Data C : Airport Data File : Great Circle Distance Calculator

<% Dim regionID 'air regions dropdown Dim jmSQL, rsAirDropR '---create dsn-less conn----- Dim DB, Dir, Path, f, airports DB = "_data\airports.mdb" Dir = Request.ServerVariables("SCRIPT_NAME") Dir = StrReverse(Dir) Dir = Mid(Dir, InStr(1, Dir, "/")) Dir = StrReverse(Dir) Path = Server.MapPath(Dir) & "\" f = "airports.dsn" airports = "filedsn=" & Path & f & ";DefaultDir=" & Path & _ ";DBQ=" & Path & DB & ";" '----------------------------- jmSQL = "SELECT DISTINCT apTable.REGION FROM apTable;" Set rsAirDropR = Server.CreateObject("ADODB.Recordset") rsAirDropR.Open jmSQL, airports If Not rsAirDropR.EOF Then %>
<% Else regionID = CStr(Request.QueryString("REGION")) %> <% End If %> <% Dim countryID regionID = CStr(Request.QueryString("REGION")) 'air regions dropdown Dim countrySQL, rsAirDropC countrySQL = "SELECT DISTINCT apTable.REGION, apTable.COUNTRY FROM apTable WHERE apTable.REGION = '" & regionID & "';" Set rsAirDropC = Server.CreateObject("ADODB.Recordset") rsAirDropC.Open countrySQL, airports If Not rsAirDropC.EOF Then %> <% End If %> <% Dim cityID cityID = CStr(Request.QueryString("city")) countryID = CStr(Request.QueryString("country")) regionID = CStr(Request.QueryString("REGION")) 'air regions dropdown Dim citySQL, rsAirDropCN citySQL = "SELECT DISTINCT apTable.CITY_NAME FROM apTable WHERE apTable.COUNTRY = '" citySQL = citySQL & Replace(countryID,"'","''") & "';" Set rsAirDropCN = Server.CreateObject("ADODB.Recordset") rsAirDropCN.Open citySQL, airports If Not rsAirDropCN.EOF Then %> <% End If %> <% Dim thisRegion, thisCountry, thisCity thisRegion = CStr(Request.QueryString("region")) thisCountry = CStr(Request.QueryString("country")) thisCity = CStr(Request.QueryString("city")) 'air regions dropdown Dim showcitySQL, rsShowCN showcitySQL = "SELECT DISTINCT apTable.AIRP_NAME, apTable.LENGTH, apTable.ELEV, apTable.LOCATION FROM apTable WHERE apTable.CITY_NAME = '" showcitySQL = showcitySQL & Replace(thisCity,"'","''") & "';" Set rsShowCN = Server.CreateObject("ADODB.Recordset") rsShowCN.Open showcitySQL, airports If Not rsShowCN.EOF Then 'first variable for location data Dim locOne,airportOne locOne = rsShowCN("LOCATION") airportOne = rsShowCN("AIRP_NAME") %> <% Do While Not rsShowCN.EOF %> <% rsShowCN.MoveNext loop %> <% End If %> <% 'close airports one rs rsShowCN.Close Dim regionTwoID 'air regions dropdown Dim jmSQLtwo, rsAirDropRtwo jmSQLtwo = "SELECT DISTINCT apTable.REGION FROM apTable;" Set rsAirDropRtwo = Server.CreateObject("ADODB.Recordset") rsAirDropRtwo.Open jmSQLtwo, airports If Not rsAirDropRtwo.EOF Then %>

Step One Departing From
Regions	Countries	Cities
<%If Request.QueryString("region") = "" Then%> Select a Region <%Else regionID = Request.QueryString("region")%> <%=regionID%> <%End If%> <% Do While Not rsAirDropR.EOF %> "><%=rsAirDropR("REGION")%> <% rsAirDropR.MoveNext loop %>	<%If Request.QueryString("country") = "" Then%> Select a Country <%Else countryID = Request.QueryString("country") %> <%=countryID%> <%End If%> <% Do While Not rsAirDropC.EOF %> "><%=rsAirDropC("COUNTRY")%> <% rsAirDropC.MoveNext loop %>	<% If Request.QueryString("city") = "" Then%> Select a City <%Else cityID = CStr(Request.QueryString("city"))%> <%=cityID%> <%End If%> <% Do While Not rsAirDropCN.EOF %> "><%=rsAirDropCN("CITY_NAME")%> <% rsAirDropCN.MoveNext loop %>
<%=airportOne%>
Length: <%=rsShowCN("LENGTH")%>(ft)	Elevation: <%=rsShowCN("ELEV")%>(ft)	Location: <%=locOne%>

<% Else regionTwoID = CStr(Request.QueryString("aregionTwo")) %> <% End If %> <% Dim countryIDtwo regionTwoID = CStr(Request.QueryString("aregionTwo")) 'air regions dropdown Dim countrySQLtwo, rsAirDropCtwo countrySQLtwo = "SELECT DISTINCT apTable.REGION, apTable.COUNTRY FROM apTable WHERE apTable.REGION = '" & regionTwoID & "';" Set rsAirDropCtwo = Server.CreateObject("ADODB.Recordset") rsAirDropCtwo.Open countrySQLtwo, airports If Not rsAirDropCtwo.EOF Then %> <% End If %> <% Dim cityIDtwo cityIDtwo = CStr(Request.QueryString("cityTwo")) countryIDtwo = CStr(Request.QueryString("countryTwo")) regionTwoID = CStr(Request.QueryString("aregionTwo")) 'air regions dropdown Dim citySQLtwo, rsAirDropCNtwo citySQLtwo = "SELECT DISTINCT apTable.CITY_NAME FROM apTable WHERE apTable.COUNTRY = '" citySQLtwo = citySQLtwo & Replace(countryIDtwo,"'","''") & "';" Set rsAirDropCNtwo = Server.CreateObject("ADODB.Recordset") rsAirDropCNtwo.Open citySQLtwo, airports If Not rsAirDropCNtwo.EOF Then %> <% End If %> <% Dim thisRegionTwo, thisCountryTwo, thisCityTwo thisRegionTwo = CStr(Request.QueryString("aregionTwo")) thisCountryTwo = CStr(Request.QueryString("countryTwo")) thisCityTwo = CStr(Request.QueryString("cityTwo")) 'air regions dropdown Dim showcitySQLTwo, rsShowCNTwo showcitySQLTwo = "SELECT DISTINCT apTable.AIRP_NAME, apTable.LENGTH, apTable.ELEV, apTable.LOCATION FROM apTable WHERE apTable.CITY_NAME = '" showcitySQLTwo = showcitySQLTwo & Replace(thisCityTwo,"'","''") & "';" Set rsShowCNTwo = Server.CreateObject("ADODB.Recordset") rsShowCNTwo.Open showcitySQLTwo, airports If Not rsShowCNTwo.EOF Then 'second variable for location data Dim locTwo, airportTwo locTwo = rsShowCNTwo("LOCATION") airportTwo = rsShowCNTwo("AIRP_NAME") %> <% Do While Not rsShowCNTwo.EOF %> <% rsShowCNTwo.MoveNext loop %> <% End If %>

Step Two To Arrive In
Regions	Countries	Cities
<%If Request.QueryString("aregionTwo") = "" Then%> Select a Region <%Else regionTwoID = Request.QueryString("aregionTwo")%> <%=regionTwoID%> <%End If%> <% Do While Not rsAirDropRtwo.EOF %> "><%=rsAirDropRtwo("REGION")%> <% rsAirDropRtwo.MoveNext loop %>	<%If Request.QueryString("countryTwo") = "" Then%> Select a Country <%Else countryIDtwo = Request.QueryString("countryTwo") %> <%=countryIDtwo%> <%End If%> <% Do While Not rsAirDropCtwo.EOF %> "><%=rsAirDropCtwo("COUNTRY")%> <% rsAirDropCtwo.MoveNext loop %>	<% If Request.QueryString("cityTwo") = "" Then%> Select a City <%Else cityIDtwo = CStr(Request.QueryString("cityTwo"))%> <%=cityIDTwo%> <%End If%> <% Do While Not rsAirDropCNtwo.EOF %> "><%=rsAirDropCNTwo("CITY_NAME")%> <% rsAirDropCNtwo.MoveNext loop %>
<%=airportTwo%>
Length: <%=rsShowCNTwo("LENGTH")%>(ft)	Elevation: <%=rsShowCNTwo("ELEV")%>(ft)	Location: <%=locTwo%>

<% if locTwo = "" Then Response.Write("") Else '---------STEP ONE------------ 'get latitute and longitude for both airports Dim latOne, latmidOne, dirOne, equalsOne Dim longOne, longmidOne, dirLgOne, equalsLgOne Dim locOneLength, locTwoLength 'latitude for airport one locOneLength = Len(locOne) latOne = Left(locOne, 2) latmidOne = Mid(locOne, 3, 2) dirOne = Mid(locOne, 5, 1) latmidOne = CInt(latmidOne) latmidOne = latmidOne / 60 equalsOne = latOne + latmidOne equalsOne = Round(equalsOne, 3) 'longitude for airport one If locOneLength = 12 Then longOne = Mid(locOne, 7,3) longmidOne = Mid(locOne, 10, 2) Else longOne = Mid(locOne, 7,2) longmidOne = Mid(locOne, 9, 2) End If dirLgOne = Right(locOne, 1) longmidOne = CInt(longmidOne) longmidOne = longmidOne / 60 equalsLgOne = longOne + longmidOne Dim latTwo, latmidTwo, dirTwo, equalsTwo Dim longTwo, longmidTwo, longLgTwo, dirLgTwo, equalsLgTwo 'latitude for airport Two locTwoLength = Len(locTwo) latTwo = Left(locTwo, 2) latmidTwo = Mid(locTwo, 3, 2) dirTwo = Mid(locTwo, 5, 1) latmidTwo = CInt(latmidTwo) latmidTwo = latmidTwo / 60 equalsTwo = latTwo + latmidTwo equalsTwo = Round(equalsTwo, 3) 'longitude for airport Two If locTwoLength = 12 Then longTwo = Mid(locTwo, 7,3) longmidTwo = Mid(locTwo, 10, 2) Else longTwo = Mid(locTwo, 7,2) longmidTwo = Mid(locTwo, 9, 2) End If dirLgTwo = Right(locTwo, 1) longmidTwo = CInt(longmidTwo) longmidTwo = longmidTwo / 60 equalsLgTwo = longTwo + longmidTwo '---------STEP TWO------------ 'determine angle at earth center from North Pole for each airport 'south is positive 'airport one Dim AOB, vAOB, AOC, vAOC If dirOne = "N" Then vAOB = "-" & CStr(equalsOne) vAOB = CDbl(vAOB) vAOB = Round(vAOB, 2) Else vAOB = equalsOne vAOB = Round(vAOB, 2) End If AOB = 90 + vAOB 'airport two If dirTwo = "N" Then vAOC = "-" & CStr(equalsTwo) vAOC = CDbl(vAOC) vAOC = Round(vAOC, 2) Else vAOC = equalsOne vAOC = Round(vAOC, 2) End If AOC = 90 + vAOC '---------STEP THREE------------ 'looking down polar axis determine angle between the two points 'east is positive Dim BOCpolar, vequalsLgOne, vequalsLgTwo If dirLgOne = "W" Then 'vequalsLgOne = "-" & CStr(equalsLgOne) 'vequalsLgOne = CDbl(vequalsLgOne) vequalsLgOne = equalsLgOne Else vequalsLgOne = equalsLgOne End If If dirLgTwo = "W" Then 'vequalsLgTwo = "-" & CStr(equalsLgTwo) 'vequalsLgTwo = CDbl(vequalsLgTwo) vequalsLgTwo = equalsLgTwo Else vequalsLgTwo = equalsLgTwo End If BOCpolar = (vequalsLgOne) + (vequalsLgTwo) BOCpolar = Round(BOCpolar, 2) '---------STEP FOUR------------ 'true anlge between two points referenced to the centre (BOCtrue) 'must convert degrees to radians - degrees times pi/180 Dim cosAOB, cosAOC, cosBOCp, sinAOB Dim sinAOC, cosBOCtrue, BOCtrue, greatCircleDist, greatCircleDistKM Dim pi, toDegrees, toRadians, firstpart, secondpart pi = 3.1415926535897932 toDegrees = 180 / pi toRadians = pi / 180 AOB = AOB * toRadians cosAOB = cos(AOB) AOC = AOC * toRadians cosAOC = cos(AOC) BOCpolar = BOCpolar * toRadians cosBOCp = cos(BOCpolar) sinAOB = sin(AOB) sinAOC = sin(AOC) firstpart = cosAOB * cosAOC secondpart = cosBOCp * sinAOB * sinAOC cosBOCtrue = firstpart + secondpart BOCtrue = Atn(-cosBOCtrue / Sqr(-cosBOCtrue * cosBOCtrue + 1)) + 2 * Atn(1) BOCtrue = BOCtrue * toDegrees BOCtrue = Round(BOCtrue, 2) greatCircleDist = BOCtrue * 60 greatCircleDist = Int(greatCircleDist) greatCircleDistKM = (greatCircleDist * 1.852) greatCircleDistKM = CInt(greatCircleDistKM) %>

Great Circle distance
<%=airportOne%>	<%=locOne%>	Using 60nm per degree gives:
<%=airportTwo%>	<%=locTwo%>	<%=greatCircleDist%>nm (<%=greatCircleDistKM%>km)

<% End If %>

Please note location data takes the following format: 4853N = 48 deg 53 min North.

This data file contains information on the main airports around the world, gathered from various public sources. The data is useful in identifying the runway conditions (length and height) and estimating the geometrical distance between city pairs on a particular route (eg. Los Angeles to Tokyo).

To use the online great circle distance, please select a Region, Country and City for Aiport One. Then choose a Region, Country and City for Airport Two. This will then calculate the Great Circle Distance between the selected Airports.