|
|
package basic
|
|
|
|
|
|
import (
|
|
|
"math"
|
|
|
|
|
|
"b612.me/astro/planet"
|
|
|
. "b612.me/astro/tools"
|
|
|
)
|
|
|
|
|
|
func VenusL(JD float64) float64 {
|
|
|
return planet.WherePlanet(2, 0, JD)
|
|
|
}
|
|
|
|
|
|
func VenusB(JD float64) float64 {
|
|
|
return planet.WherePlanet(2, 1, JD)
|
|
|
}
|
|
|
func VenusR(JD float64) float64 {
|
|
|
return planet.WherePlanet(2, 2, JD)
|
|
|
}
|
|
|
func AVenusX(JD float64) float64 {
|
|
|
l := VenusL(JD)
|
|
|
b := VenusB(JD)
|
|
|
r := VenusR(JD)
|
|
|
el := planet.WherePlanet(-1, 0, JD)
|
|
|
eb := planet.WherePlanet(-1, 1, JD)
|
|
|
er := planet.WherePlanet(-1, 2, JD)
|
|
|
x := r*Cos(b)*Cos(l) - er*Cos(eb)*Cos(el)
|
|
|
return x
|
|
|
}
|
|
|
|
|
|
func AVenusY(JD float64) float64 {
|
|
|
|
|
|
l := VenusL(JD)
|
|
|
b := VenusB(JD)
|
|
|
r := VenusR(JD)
|
|
|
el := planet.WherePlanet(-1, 0, JD)
|
|
|
eb := planet.WherePlanet(-1, 1, JD)
|
|
|
er := planet.WherePlanet(-1, 2, JD)
|
|
|
y := r*Cos(b)*Sin(l) - er*Cos(eb)*Sin(el)
|
|
|
return y
|
|
|
}
|
|
|
func AVenusZ(JD float64) float64 {
|
|
|
//l := VenusL(JD)
|
|
|
b := VenusB(JD)
|
|
|
r := VenusR(JD)
|
|
|
// el := planet.WherePlanet(-1, 0, JD)
|
|
|
eb := planet.WherePlanet(-1, 1, JD)
|
|
|
er := planet.WherePlanet(-1, 2, JD)
|
|
|
z := r*Sin(b) - er*Sin(eb)
|
|
|
return z
|
|
|
}
|
|
|
|
|
|
func AVenusXYZ(JD float64) (float64, float64, float64) {
|
|
|
l := VenusL(JD)
|
|
|
b := VenusB(JD)
|
|
|
r := VenusR(JD)
|
|
|
el := planet.WherePlanet(-1, 0, JD)
|
|
|
eb := planet.WherePlanet(-1, 1, JD)
|
|
|
er := planet.WherePlanet(-1, 2, JD)
|
|
|
x := r*Cos(b)*Cos(l) - er*Cos(eb)*Cos(el)
|
|
|
y := r*Cos(b)*Sin(l) - er*Cos(eb)*Sin(el)
|
|
|
z := r*Sin(b) - er*Sin(eb)
|
|
|
return x, y, z
|
|
|
}
|
|
|
|
|
|
func VenusApparentRa(JD float64) float64 {
|
|
|
lo, bo := VenusApparentLoBo(JD)
|
|
|
sita := Sita(JD)
|
|
|
ra := math.Atan2((Sin(lo)*Cos(sita) - Tan(bo)*Sin(sita)), Cos(lo))
|
|
|
ra = ra * 180 / math.Pi
|
|
|
return Limit360(ra)
|
|
|
}
|
|
|
func VenusApparentDec(JD float64) float64 {
|
|
|
lo, bo := VenusApparentLoBo(JD)
|
|
|
sita := Sita(JD)
|
|
|
dec := ArcSin(Sin(bo)*Cos(sita) + Cos(bo)*Sin(sita)*Sin(lo))
|
|
|
return dec
|
|
|
}
|
|
|
|
|
|
func VenusApparentRaDec(JD float64) (float64, float64) {
|
|
|
lo, bo := VenusApparentLoBo(JD)
|
|
|
sita := Sita(JD)
|
|
|
ra := math.Atan2((Sin(lo)*Cos(sita) - Tan(bo)*Sin(sita)), Cos(lo))
|
|
|
ra = ra * 180 / math.Pi
|
|
|
dec := ArcSin(Sin(bo)*Cos(sita) + Cos(bo)*Sin(sita)*Sin(lo))
|
|
|
return Limit360(ra), dec
|
|
|
}
|
|
|
|
|
|
func EarthVenusAway(JD float64) float64 {
|
|
|
x, y, z := AVenusXYZ(JD)
|
|
|
to := math.Sqrt(x*x + y*y + z*z)
|
|
|
return to
|
|
|
}
|
|
|
|
|
|
func VenusApparentLo(JD float64) float64 {
|
|
|
x, y, z := AVenusXYZ(JD)
|
|
|
to := 0.0057755183 * math.Sqrt(x*x+y*y+z*z)
|
|
|
x, y, z = AVenusXYZ(JD - to)
|
|
|
lo := math.Atan2(y, x)
|
|
|
bo := math.Atan2(z, math.Sqrt(x*x+y*y))
|
|
|
lo = lo * 180 / math.Pi
|
|
|
bo = bo * 180 / math.Pi
|
|
|
lo = Limit360(lo)
|
|
|
//lo-=GXCLo(lo,bo,JD)/3600;
|
|
|
//bo+=GXCBo(lo,bo,JD);
|
|
|
lo += HJZD(JD)
|
|
|
return lo
|
|
|
}
|
|
|
|
|
|
func VenusApparentBo(JD float64) float64 {
|
|
|
x, y, z := AVenusXYZ(JD)
|
|
|
to := 0.0057755183 * math.Sqrt(x*x+y*y+z*z)
|
|
|
x, y, z = AVenusXYZ(JD - to)
|
|
|
//lo := math.Atan2(y, x)
|
|
|
bo := math.Atan2(z, math.Sqrt(x*x+y*y))
|
|
|
//lo = lo * 180 / math.Pi
|
|
|
bo = bo * 180 / math.Pi
|
|
|
//lo+=GXCLo(lo,bo,JD);
|
|
|
//bo+=GXCBo(lo,bo,JD)/3600;
|
|
|
//lo+=HJZD(JD);
|
|
|
return bo
|
|
|
}
|
|
|
|
|
|
func VenusApparentLoBo(JD float64) (float64, float64) {
|
|
|
x, y, z := AVenusXYZ(JD)
|
|
|
to := 0.0057755183 * math.Sqrt(x*x+y*y+z*z)
|
|
|
x, y, z = AVenusXYZ(JD - to)
|
|
|
lo := math.Atan2(y, x)
|
|
|
bo := math.Atan2(z, math.Sqrt(x*x+y*y))
|
|
|
lo = lo * 180 / math.Pi
|
|
|
bo = bo * 180 / math.Pi
|
|
|
lo = Limit360(lo)
|
|
|
//lo-=GXCLo(lo,bo,JD)/3600;
|
|
|
//bo+=GXCBo(lo,bo,JD);
|
|
|
lo += HJZD(JD)
|
|
|
return lo, bo
|
|
|
}
|
|
|
|
|
|
func VenusMag(JD float64) float64 {
|
|
|
AwaySun := VenusR(JD)
|
|
|
AwayEarth := EarthVenusAway(JD)
|
|
|
Away := planet.WherePlanet(-1, 2, JD)
|
|
|
i := (AwaySun*AwaySun + AwayEarth*AwayEarth - Away*Away) / (2 * AwaySun * AwayEarth)
|
|
|
i = ArcCos(i)
|
|
|
Mag := -4.40 + 5*math.Log10(AwaySun*AwayEarth) + 0.0009*i + 0.000239*i*i - 0.00000065*i*i*i
|
|
|
return FloatRound(Mag, 2)
|
|
|
}
|
|
|
|
|
|
func VenusHeight(jde, lon, lat, timezone float64) float64 {
|
|
|
// 转换为世界时
|
|
|
utcJde := jde - timezone/24.0
|
|
|
// 计算视恒星时
|
|
|
ra, dec := VenusApparentRaDec(TD2UT(utcJde, true))
|
|
|
st := Limit360(ApparentSiderealTime(utcJde)*15 + lon)
|
|
|
// 计算时角
|
|
|
H := Limit360(st - ra)
|
|
|
// 高度角、时角与天球座标三角转换公式
|
|
|
// sin(h)=sin(lat)*sin(dec)+cos(dec)*cos(lat)*cos(H)
|
|
|
sinHeight := Sin(lat)*Sin(dec) + Cos(dec)*Cos(lat)*Cos(H)
|
|
|
return ArcSin(sinHeight)
|
|
|
}
|
|
|
|
|
|
func VenusAzimuth(jde, lon, lat, timezone float64) float64 {
|
|
|
// 转换为世界时
|
|
|
utcJde := jde - timezone/24.0
|
|
|
// 计算视恒星时
|
|
|
ra, dec := VenusApparentRaDec(TD2UT(utcJde, true))
|
|
|
st := Limit360(ApparentSiderealTime(utcJde)*15 + lon)
|
|
|
// 计算时角
|
|
|
H := Limit360(st - ra)
|
|
|
// 三角转换公式
|
|
|
tanAzimuth := Sin(H) / (Cos(H)*Sin(lat) - Tan(dec)*Cos(lat))
|
|
|
Azimuth := ArcTan(tanAzimuth)
|
|
|
if Azimuth < 0 {
|
|
|
if H/15 < 12 {
|
|
|
return Azimuth + 360
|
|
|
}
|
|
|
return Azimuth + 180
|
|
|
}
|
|
|
if H/15 < 12 {
|
|
|
return Azimuth + 180
|
|
|
}
|
|
|
return Azimuth
|
|
|
}
|
|
|
|
|
|
func VenusHourAngle(JD, Lon, TZ float64) float64 {
|
|
|
startime := Limit360(ApparentSiderealTime(JD-TZ/24)*15 + Lon)
|
|
|
timeangle := startime - VenusApparentRa(TD2UT(JD-TZ/24.0, true))
|
|
|
if timeangle < 0 {
|
|
|
timeangle += 360
|
|
|
}
|
|
|
return timeangle
|
|
|
}
|
|
|
|
|
|
func VenusCulminationTime(jde, lon, timezone float64) float64 {
|
|
|
//jde 世界时，非力学时，当地时区 0时，无需转换力学时
|
|
|
//ra,dec 瞬时天球座标，非J2000等时间天球坐标
|
|
|
jde = math.Floor(jde) + 0.5
|
|
|
JD1 := jde + Limit360(360-VenusHourAngle(jde, lon, timezone))/15.0/24.0*0.99726851851851851851
|
|
|
limitHA := func(jde, lon, timezone float64) float64 {
|
|
|
ha := VenusHourAngle(jde, lon, timezone)
|
|
|
if ha < 180 {
|
|
|
ha += 360
|
|
|
}
|
|
|
return ha
|
|
|
}
|
|
|
for {
|
|
|
JD0 := JD1
|
|
|
stDegree := limitHA(JD0, lon, timezone) - 360
|
|
|
stDegreep := (limitHA(JD0+0.000005, lon, timezone) - limitHA(JD0-0.000005, lon, timezone)) / 0.00001
|
|
|
JD1 = JD0 - stDegree/stDegreep
|
|
|
if math.Abs(JD1-JD0) <= 0.00001 {
|
|
|
break
|
|
|
}
|
|
|
}
|
|
|
return JD1
|
|
|
}
|
|
|
|
|
|
func VenusRiseTime(JD, Lon, Lat, TZ, ZS, HEI float64) float64 {
|
|
|
return venusRiseDown(JD, Lon, Lat, TZ, ZS, HEI, true)
|
|
|
}
|
|
|
|
|
|
func VenusDownTime(JD, Lon, Lat, TZ, ZS, HEI float64) float64 {
|
|
|
return venusRiseDown(JD, Lon, Lat, TZ, ZS, HEI, false)
|
|
|
}
|
|
|
|
|
|
func venusRiseDown(JD, Lon, Lat, TZ, ZS, HEI float64, isRise bool) float64 {
|
|
|
var An float64
|
|
|
JD = math.Floor(JD) + 0.5
|
|
|
ntz := math.Round(Lon / 15)
|
|
|
if ZS != 0 {
|
|
|
An = -0.8333
|
|
|
}
|
|
|
An = An - HeightDegreeByLat(HEI, Lat)
|
|
|
tztime := VenusCulminationTime(JD, Lon, ntz)
|
|
|
if VenusHeight(tztime, Lon, Lat, ntz) < An {
|
|
|
return -2 //极夜
|
|
|
}
|
|
|
if VenusHeight(tztime-0.5, Lon, Lat, ntz) > An {
|
|
|
return -1 //极昼
|
|
|
}
|
|
|
dec := HSunApparentDec(TD2UT(tztime-ntz/24, true))
|
|
|
//(sin(ho)-sin(φ)*sin(δ2))/(cos(φ)*cos(δ2))
|
|
|
tmp := (Sin(An) - Sin(dec)*Sin(Lat)) / (Cos(dec) * Cos(Lat))
|
|
|
var rise float64
|
|
|
if math.Abs(tmp) <= 1 {
|
|
|
rzsc := ArcCos(tmp) / 15
|
|
|
if isRise {
|
|
|
rise = tztime - rzsc/24 - 25.0/24.0/60.0
|
|
|
} else {
|
|
|
rise = tztime + rzsc/24 - 25.0/24.0/60.0
|
|
|
}
|
|
|
} else {
|
|
|
rise = tztime
|
|
|
i := 0
|
|
|
//TODO:使用二分法计算
|
|
|
for VenusHeight(rise, Lon, Lat, ntz) > An {
|
|
|
i++
|
|
|
if isRise {
|
|
|
rise -= 15.0 / 60.0 / 24.0
|
|
|
} else {
|
|
|
rise += 15.0 / 60.0 / 24.0
|
|
|
}
|
|
|
if i > 48 {
|
|
|
break
|
|
|
}
|
|
|
}
|
|
|
}
|
|
|
JD1 := rise
|
|
|
for {
|
|
|
JD0 := JD1
|
|
|
stDegree := VenusHeight(JD0, Lon, Lat, ntz) - An
|
|
|
stDegreep := (VenusHeight(JD0+0.000005, Lon, Lat, ntz) - VenusHeight(JD0-0.000005, Lon, Lat, ntz)) / 0.00001
|
|
|
JD1 = JD0 - stDegree/stDegreep
|
|
|
if math.Abs(JD1-JD0) <= 0.00001 {
|
|
|
break
|
|
|
}
|
|
|
}
|
|
|
return JD1 - ntz/24 + TZ/24
|
|
|
}
|
|
|
|
|
|
// Pos
|
|
|
|
|
|
const VENUS_S_PERIOD = 1 / ((1 / 224.701) - (1 / 365.256363004))
|
|
|
|
|
|
func venusConjunction(jde float64, next uint8) float64 {
|
|
|
//0=last 1=next
|
|
|
decSub := func(jde float64) float64 {
|
|
|
sub := Limit360(VenusApparentLo(jde) - HSunApparentLo(jde))
|
|
|
if sub > 180 {
|
|
|
sub -= 360
|
|
|
}
|
|
|
if sub < -180 {
|
|
|
sub += 360
|
|
|
}
|
|
|
return sub
|
|
|
}
|
|
|
nowSub := decSub(jde)
|
|
|
pos := math.Abs(decSub(jde+1/86400.0)) - math.Abs(nowSub)
|
|
|
if pos >= 0 && next == 1 && nowSub > 0 {
|
|
|
jde += VENUS_S_PERIOD/8.0 + 2
|
|
|
}
|
|
|
if pos >= 0 && next == 1 && nowSub < 0 {
|
|
|
jde += VENUS_S_PERIOD/6.0 + 2
|
|
|
}
|
|
|
if pos <= 0 && next == 0 && nowSub < 0 {
|
|
|
jde -= VENUS_S_PERIOD/8.0 + 2
|
|
|
}
|
|
|
if pos <= 0 && next == 0 && nowSub > 0 {
|
|
|
jde -= VENUS_S_PERIOD/6.0 + 2
|
|
|
}
|
|
|
for {
|
|
|
nowSub := decSub(jde)
|
|
|
pos := math.Abs(decSub(jde+1/86400.0)) - math.Abs(nowSub)
|
|
|
if math.Abs(nowSub) > 24 || (pos > 0 && next == 1) || (pos < 0 && next == 0) {
|
|
|
if next == 1 {
|
|
|
jde += 8
|
|
|
} else {
|
|
|
jde -= 8
|
|
|
}
|
|
|
continue
|
|
|
}
|
|
|
break
|
|
|
}
|
|
|
JD1 := jde
|
|
|
for {
|
|
|
JD0 := JD1
|
|
|
stDegree := decSub(JD0)
|
|
|
stDegreep := (decSub(JD0+0.000005) - decSub(JD0-0.000005)) / 0.00001
|
|
|
JD1 = JD0 - stDegree/stDegreep
|
|
|
if math.Abs(JD1-JD0) <= 0.00001 {
|
|
|
break
|
|
|
}
|
|
|
}
|
|
|
return TD2UT(JD1, false)
|
|
|
}
|
|
|
|
|
|
func LastVenusConjunction(jde float64) float64 {
|
|
|
return venusConjunction(jde, 0)
|
|
|
}
|
|
|
|
|
|
func NextVenusConjunction(jde float64) float64 {
|
|
|
return venusConjunction(jde, 1)
|
|
|
}
|
|
|
|
|
|
func NextVenusInferiorConjunction(jde float64) float64 {
|
|
|
date := NextVenusConjunction(jde)
|
|
|
if EarthVenusAway(date) > EarthAway(date) {
|
|
|
return NextVenusConjunction(date + 2)
|
|
|
}
|
|
|
return date
|
|
|
}
|
|
|
|
|
|
func NextVenusSuperiorConjunction(jde float64) float64 {
|
|
|
date := NextVenusConjunction(jde)
|
|
|
if EarthVenusAway(date) < EarthAway(date) {
|
|
|
return NextVenusConjunction(date + 2)
|
|
|
}
|
|
|
return date
|
|
|
}
|
|
|
|
|
|
func LastVenusInferiorConjunction(jde float64) float64 {
|
|
|
date := LastVenusConjunction(jde)
|
|
|
if EarthVenusAway(date) > EarthAway(date) {
|
|
|
return LastVenusConjunction(date - 2)
|
|
|
}
|
|
|
return date
|
|
|
}
|
|
|
|
|
|
func LastVenusSuperiorConjunction(jde float64) float64 {
|
|
|
date := LastVenusConjunction(jde)
|
|
|
if EarthVenusAway(date) < EarthAway(date) {
|
|
|
return LastVenusConjunction(date - 2)
|
|
|
}
|
|
|
return date
|
|
|
}
|
|
|
|
|
|
func venusRetrograde(jde float64) float64 {
|
|
|
//0=last 1=next
|
|
|
decSunSub := func(jde float64) float64 {
|
|
|
sub := Limit360(VenusApparentRa(jde) - SunApparentRa(jde))
|
|
|
if sub > 180 {
|
|
|
sub -= 360
|
|
|
}
|
|
|
if sub < -180 {
|
|
|
sub += 360
|
|
|
}
|
|
|
return sub
|
|
|
}
|
|
|
decSub := func(jde float64, val float64) float64 {
|
|
|
sub := VenusApparentRa(jde+val) - VenusApparentRa(jde-val)
|
|
|
if sub > 180 {
|
|
|
sub -= 360
|
|
|
}
|
|
|
if sub < -180 {
|
|
|
sub += 360
|
|
|
}
|
|
|
return sub / (2 * val)
|
|
|
}
|
|
|
lastHe := LastVenusConjunction(jde)
|
|
|
nextHe := NextVenusConjunction(jde)
|
|
|
nowSub := decSunSub(jde)
|
|
|
if nowSub > 0 {
|
|
|
jde = lastHe + ((nextHe - lastHe) / 5.0 * 3.5)
|
|
|
} else {
|
|
|
jde = lastHe + 10
|
|
|
}
|
|
|
for {
|
|
|
nowSub := decSub(jde, 1.0/86400.0)
|
|
|
if math.Abs(nowSub) > 0.5 {
|
|
|
jde += 5
|
|
|
continue
|
|
|
}
|
|
|
break
|
|
|
}
|
|
|
JD1 := jde
|
|
|
for {
|
|
|
JD0 := JD1
|
|
|
stDegree := decSub(JD0, 0.5/86400.0)
|
|
|
stDegreep := (decSub(JD0+10.0/86400.0, 0.5/86400.0) - decSub(JD0-10.0/86400.0, 0.5/86400.0)) / (20.0 / 86400.0)
|
|
|
JD1 = JD0 - stDegree/stDegreep
|
|
|
if math.Abs(JD1-JD0) <= 20.0/86400.0 {
|
|
|
break
|
|
|
}
|
|
|
}
|
|
|
JD1 = JD1 - 10.0/86400.0
|
|
|
min := JD1
|
|
|
minRa := 100.0
|
|
|
for i := 0.0; i < 40.0; i++ {
|
|
|
tmp := decSub(JD1+i*0.5/86400.0, 0.5/86400.0)
|
|
|
if math.Abs(tmp) < math.Abs(minRa) {
|
|
|
minRa = tmp
|
|
|
min = JD1 + i*0.5/86400.0
|
|
|
}
|
|
|
}
|
|
|
//fmt.Println((min - lastHe) / (nextHe - lastHe))
|
|
|
return TD2UT(min, false)
|
|
|
}
|
|
|
|
|
|
func NextVenusRetrograde(jde float64) float64 {
|
|
|
date := venusRetrograde(jde)
|
|
|
if date < jde {
|
|
|
nextHe := NextVenusConjunction(jde)
|
|
|
return venusRetrograde(nextHe + 2)
|
|
|
}
|
|
|
return date
|
|
|
}
|
|
|
|
|
|
func LastVenusRetrograde(jde float64) float64 {
|
|
|
lastHe := LastVenusConjunction(jde)
|
|
|
date := venusRetrograde(lastHe + 2)
|
|
|
if date > jde {
|
|
|
lastLastHe := LastVenusConjunction(lastHe - 2)
|
|
|
return venusRetrograde(lastLastHe + 2)
|
|
|
}
|
|
|
return date
|
|
|
}
|
|
|
|
|
|
func NextVenusProgradeToRetrograde(jde float64) float64 {
|
|
|
date := NextVenusRetrograde(jde)
|
|
|
sub := Limit360(VenusApparentRa(date) - SunApparentRa(date))
|
|
|
if sub > 180 {
|
|
|
return NextVenusRetrograde(date + VENUS_S_PERIOD/2)
|
|
|
}
|
|
|
return date
|
|
|
}
|
|
|
|
|
|
func NextVenusRetrogradeToPrograde(jde float64) float64 {
|
|
|
date := NextVenusRetrograde(jde)
|
|
|
sub := Limit360(VenusApparentRa(date) - SunApparentRa(date))
|
|
|
if sub < 180 {
|
|
|
return NextVenusRetrograde(date + 12)
|
|
|
}
|
|
|
return date
|
|
|
}
|
|
|
|
|
|
func LastVenusProgradeToRetrograde(jde float64) float64 {
|
|
|
date := LastVenusRetrograde(jde)
|
|
|
sub := Limit360(VenusApparentRa(date) - SunApparentRa(date))
|
|
|
if sub > 180 {
|
|
|
return LastVenusRetrograde(date - 12)
|
|
|
}
|
|
|
return date
|
|
|
}
|
|
|
|
|
|
func LastVenusRetrogradeToPrograde(jde float64) float64 {
|
|
|
date := LastVenusRetrograde(jde)
|
|
|
sub := Limit360(VenusApparentRa(date) - SunApparentRa(date))
|
|
|
if sub < 180 {
|
|
|
return LastVenusRetrograde(date - VENUS_S_PERIOD/2)
|
|
|
}
|
|
|
return date
|
|
|
}
|
|
|
|
|
|
func VenusSunElongation(jde float64) float64 {
|
|
|
lo1, bo1 := VenusApparentLoBo(jde)
|
|
|
lo2 := SunApparentLo(jde)
|
|
|
bo2 := HSunTrueBo(jde)
|
|
|
return StarAngularSeparation(lo1, bo1, lo2, bo2)
|
|
|
}
|
|
|
func venusGreatestElongation(jde float64) float64 {
|
|
|
decSunSub := func(jde float64) float64 {
|
|
|
sub := Limit360(VenusApparentRa(jde) - SunApparentRa(jde))
|
|
|
if sub > 180 {
|
|
|
sub -= 360
|
|
|
}
|
|
|
if sub < -180 {
|
|
|
sub += 360
|
|
|
}
|
|
|
return sub
|
|
|
}
|
|
|
decSub := func(jde float64, val float64) float64 {
|
|
|
sub := VenusSunElongation(jde+val) - VenusSunElongation(jde-val)
|
|
|
if sub > 180 {
|
|
|
sub -= 360
|
|
|
}
|
|
|
if sub < -180 {
|
|
|
sub += 360
|
|
|
}
|
|
|
return sub / (2 * val)
|
|
|
}
|
|
|
lastHe := LastVenusConjunction(jde)
|
|
|
nextHe := NextVenusConjunction(jde)
|
|
|
nowSub := decSunSub(jde)
|
|
|
if nowSub > 0 {
|
|
|
jde = lastHe + ((nextHe - lastHe) / 5.0 * 2.5)
|
|
|
} else {
|
|
|
jde = lastHe + ((nextHe - lastHe) / 5.0)
|
|
|
}
|
|
|
for {
|
|
|
nowSub := decSub(jde, 1.0/86400.0)
|
|
|
if math.Abs(nowSub) > 0.15 {
|
|
|
jde += 5
|
|
|
continue
|
|
|
}
|
|
|
break
|
|
|
}
|
|
|
JD1 := jde
|
|
|
for {
|
|
|
JD0 := JD1
|
|
|
stDegree := decSub(JD0, 2.0/86400.0)
|
|
|
stDegreep := (decSub(JD0+15.0/86400.0, 2.0/86400.0) - decSub(JD0-15.0/86400.0, 2.0/86400.0)) / (30.0 / 86400.0)
|
|
|
JD1 = JD0 - stDegree/stDegreep
|
|
|
if math.Abs(JD1-JD0) <= 30.0/86400.0 {
|
|
|
break
|
|
|
}
|
|
|
}
|
|
|
JD1 = JD1 - 15.0/86400.0
|
|
|
min := JD1
|
|
|
minRa := 100.0
|
|
|
for i := 0.0; i < 60.0; i++ {
|
|
|
tmp := decSub(JD1+i*0.5/86400.0, 0.5/86400.0)
|
|
|
if math.Abs(tmp) < math.Abs(minRa) {
|
|
|
minRa = tmp
|
|
|
min = JD1 + i*0.5/86400.0
|
|
|
}
|
|
|
}
|
|
|
//fmt.Println((min - lastHe) / (nextHe - lastHe))
|
|
|
return TD2UT(min, false)
|
|
|
}
|
|
|
|
|
|
func NextVenusGreatestElongation(jde float64) float64 {
|
|
|
date := venusGreatestElongation(jde)
|
|
|
if date < jde {
|
|
|
nextHe := NextVenusConjunction(jde)
|
|
|
return venusGreatestElongation(nextHe + 2)
|
|
|
}
|
|
|
return date
|
|
|
}
|
|
|
|
|
|
func LastVenusGreatestElongation(jde float64) float64 {
|
|
|
lastHe := LastVenusConjunction(jde)
|
|
|
date := venusGreatestElongation(lastHe + 2)
|
|
|
if date > jde {
|
|
|
lastLastHe := LastVenusConjunction(lastHe - 2)
|
|
|
return venusGreatestElongation(lastLastHe + 2)
|
|
|
}
|
|
|
return date
|
|
|
}
|
|
|
|
|
|
func NextVenusGreatestElongationEast(jde float64) float64 {
|
|
|
date := NextVenusGreatestElongation(jde)
|
|
|
sub := Limit360(VenusApparentRa(date) - SunApparentRa(date))
|
|
|
if sub > 180 {
|
|
|
return NextVenusGreatestElongation(date + 1)
|
|
|
}
|
|
|
return date
|
|
|
}
|
|
|
|
|
|
func NextVenusGreatestElongationWest(jde float64) float64 {
|
|
|
date := NextVenusGreatestElongation(jde)
|
|
|
sub := Limit360(VenusApparentRa(date) - SunApparentRa(date))
|
|
|
if sub < 180 {
|
|
|
return NextVenusGreatestElongation(date + 1)
|
|
|
}
|
|
|
return date
|
|
|
}
|
|
|
|
|
|
func LastVenusGreatestElongationEast(jde float64) float64 {
|
|
|
date := LastVenusGreatestElongation(jde)
|
|
|
sub := Limit360(VenusApparentRa(date) - SunApparentRa(date))
|
|
|
if sub > 180 {
|
|
|
return LastVenusGreatestElongation(date - 1)
|
|
|
}
|
|
|
return date
|
|
|
}
|
|
|
|
|
|
func LastVenusGreatestElongationWest(jde float64) float64 {
|
|
|
date := LastVenusGreatestElongation(jde)
|
|
|
sub := Limit360(VenusApparentRa(date) - SunApparentRa(date))
|
|
|
if sub < 180 {
|
|
|
return LastVenusGreatestElongation(date - 1)
|
|
|
}
|
|
|
return date
|
|
|
}
|