Option Explicit
Const pi = 3.1415926535898
Private a, b, c, alpha, e, e2, w, V As Double
Private B1, L1, B2, L2 As Double
Private s As Double
Private A1, A2 As Double
Private Sub getellipseparameter()
a = 6378245
b = 6356752.3142
c = a ^ 2 / b
alpha = (a - b) / a
e = Sqr(a ^ 2 - b ^ 2) / a
e2 = Sqr(a ^ 2 - b ^ 2) / b
End Sub
Private Function computerw()
w = Sqr(1 - e ^ 2 * (Sin(B1) ^ 2))
V = w * (a / b)
End Function
Function Computation(STARTLAT, STARTLONG, ANGLE1, DISTANCE As Double) As String '''''正算
Dim sinu1, cosu1, sinA0, cotq1, sin2q1, cos2q1, cos2A0 As Double
Dim k2, q0, sin2q1q0, cos2q1q0 As Double
Dim q As Double
Dim theta As Double
Dim aa, BB, cc, EE22, AAlpha, BBeta As Double
Dim sinu2, lamuda As Double
Dim e1 As Double
Dim W1 As Double
B1 = STARTLAT
L1 = STARTLONG
A1 = ANGLE1
s = DISTANCE
Call getellipseparameter
If B1 = 0 Then
If A1 = 90 Then
A2 = 270
B2 = 0
L2 = L1 + s / a * 180 / pi
End If
If A1 = 270 Then
A2 = 90
B2 = 0
L2 = L1 - s / a * 180 / pi
End If
Exit Function
End If
B1 = rad(B1)
L1 = rad(L1)
A1 = rad(A1)
Call computerw
e1 = e
W1 = w
sinu1 = Sin(B1) * Sqr(1 - e1 * e1) / W1
cosu1 = Cos(B1) / W1
sinA0 = cosu1 * Sin(A1)
cotq1 = cosu1 * Cos(A1)
sin2q1 = 2 * cotq1 / (cotq1 ^ 2 + 1)
cos2q1 = (cotq1 ^ 2 - 1) / (cotq1 ^ 2 + 1)
cos2A0 = 1 - sinA0 ^ 2
e2 = Sqr(a ^ 2 - b ^ 2) / b
k2 = e2 * e2 * cos2A0
aa = b * (1 + k2 / 4 - 3 * k2 * k2 / 64 + 5 * k2 * k2 * k2 / 256)
BB = b * (k2 / 8 - k2 * k2 / 32 + 15 * k2 * k2 * k2 / 1024)
cc = b * (k2 * k2 / 128 - 3 * k2 * k2 * k2 / 512)
e2 = e1 * e1
AAlpha = (e2 / 2 + e2 * e2 / 8 + e2 * e2 * e2 / 16) - (e2 * e2 / 16 + e2 * e2 * e2 / 16) * cos2A0 + (3 * e2 * e2 * e2 / 128) * cos2A0 * cos2A0
BBeta = (e2 * e2 / 32 + e2 * e2 * e2 / 32) * cos2A0 - (e2 * e2 * e2 / 64) * cos2A0 * cos2A0
q0 = (s - (BB + cc * cos2q1) * sin2q1) / aa
sin2q1q0 = sin2q1 * Cos(2 * q0) + cos2q1 * Sin(2 * q0)
cos2q1q0 = cos2q1 * Cos(2 * q0) - sin2q1 * Sin(2 * q0)
q = q0 + (BB + 5 * cc * cos2q1q0) * sin2q1q0 / aa
'theta = (AAlpha * q + BBeta * (sin2q1q0 - sin2q1)) * sinA0
theta = (AAlpha * q + BBeta * (sin2q1q0 - sin2q1)) * sinA0
sinu2 = sinu1 * Cos(q) + cosu1 * Cos(A1) * Sin(q)
B2 = Atn(sinu2 / (Sqr(1 - e1 * e1) * Sqr(1 - sinu2 * sinu2))) * 180 / pi
lamuda = Atn(Sin(A1) * Sin(q) / (cosu1 * Cos(q) - sinu1 * Sin(q) * Cos(A1))) * 180 / pi
If (Sin(A1) > 0) Then
If (Sin(A1) * Sin(q) / (cosu1 * Cos(q) - sinu1 * Sin(q) * Cos(A1)) > 0) Then
lamuda = Abs(lamuda)
Else
lamuda = 180 - Abs(lamuda)
End If
Else
If (Sin(A1) * Sin(q) / (cosu1 * Cos(q) - sinu1 * Sin(q) * Cos(A1)) > 0) Then
lamuda = Abs(lamuda) - 180
Else
lamuda = -Abs(lamuda)
End If
End If
L2 = L1 * 180 / pi + lamuda - theta * 180 / pi
A2 = Atn(cosu1 * Sin(A1) / (cosu1 * Cos(q) * Cos(A1) - sinu1 * Sin(q))) * 180 / pi
If (Sin(A1) > 0) Then
If (cosu1 * Sin(A1) / (cosu1 * Cos(q) * Cos(A1) - sinu1 * Sin(q)) > 0) Then
A2 = 180 + Abs(A2)
Else
A2 = 360 - Abs(A2)
End If
Else
If (cosu1 * Sin(A1) / (cosu1 * Cos(q) * Cos(A1) - sinu1 * Sin(q)) > 0) Then
A2 = Abs(A2)
Else
A2 = 180 - Abs(A2)
End If
End If
Computation = format(L2, "0.00000000") & "," & format(B2, "0.00000000")
End Function
Private Function rad(ByVal angle_d As Double) As Double
rad = angle_d * pi / 180
End Function
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Post By：2018/12/11 15:52:00 [只看该作者]
