EXCEL的图像识别在链路预算中的应用

Posted 2021-04-06 卫星通信工程师

通过下面示例和步骤，说明如使用EXCEL根据输入的地点名称自动获取降雨衰减和卫星EIRP、G/T值等。

1、从网上找到ITU雨区分布图和亚洲9的Ku频段中国波束EIRP覆盖图

2、利用PS处理只保留几种代表符号或数值的颜色（这里建议使用EXCEL单元格的56种底色系列）、删除无用线条和杂色，调整好图像尺寸，保存为BMP24位的格式，如下面的状态

上面这个雨区分布图是墨卡托投影，在后面的EXCEL查询中做了转换

3、利用EXCEL的VBA代码读取上面两张覆盖图

  
    
    
  

   
     
     
   Sub Main()
   
     
     
   Const strBmpFile As String = "C:Mercator06.bmp"
   
     
     
   Dim arrByte() As Byte
   
     
     
   Dim PixelCol As Long, PixelRow As Long
   
     
     
   Dim CellCol As Long, CellRow As Long
   
     
     
   Dim i As Long, j As Long
   
     
     
   Dim lngPos As Long, Zeroize As Long
   
     
     
       
   
     
     
   Open strBmpFile For Binary As #1
   
     
     
   ReDim arrByte(LOF(1) - 1)
   
     
     
   Get #1, , arrByte
   
     
     
   Close #1
   
     
     
       
   
     
     
   For i = 0 To 3
   
     
     
   PixelCol = PixelCol + arrByte(i + 18) * 256 ^ i
   
     
     
   Next
   
     
     
   For i = 0 To 3
   
     
     
   PixelRow = PixelRow + arrByte(i + 22) * 256 ^ i
   
     
     
   Next
   
     
     
       If PixelCol Mod 4 <> 0 Then Zeroize = PixelCol Mod 4
   
     
     
       
   
     
     
   Cells.Clear
   
     
     
   For i = PixelRow To 1 Step -1
   
     
     
   CellRow = CellRow + 1
   
     
     
   CellCol = 0
   
     
     
   For j = 1 To PixelCol * 3 Step 3
   
     
     
   CellCol = CellCol + 1
   
     
     
   lngPos = 53 + j + (i - 1) * (PixelCol * 3 + Zeroize)
   
     
     
   Cells(CellRow, CellCol).Interior.Color = RGB(arrByte(lngPos + 2), arrByte(lngPos + 1), arrByte(lngPos))
   
     
     
   Next
   
     
     
   Next
   
     
     
   End Sub
   
     
     
   

  
    
    
  

4、利用EXCEL的VBA代码在两张覆盖表中填充对应符号或数字

Sub tst()Application.ScreenUpdating = FalseDim i, j, kWith Sheets("雨区颜色-1")For i = 1 To 3142For j = 1 To 3142k = .Cells(j, i).Interior.ColorIf k = 16777215 Then .Cells(j, i) = "A" ElseIf k = 65280 Then .Cells(j, i) = "B" ElseIf k = 16764160 Then .Cells(j, i) = "C" ElseIf k = 15066597 Then .Cells(j, i) = "D" ElseIf k = 13369343 Then .Cells(j, i) = "E" ElseIf k = 52735 Then .Cells(j, i) = "F" ElseIf k = 26367 Then .Cells(j, i) = "G" ElseIf k = 16738047 Then .Cells(j, i) = "H" ElseIf k = 10014157 Then .Cells(j, i) = "J" ElseIf k = 9764788 Then .Cells(j, i) = "K" ElseIf k = 39645 Then .Cells(j, i) = "L" ElseIf k = 65535 Then .Cells(j, i) = "M" ElseIf k = 16764415 Then .Cells(j, i) = "N" ElseIf k = 16777140 Then .Cells(j, i) = "P"Else .Cells(j, i) = "Q"    End IfNext jNext iEnd WithApplication.ScreenUpdating = TrueEnd Sub

数字化的覆盖图如下所示：

5、最后利用常用的链路预算EXCEL表格即可以实现根据输入地点自动获取相关数据了