Since the CalCOFI station pattern is slanted relative to a latitudinal/longitudinal grid. The algorithm below is required to correctly calculate the distance between CalCOFI stations.
| Line | Sta (if calculated) | Latitude N | Longitude W |
| 93.3, 93 | 26.2 | 32.978982 | -117.272386 |
| 90.0 | 27.6 | 33.497430 | -117.741800 |
| 86.7, 87 | 32.1 | 33.917500 | -118.430800 |
| 83.3, 83 | 39.1 | 34.273350 | -119.308200 |
| 80.0 | 50.3 | 34.474500 | -120.476500 |
| 76.7, 77 | 47.23 | 35.148000 | -120.653000 |
| 73.3, 73 | 49.6 | 35.653333 | -121.221667 |
| 70.0 | 50.9 | 36.196667 | -121.723333 |
| 66.7, 67 | 46.9 | 36.903333 | -121.845000 |
| 63.3, 63 | 49.3 | 37.398333 | -122.425000 |
| 60.0 | 49.0 | 37.988333 | -122.815000 |
Basic Source Code (translated from F77 Fortran)
Public Static Sub OLDDS(LAT1!, Lon1!, D!, Liine$)
‘C
‘C — ROUTINE TO RETURN DISTANCE IN NAUTICAL MILES GIVEN TWO POSITIONS
‘C IN DECIMAL DEGREES. USES A METHOD THAT WILL MATCH THE RESULTS
‘C PRODUCED IN THE OLD VERTICAL SECTION PROGRAM.
‘C
‘C -> LAT0 — LATITUDE OF FIRST POINT. (DECIMAL DEGREES. SOUTH NEGATIVE.)
‘C -> LON0 — LONGITUDE OF FIRST POINT. (WEST NEGATIVE)
‘C -> LAT1 — LAT. OF SECOND POINT.
‘C -> LON1 — LONG. OF SECOND POINT.
‘C <- D — DISTANCE (NAUTICAL MILES) BETWEEN POINTS.
‘C
Dim COSD#
‘ Real LAT1, LON1, LAT2, LON2, D
‘ Real L, DLO, COSD, PI, F, A
PI# = 3.141592654
F# = PI# / 180
‘C
‘ INTRINSIC COS,ABS,SQRT
‘C
‘COSD#(A#) = Cos(A# * F#)
If frmSelData.txtDataIn(6) = “” Then
LineIn! = (Val(Liine$))
Else
LineIn! = Val(frmSelData.txtDataIn(6))
End If
D! = 0
Dist2Orig$ = “”
190
Select Case CInt(LineIn!)
Case 93, 94, 93.3
Lat0! = 32.969 ‘93.3 26.2 Google projection 2010; old value 32.95298 from Ralf & Nav Program
Lon0! = -117.2696 ‘Google projection 2010; old value -117.2664
Case 90, 91
Lat0! = 33.49743 ‘90.0 27.6 Google checked 2010 ‘4969634422
Lon0! = -117.7418 ‘745017037
Case 87, 86 , 86.7
Lat0! = 33.9175 ‘86.7 32.1 Google projection 2010; old .89568 ‘918195424
Lon0! = -118.4308 ‘Google projection 2010; old .419 ‘431669307
Case 83, 84 , 83.3
Lat0! = 34.27335 ‘83.3 39.1 Google checked 2010 ‘2739356345
Lon0! = -119.3082 ‘310048755
Case 80, 79
Lat0! = 34.4745 ‘80.0 50.3 Google projection 2010; old .4631 ‘4823190269
Lon0! = -120.4765 ‘Google projection 2010; old .4739 ‘485679527
Case 77, 76 , 76.7
Lat0! = 35.148 ‘76.7 47.23 Google checked 2010 ‘1446809515
Lon0! = -120.653 ‘650653673
Case 73 , 73.3
Lat0! = 35.6533333333
Lon0! = -121.221666667
Case 70
Lat0! = 36.1966666667
Lon0! = -121.723333333
Case 67 , 66.7
Lat0! = 36.9033333333
Lon0! = -121.845
Case 63
Lat0! = 37.3983333333
Lon0! = -122.425
Case 60 , 57.8, 57.9
Lat0! = 37.9883333333
Lon0! = -122.815
Case Else
Select Case LineIn!
Case 91.7, 91.6, 91.8, 92
Lat0! = 33.25773 ‘from Ralf & Nav Program
Lon0! = -117.4385
Case 88.5, 88.6, 88.4, 88
Lat0! = 33.69985 ‘from Ralf & Nav Program
Lon0! = -118.0522
Case 85.4, 85.5, 85.6
Lat0! = 34.01588 ‘from Ralf & Nav Program
Lon0! = -118.8243
Case 82, 81.9, 82.1
Lat0! = 34.435 ‘from Ralf & Nav Program
Lon0! = -119.955
Case 81.7, 81.8, 81
Lat0! = 34.4174 ‘from Ralf & Nav Program
Lon0! = -119.8033
Case 78.5, 78.4, 78.6
Lat0! = 34.77699 ‘from Ralf & Nav Program
Lon0! = -120.6302
Case Else
If LineIn! <> Val(Liine$) And LineIn! <> Val(StndL$) Then
LineIn! = Val(StndL$)
GoTo 190
Else
Exit Sub
End If
End Select
End Select
‘C
Lon0! = Lon0! * -1
L! = Abs(LAT1! – Lat0!)
DLO! = Abs(Lon1! – Lon0!)
If (DLO! > 180) Then DLO! = 360 – DLO!
‘C
L! = L! * 60
DLO! = DLO! * 60
DLO! = DLO! * Cos(F# * ((Lat0! + LAT1!) / 2))
D! = (Sqr(L! * L! + DLO! * DLO!)) * -1
Dist2Orig$ = Format(D!, “#0.00”)
If D! = 0 Then Dist2Orig$ = “”
End Sub