG、GeoJSON 和 KML 增加站心部分凌日可见区，适配接触等时线、几何元数据、图层样式及取景；为地心无接触凌日事件增加正射图，按可见区球面面积加权居中
116 lines
4.8 KiB
Go
116 lines
4.8 KiB
Go
package mercury
|
|
|
|
import (
|
|
"time"
|
|
|
|
"b612.me/astro/basic"
|
|
)
|
|
|
|
// TransitInfo 全球水星凌日与地心接触 / global Mercury transit and geocentric contacts.
|
|
//
|
|
// Start、Greatest、End、InternalStart、InternalEnd 都保持调用者输入的时区。
|
|
// 地心接触不存在时对应时刻为零值；WindowStart、WindowEnd 只是站心求解窗口。
|
|
// Start, Greatest, End, InternalStart, and InternalEnd preserve the caller's timezone.
|
|
// Absent geocentric contacts are zero; WindowStart and WindowEnd are only a local search window.
|
|
type TransitInfo struct {
|
|
Valid bool
|
|
|
|
Start time.Time
|
|
InternalStart time.Time
|
|
Greatest time.Time
|
|
InternalEnd time.Time
|
|
End time.Time
|
|
|
|
Duration time.Duration
|
|
InternalDuration time.Duration
|
|
|
|
MinimumSeparationArcsec float64
|
|
SunSemidiameterArcsec float64
|
|
PlanetSemidiameterArcsec float64
|
|
|
|
HasInternal bool
|
|
HasExternal bool
|
|
WindowStart time.Time
|
|
WindowEnd time.Time
|
|
Gamma float64
|
|
PenumbralRadius float64
|
|
Series basic.PlanetTransitSeries
|
|
}
|
|
|
|
// NextTransit 下一次全球水星凌日 / next global Mercury transit.
|
|
func (module *Mercury) NextTransit(date time.Time) TransitInfo {
|
|
return transitInfoFromBasic(basic.NextMercuryTransitWithInstance(basic.Date2JD(date.UTC()), module.inst), date.Location())
|
|
}
|
|
|
|
// LastTransit 上一次全球水星凌日 / previous global Mercury transit.
|
|
func (module *Mercury) LastTransit(date time.Time) TransitInfo {
|
|
return transitInfoFromBasic(basic.LastMercuryTransitWithInstance(basic.Date2JD(date.UTC()), module.inst), date.Location())
|
|
}
|
|
|
|
// ClosestTransit 最近一次全球水星凌日 / closest global Mercury transit.
|
|
func (module *Mercury) ClosestTransit(date time.Time) TransitInfo {
|
|
return transitInfoFromBasic(basic.ClosestMercuryTransitWithInstance(basic.Date2JD(date.UTC()), module.inst), date.Location())
|
|
}
|
|
|
|
func transitInfoFromBasic(result basic.PlanetTransitResult, loc *time.Location) TransitInfo {
|
|
if !result.Valid {
|
|
return TransitInfo{}
|
|
}
|
|
greatest := basic.JD2DateByZone(result.Greatest, loc, false)
|
|
info := TransitInfo{
|
|
Valid: true,
|
|
Greatest: greatest,
|
|
MinimumSeparationArcsec: result.MinimumSeparationArcsec,
|
|
SunSemidiameterArcsec: result.SunSemidiameterArcsec,
|
|
PlanetSemidiameterArcsec: result.PlanetSemidiameterArcsec,
|
|
HasInternal: result.HasInternal,
|
|
HasExternal: result.HasExternal,
|
|
WindowStart: basic.JD2DateByZone(result.WindowStart, loc, false),
|
|
WindowEnd: basic.JD2DateByZone(result.WindowEnd, loc, false),
|
|
Gamma: result.Gamma,
|
|
PenumbralRadius: result.PenumbralRadius,
|
|
Series: result.Series,
|
|
}
|
|
if result.HasExternal {
|
|
info.Start = basic.JD2DateByZone(result.ExternalIngress, loc, false)
|
|
info.End = basic.JD2DateByZone(result.ExternalEgress, loc, false)
|
|
info.Duration = info.End.Sub(info.Start)
|
|
}
|
|
if result.HasInternal {
|
|
info.InternalStart = basic.JD2DateByZone(result.InternalIngress, loc, false)
|
|
info.InternalEnd = basic.JD2DateByZone(result.InternalEgress, loc, false)
|
|
info.InternalDuration = info.InternalEnd.Sub(info.InternalStart)
|
|
}
|
|
return info
|
|
}
|
|
|
|
// LocalTransitInfo 站心水星凌日信息 / topocentric Mercury transit information.
|
|
//
|
|
// 时刻保持调用者传入的 TransitInfo 的时区；太阳高度为几何中心高度，不含折射。
|
|
// Times keep the timezone of the supplied TransitInfo; Sun altitudes are geometric centre altitudes without refraction.
|
|
type LocalTransitInfo = basic.PlanetTransitLocalInfo
|
|
|
|
// LocalTransitContact 站心凌日接触 / topocentric transit contact.
|
|
type LocalTransitContact = basic.PlanetTransitLocalContactInfo
|
|
|
|
// LocalTransit 凌日 transit 在观测地的站心接触与凌甚 / topocentric contacts of transit seen from the site.
|
|
//
|
|
// lon、lat 为度，东经、北纬为正；height 为海拔米。
|
|
// lon and lat are in degrees, east and north positive; height is in meters.
|
|
func (module *Mercury) LocalTransit(transit TransitInfo, lon, lat, height float64) LocalTransitInfo {
|
|
if !transit.Valid {
|
|
return LocalTransitInfo{}
|
|
}
|
|
local := basic.PlanetTransitLocalWithInstance(transitResultFromInfo(transit), basic.Observer{Longitude: lon, Latitude: lat, Height: height}, module.inst)
|
|
return basic.PlanetTransitLocalInfoFromResult(local, transit.Greatest.Location())
|
|
}
|
|
|
|
// transitResultFromInfo 按一触、四触是否为零选择地心接触或求解窗口还原 basic 结果。
|
|
func transitResultFromInfo(transit TransitInfo) basic.PlanetTransitResult {
|
|
if transit.Start.IsZero() && transit.End.IsZero() {
|
|
return basic.PlanetTransitResultFromWindow(1, transit.WindowStart, transit.Greatest, transit.WindowEnd)
|
|
}
|
|
return basic.PlanetTransitResultFromTimes(1,
|
|
transit.Start, transit.InternalStart, transit.Greatest, transit.InternalEnd, transit.End)
|
|
}
|