Ⅰ 高斯投影正‘反算公式间接进行换带计算的实质是什么
高斯投影换带计算利用了高斯投影的正、反算公式,其实质是:将椭球面上的大地坐标(B,L)作为过渡坐标。
将某投影带(如第1带,中央子午线为L1)内有关点的平面坐标(x1,y1)1,利用高斯投影反算公式换算成椭球面上的大地坐标(B,l1),进而得到L=L1+l1;根据邻带(如第2带,中央子午线为L2)的中央子午线来计算经差l2,即,l2=L-L2;然后再由大地坐标(B,l2)利用高斯投影正算公式得到邻带的平面坐标(x2,y2)。
Ⅱ 高斯投影换带计算
VERSION 5.00
Begin VB.Form Form1
Caption = "Form1"
ClientHeight = 5490
ClientLeft = 60
ClientTop = 345
ClientWidth = 7410
LinkTopic = "Form1"
ScaleHeight = 5490
ScaleWidth = 7410
StartUpPosition = 3 '窗口缺省
Begin VB.CommandButton Command3
Caption = "克氏计算"
Height = 495
Left = 2760
TabIndex = 19
Top = 4800
Width = 1215
End
Begin VB.CommandButton Command2
Caption = "退出"
Height = 615
Left = 3960
TabIndex = 18
Top = 4080
Width = 2415
End
Begin VB.CommandButton Command1
Caption = "计算"
Height = 615
Left = 360
TabIndex = 17
Top = 4080
Width = 2175
End
Begin VB.Frame Frame3
Caption = "输出坐标"
Height = 1455
Left = 120
TabIndex = 12
Top = 2280
Width = 6855
Begin VB.TextBox Text6
Height = 495
Left = 3960
TabIndex = 16
Text = "Text6"
Top = 360
Width = 2175
End
Begin VB.TextBox Text5
Height = 375
Left = 720
TabIndex = 14
Text = "Text5"
Top = 480
Width = 1455
End
Begin VB.Label Label8
Caption = "Y="
Height = 375
Left = 3480
TabIndex = 15
Top = 480
Width = 255
End
Begin VB.Label Label7
Caption = "X="
Height = 375
Left = 240
TabIndex = 13
Top = 480
Width = 255
End
End
Begin VB.Frame Frame2
Caption = "输入换代的中央子午线"
Height = 855
Left = 0
TabIndex = 5
Top = 1080
Width = 7095
Begin VB.TextBox Text4
Height = 375
Left = 5280
TabIndex = 9
Text = "Text4"
Top = 240
Width = 1335
End
Begin VB.TextBox Text3
Height = 375
Left = 1800
TabIndex = 8
Text = "Text3"
Top = 240
Width = 1095
End
Begin VB.Label Label6
Caption = "要换到的带的中央子午线"
Height = 495
Left = 3600
TabIndex = 11
Top = 240
Width = 1095
End
Begin VB.Label Label5
Caption = "所在的带的中央子午线"
Height = 495
Left = 240
TabIndex = 10
Top = 240
Width = 1095
End
Begin VB.Label Label3
Caption = "L0="
Height = 375
Left = 4920
TabIndex = 7
Top = 360
Width = 255
End
Begin VB.Label Label4
Caption = "L0="
Height = 255
Left = 1440
TabIndex = 6
Top = 360
Width = 375
End
End
Begin VB.Frame Frame1
Caption = "输入坐标"
Height = 975
Left = 0
TabIndex = 0
Top = 0
Width = 7095
Begin VB.TextBox Text2
Height = 375
Left = 4080
TabIndex = 4
Text = "Text2"
Top = 360
Width = 2295
End
Begin VB.TextBox Text1
Height = 375
Left = 360
TabIndex = 2
Text = "Text1"
Top = 360
Width = 2175
End
Begin VB.Label Label2
Caption = "Y="
Height = 375
Left = 3600
TabIndex = 3
Top = 360
Width = 375
End
Begin VB.Label Label1
Caption = "X="
Height = 375
Left = 120
TabIndex = 1
Top = 360
Width = 255
End
End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Dim x, y, b, L As Integer
Private Sub Command1_Click()
Dim x, y, L0, b1, c, bf, bf1, bf2, nf, z, b2, b3, b4, b5, b, L, l1 As Variant
x = Val(Text1.Text)
y = Val(Text2.Text)
L0 = Val(Text3.Text)
b1 = (x / 6367452.1328)
c = Cos(b1) * Cos(b1)
bf = b1 * 206264.806247096 + (52289760 + (2936975 + (2383 + 22 * c) * c) * c) * Sin(b1) * Cos(b1) / 10 ^ (10)
bf1 = bf / 206264.806247096
bf2 = Cos(bf1) * Cos(bf1)
nf = 6399596.652 - (21565.045 - (108.996 - 0.603 * bf2) * bf2) * bf2
z = y / (nf * Cos(bf1))
b2 = (0.5 + 0.00336975 * bf2) * Sin(bf1) * Cos(bf1)
b3 = 0.3333333 - (0.1666667 - 0.001123 * bf2) * bf2
b4 = 0.25 + (0.161612 + 0.005617 * bf2) * bf2
b5 = 0.2 - (0.16667 - 0.00878 * bf2) * bf2
b = bf - (1 - (b4 - 0.147 * z * z) * z * z) * z * z * b2 * 206264.806247096
L = (1 - (b3 - b5 * z * z) * z * z) * z * 206264.806247096
l1 = L0 * 3600 + L
Debug.Print l1
Debug.Print b
Dim l2, b6, c1, n, a0, a4, a6, a3, a5, x1, y1 As Variant
l2 = (l1 - Val(Text4.Text) * 3600) / 206264.806247096
b6 = b / 206264.806247096
c1 = Cos(b6) * Cos(b6)
n = 6399596.652 - (21565.045 - (108.996 - 0.603 * c1) * c1) * c1
a0 = 32144.5189 - (135.3646 - (0.7034 - 0.0041 * c1) * c1) * c1
a4 = (0.25 + 0.00253 * c1) * c1 - 0.04167
a6 = (0.167 * c1 - 0.083) * c1
a3 = (0.3333333 + 0.001123 * c1) * c1 - 0.1666667
a5 = 0.00878 - (0.1702 - 0.20382 * c1) * c1
x1 = 6367452.1328 * b / 206264.806247096 - (a0 - (0.5 + (a4 + a6 * l2 * l2) * l2 * l2) * l2 * l2 * n) * Cos(b6) * Sin(b6)
y1 = (1 + (a3 + a5 * l2 * l2) * l2 * l2) * l2 * n * Cos(b6)
Debug.Print x
Debug.Print y
Text5.Text = x1
Text6.Text = y1
End Sub
Private Sub Command3_Click()
Dim x, y, L0, b1, c, bf, bf2, bf1, nf, z, b2, b3, b4, b5, b, L, l1 As Variant
'可氏
x = Val(Text1.Text)
y = Val(Text2.Text)
L0 = Val(Text3.Text)
b1 = (x / 6367558.4969)
c = Cos(b1) * Cos(b1)
bf = b1 * 206264.806247096 + (50221746 + (293622 + (2350 + 22 * c) * c) * c) * Sin(b1) * Cos(b1) / 10 ^ (10)
bf1 = bf / 206264.806247096
bf2 = Cos(bf1) * Cos(bf1)
nf = 6399698.902 - (21562.267 - (108.973 - 0.612 * bf2) * bf2) * bf2
z = y / (nf * Cos(bf1))
b2 = (0.5 + 0.003369 * bf2) * Sin(bf1) * Cos(bf1)
b3 = 0.333333 - (0.166667 - 0.001123 * bf2) * bf2
b4 = 0.25 + (0.161612 + 0.00562 * bf2) * bf2
b5 = 0.2 - (0.1667 - 0.0088 * bf2) * bf2
b = bf - (1 - (b4 - 0.12 * z * z) * z * z) * z * z * b2 * 206264.806247096
L = (1 - (b3 - b5 * z * z) * z * z) * z * 206264.806247096
l1 = L0 * 3600 + L
Debug.Print l1
Debug.Print b
Dim l2, b6, c1, n, a0, a4, a6, a3, a5, x1, y1 As Variant
l2 = (l1 - Val(Text4.Text) * 3600) / 206264.806247096
b6 = b / 206264.806247096
c1 = Cos(b6) * Cos(b6)
n = 6399698.902 - (21562.267 - (108.973 - 0.612 * c1) * c1) * c1
a0 = 32140.404 - (135.3302 - (0.7092 - 0.004 * c1) * c1) * c1
a4 = (0.25 + 0.00252 * c1) * c1 - 0.04166
a6 = (0.166 * c1 - 0.084) * c1
a3 = (0.3333333 + 0.001123 * c1) * c1 - 0.1666667
a5 = 0.0083 - (0.1667 - (0.1968 + 0.004 * c1 * c1) * c1 * c1) * c1 * c1
x1 = 6367558.4969 * b / 206264.806247096 - (a0 - (0.5 + (a4 + a6 * l2 * l2) * l2 * l2) * l2 * l2 * n) * Cos(b6) * Sin(b6)
y1 = (1 + (a3 + a5 * l2 * l2) * l2 * l2) * l2 * n * Cos(b6)
Debug.Print x
Debug.Print y
Text5.Text = x1
Text6.Text = y1
End Sub
Private Sub Form_Load()
Text1.Text = ""
Text2.Text = ""
Text3.Text = ""
Text4.Text = ""
End Sub
Private Sub Command2_Click()
End
End Sub
Ⅲ 求大地测量学高斯正反算,高斯邻带换算C语言或者C#可以运行的程序。
只有高斯投影正反算,大地主题解算
当时太懒了,没写坐标换带,不过换带的程序是有,没源码
Ⅳ 我要用VB编一个能进行高斯投影正反算和邻带换算的程序 哪个高手帮帮忙 万分感谢
我有VB的,自己很多年前写的,一直用,但是正算->反算->正算后,Y坐标与原来的差了0.5-0.7mm,不知道怎么回事,这两年工作忙也没有时间再深究,但是这样的计算精度做控制足够了,如果楼主或是者是哪位同仁见此贴能顺便把这个问题解决了,咱们就一起进步了!代码如下:
'高斯坐标正算
Private Sub DadiZs()
Dim t As Double, Itp As Double, X0 As Double, N As Double, L0 As Double
Dim V As Double, ll As Double, W As Double, M As Double
Lat = Radian(Lat)
Lon = Radian(Lon)
L0 = Radian(Lo)
If Tq = 0 Then
a = 6378245 '54椭球参数
b = 6356863.01877305
ep = 0.006693421622966
ep1 = 0.006738525414683
f = (a - b) / a
c = a ^ 2 / b
d = b ^ 2 / a
X0 = 111134.8611 * (Lat * 180# / Pi) - (32005.7799 * Sin(Lat) + 133.9238 * (Sin(Lat)) ^ 3 + 0.6973 * (Sin(Lat)) ^ 5 + 0.0039 * (Sin(Lat)) ^ 7) * Cos(Lat)
'X0 = 111134.8611 * (Lat * 180# / Pi) - (32005.7798 * Sin(Lat) + 133.9238 * (Sin(Lat)) ^ 3 + 0.6972 * (Sin(Lat)) ^ 5 + 0.0039 * (Sin(Lat)) ^ 7) * Cos(Lat)
Else
a = 6378140 '75椭球参数
b = 6356755.28815753
ep = 0.006694384999588
ep1 = 0.006739501819473
f = (a - b) / a
c = a ^ 2 / b
d = b ^ 2 / a
X0 = 111133.0047 * (Lat * 180 / Pi) - (32009.8575 * Sin(Lat) + 133.9602 * (Sin(Lat)) ^ 3 + 0.6976 * (Sin(Lat)) ^ 5 + 0.0039 * (Sin(Lat)) ^ 7) * Cos(Lat)
End If
ll = Lon - L0
t = Tan(Lat)
Itp = ep1 * Cos(Lat) ^ 2
W = Sqr(1 - ep * Sin(Lat) ^ 2)
V = Sqr(1 + ep1 * Cos(Lat) ^ 2)
M = c / V ^ 3
N = a / W
'x = X0 + N * t * (Cos(Lat)) ^ 2 * ll ^ 2 / 2 + N * t * (5 - t * t + 9 * Itp + 4 * Itp * Itp) * (Cos(Lat)) ^ 4 * ll ^ 4 / 24 + N * t * (61 - 58 * t ^ 2 + t ^ 4 + 270 * Itp - 330 * t ^ 2 * Itp) * (Cos(Lat)) ^ 6 * ll ^ 6 / 720 + N * t * (1385 - 3111 * t ^ 2 + 543 * t ^ 4 - t ^ 6) * Cos(Lat) ^ 8 * ll ^ 8 / 40320
x = X0 + N * t * (Cos(Lat)) ^ 2 * ll ^ 2 / 2 + N * t * (5 - t * t + 9 * Itp ^ 2 + 4 * Itp ^ 4) * (Cos(Lat)) ^ 4 * ll ^ 4 / 24 + N * t * (61 - 58 * t ^ 2 + t ^ 4 + 270 * Itp ^ 2 - 330 * t ^ 2 * Itp ^ 2) * (Cos(Lat)) ^ 6 * ll ^ 6 / 720 + N * t * (1385 - 3111 * t ^ 2 + 543 * t ^ 4 - t ^ 6) * Cos(Lat) ^ 8 * ll ^ 8 / 40320
y = N * Cos(Lat) * ll + N * (1 - t * t + Itp) * (Cos(Lat)) ^ 3 * ll ^ 3 / 6 + N * (5 - 18 * t * t + t ^ 4 + 14 * Itp - 58 * Itp * t * t) * (Cos(Lat)) ^ 5 * ll ^ 5 / 120 + N * (61 - 479 * t ^ 2 + 179 * t ^ 4 - t ^ 6) * Cos(Lat) ^ 7 * ll ^ 7 / 5040
r = Sin(Lat) * ll + Sin(Lat) * (Cos(Lat)) ^ 2 * ll ^ 3 * (1 + 3 * Itp + 2 * Itp ^ 2) / 3 + Sin(Lat) * (Cos(Lat)) ^ 4 * ll ^ 5 * (2 - t * t) / 15
r = Degree(r)
y = y + 500000#
End Sub
'高斯反算
Private Sub DadiFs()
Dim t As Double, Itp As Double, X0 As Double, Bf As Double, N As Double
Dim v As Double, ll As Double, W As Double, M As Double, L0 As Double
L0 = Radian(Lo)
X0 = x * 0.000001
y = y - 500000#
If Tq = 0 Then
a = 6378245 '54椭球参数
b = 6356863.01877305
ep = 0.006693421622966
ep1 = 0.006738525414683
f = (a - b) / a
c = a ^ 2 / b
d = b ^ 2 / a
If X0 < 3 Then
Bf = 9.04353301294 * X0 - 0.00000049604 * X0 ^ 2 - 0.00075310733 * X0 ^ 3 - 0.00000084307 * X0 ^ 4 - 0.00000426055 * X0 ^ 5 - 0.00000010148 * X0 ^ 6
ElseIf X0 < 6 Then
Bf = 27.11115372595 + 9.02468257083 * (X0 - 3) - 0.00579740442 * (X0 - 3) ^ 2 - 0.00043532572 * (X0 - 3) ^ 3 + 0.00004857285 * (X0 - 3) ^ 4 + 0.00000215727 * (X0 - 3) ^ 5 - 0.00000019399 * (X0 - 3) ^ 6
End If
Else
a = 6378140 '75椭球参数
b = 6356755.28815753
ep = 0.006694384999588
ep1 = 0.006739501819473
f = (a - b) / a
c = a ^ 2 / b
d = b ^ 2 / a
If X0 < 3 Then
Bf = 9.04369066313 * X0 - 0.00000049618 * X0 ^ 2 - 0.00075325505 * X0 ^ 3 - 0.0000008433 * X0 ^ 4 - 0.00000426157 * X0 ^ 5 - 0.0000001015 * X0 ^ 6
ElseIf X0 < 6 Then
Bf = 27.11162289465 + 9.02483657729 * (X0 - 3) - 0.00579850656 * (X0 - 3) ^ 2 - 0.00043540029 * (X0 - 3) ^ 3 + 0.00004858357 * (X0 - 3) ^ 4 + 0.00000215769 * (X0 - 3) ^ 5 - 0.00000019404 * (X0 - 3) ^ 6
End If
End If
Bf = Bf * Pi / 180#
t = Tan(Bf)
Itp = ep1 * Cos(Bf) ^ 2
W = Sqr(1 - ep * Sin(Bf) ^ 2)
v = Sqr(1 + ep1 * Cos(Bf) ^ 2)
M = c / v ^ 3
N = a / W
Lat = Bf - 0.5 * v ^ 2 * t * ((y / N) ^ 2 - (5 + 3 * t * t + Itp - 9 * Itp * t * t) * (y / N) ^ 4 / 12 + (61 + 90 * t * t + 45 * t ^ 4) * (y / N) ^ 6 / 360)
ll = ((y / N) - (1 + 2 * t * t + Itp) * (y / N) ^ 3 / 6 + (5 + 28 * t * t + 24 * t ^ 4 + 6 * Itp + 8 * Itp * t * t) * (y / N) ^ 5 / 120) / Cos(Bf)
r = y * t / N - y ^ 3 * t * (1 + t * t - Itp) / (3 * N ^ 3) + y ^ 5 * t * (2 + 5 * t * t + 3 * t ^ 4) / (15 * N ^ 5)
Lat = Degree(Lat)
Lon = Degree(L0 + ll)
r = Degree(r)
End Sub
有了正反算,换带也就完成了!
用到的子程序:
Public Const Pi = 3.14159265358979, p = 206264.806
Public Cktq As String
'角度化弧度
Public Function Radian(a As Double) As Double
Dim Ro As Double
Dim c As Double
Dim Fs As Double
Dim Ib As Integer
Dim Ic As Integer
If a < 0 Then a = -a: t = 1
Ro = Pi / 180#
Ib = Int(a)
c = (a - Ib) * 100#
Ic = Int(c + 0.000000000001)
Fs = (c - Ic) * 100#
If t = 1 Then Radian = -(Ib + Ic / 60# + Fs / 3600#) * Ro Else Radian = (Ib + Ic / 60# + Fs / 3600#) * Ro
End Function
'弧度化角度
Public Function Degree(a As Double) As Double
Dim Bo As Double
Dim Fs As Double
Dim Im As Integer
Dim Id As Integer
If a < 0 Then a = -a: t = 1
Bo = a
Call DMS(Bo, Id, Im, Fs)
If t = 1 Then Degree = -(Id + Im / 100# + Fs / 10000#) Else Degree = Id + Im / 100# + Fs / 10000#
End Function
Public Sub DMS(a As Double, Id As Integer, Im As Integer, Fs As Double)
Dim Bo As Double
Dim c As Double
c = a
c = 180# / Pi * c
Id = Int(c)
Bo = (c - Id) * 60
Im = Int(Bo)
Fs = (Bo - Im) * 60
End Sub
'取位计算
Public Function Qw(a As Double, Ws As Integer) As Double
Qw = Int(a * 10 ^ Ws + 0.5) / 10 ^ Ws
End Function
另外,站长团上有产品团购,便宜有保证
Ⅳ 关于高一物理纸带实验中的问题,用这个公式s△=at^2该怎么算瞬时速度和逐差发又该怎么算写详细点
0-1间距s1=1.40cm
1-2间距s2=2.15cm
2-3间距s3=2.90cm
3-4间距s4=3.70cm
4-5间距s5=4.40cm
s1=v0t+1/2at^2,
s2=v1t+1/2at^2=(vo+at)t+1/2at^2=v0t+3/2at^2
所以S2-S1=at^2即a=(s2-s1)/t^2
但计算时一般采用逐差法,即
(1)(S3+S4)—(S1+S2)/4T^2 T=0.1s
a=0.76m/s2
(2)根据一段位移的平均速度等于这段时间的中间时刻的瞬时速度得出第四个计数点的速度
V=(S4+S5)/2T=0.40m/s
亲,给个好评吧
Ⅵ 河南省GPS控制点图形图像数据库建立
采用北京 1954 坐标系、高斯-克吕格投影 3°分带、1985 国家高程基准作为建库数据基础,河南省域跨越 37°、38°、39°带,测量的坐标数据存在三套数据,通常构建数据库时坐标系统的中央经线为 114°,即 38°带。为确保整个省域建库数据为统一的坐标系统,就应把 37°带、39°带内的控制点坐标进行换算,一般采用高斯投影正、反算公式间接进行换带计算,再将39°带、37°带的控制点坐标换算成 38°带的控制点坐标(表 3-5)。
表 3-5 GPS 控制点 3 度分带相邻带坐标换算对应表(河南省)
基于上述建库思路、文件组织、参数及属性结构设置等,对河南省 GPS 控制点成果数据进行整理汇总,在 MapGIS 软件平台上,基于简化后的 1∶5 万比例尺基础地理底图,构建了河南省 GPS 控制点图形图像数据库(图 3-7),实现了 GPS 控制点图形图像、空间位置、属性三者的综合管理,为后期的数据生产提供宝贵的基础资料,起到“一劳永逸”的功效。
图 3-7 河南省 GPS 控制点图形图像数据库
GPS 控制点图形图像数据库的特点主要有:
(1)三套编号系统,即标准编号、景内编号、测量编号。
(2)四套坐标数据,即北京 1954、西安 1980、WGS84、概略经纬度。
(3)挂接点位影像、图形及实地照片等,使控制点信息更加丰富。
(4)多种矢量数据的空间叠合。如与权属库、图幅、影像范围框间的叠合,便于查看控制点的区域性分布、与图幅及影像间的关系。一般利用影像头文件中的幅宽经纬度描述可直接在MapGIS 软件平台上对其空间范围进行定位,不受 MapGIS 库体基础坐标系统的影响,图 3-8 为河南省项目区内 SPOT 5 影像在以北京 1954 坐标系、3°分带、38°带为投影参数的 GPS 控制点图形图像库里空间位置情况。
图 3-8 SPOT 5 数据在 MapGIS 软件里的空间位置展现(河南省)
(5)查询检索直观便捷。可以利用属性字段、图形选取等方法,圈定某一作业区内的控制点数据。
Ⅶ 请教:在北京54坐标系中,已知两点坐标,求两点间的距离,但两点在相邻的两个带内,如何计算
“两个带”是什么意思?
直角坐标系就可以直接用公式计算
Ⅷ 打点计时器在纸带上打出来的点之间怎样计算能告诉我步骤吗
打点计时器每隔0.02s打一次点,你问的问题?打出的点?计算什么?是计算点的加速度还是瞬时速度还是什么呃,先看下面1、自由落体运动初始点的分析:看纸带的前两个点的距离是否接近2mm,接近2mm的纸带才是由静止开始的自由落体运动实验纸带。 2、实验纸带是否研究匀变速运动的分析:测量纸带上相邻各点的距离之差是否相等,若相等就是匀变速运动,否则就不是;即匀变速运动的纸带相邻两点的距离差满足 s(n)+s(n+1)=aT*T 3、计算匀变速运动中某点瞬时速度;由匀变速运动物体在某段位移的平均速度等于物体在该段位移中点时刻的瞬时速度;即 V(n)=〔s(n)+s(n+1)〕/2t s(n)指第N-1个计时点到第N个计时点的位移,s(n+1)指第N个计时点到第N+1个计时点的位移?〔s(n)+s(n+1)〕指第N-1个计时点到第N+1个计时点的位移.(即把要求的点包括在了他们中间即N处) ,t指发生两个相邻计数点(N-1到N,N到N+1)之间的时间间隔.2T就是时间间隔总和 4、计算匀变速运动的加速度: (1)、理想纸带的加速度计算:由于理想纸带描述的相邻两个计数点间的距离之差完全相等,即有:S2-S1=S3-S2=…=S(n)-S(n-1)=△S=aT*T;故其加速度 a=△S/(T*T) (2)、实际的实验纸带加速度计算:由于实验过程中存在一定的误差,导致各相邻两个计数点间的距离之差不完全相等,为减小计算加速度时产生的偶然误差,采用隔位分析法计算,可以减小运算量,方法是,用S1,S2,S3.......表示相邻计数点的距离,两计数点间的时间间隔为T,根据=aT*T有 S4-S1=(S4-S3)+(S3-S2)+(S2-S1)=3a1T*T 同理S5-S2=S6-S3=3a2T*T 求出a1=(S4-S1)/3T*T a2=(S5-S2)/3T*T a3=(S6-S3)/3T*T 再求平均值计算加速度 :a=(a1+a2+a3)/3
Ⅸ 在测量工作中哪些情况下需要进行邻带换算,如何换带计算
应该北京54坐标或者西安80坐标,要知道带号才行,知道带号要致知道所点哪县,便确定央经线,央经线用软件进行转换.
Ⅹ 控制测量中为什么要进行换带计算
高斯投影平面上的中央子午线投影为直线且长度不变,其余的子午线均为凹向中央子午线的曲线,其长度大于投影前的长度,离中央子午线越远长度变形越大。为了限制高斯投影的长度变形,必须依据中央子午线进行分带,把投影范围限制在中央子午线东、西两侧一定的狭长带内分别进行。但这又使得统一的坐标系分割成各带的独立坐标系。于是,因分带的结果产生了新的矛盾,即在生产建设中提出了各相邻带的互相联系的问题。这个问题是通过一个带的平面坐标换算到相邻带的平面坐标,简称为“邻带换算”