Subroutine  bafricht.

CREATE PROCEDURE dd_bafricht
    @rca char(4),
    @rcb char(4),
    @rq  char(1),
    @fca char(4),
    @fcb char(4),
    @fq  char(1)
AS
BEGIN
/* compute distance and direction */
DECLARE
    @i          int,
    @rbr        int,
    @vbr        int,
    @rle        int,
    @vle        int,
    @graden     int,
    @kms        int,
    @err        int,
    @dum        char(80)

/* select dist=null,dir=null */

/* corrigeer voor kwadranten en converteer naar integers */
/* bereken geograf coordinaten uit Amfrt coordinaten */

/* ringcoordinaten */
   exec @err = dd_todecgeo @rca,@rcb,@rq,@rbr output,@rle output
   if @err != 1 return

/* vindcoordinaten */
   exec @err = dd_todecgeo @fca,@fcb,@fq,@vbr output,@vle output
   if @err != 1 return

/* de coordinaten zijn bruikbaar voor de berekeningen */
/* bereken met loxodroom de afstand en richting */
   exec @err = dd_loxod @rbr,@rle,@vbr,@vle,@kms output, @graden output
   if @err != 1 return

   select dist=@kms,dir=@graden
   return
END
GO
  

Subroutine  todecgeo.

/****** Object:  Stored Procedure dbo.dd_todecgeo    Script Date: 16-4-2003 11:19:09 ******/

CREATE  PROCEDURE dd_todecgeo
    @ca   char(4),
    @cb   char(4),
    @q    char(1)   output,
    @br   int       output,
    @le   int       output
AS
BEGIN
/* maak van karakters integers en */
/* corrigeer lengte en breedte voor kwadrant */
/* roep proc aan voor conversie van Amfrt naar geogr coordinaten */

if charindex('-',@ca) = 0 and
   charindex('-',@cb) = 0
   begin  /* naukeurge coordinaten: dus bereken */

   /* maak van Amerfoort coordinaten geografische coordinaten */
   if @q='N' exec dd_amtogeo2 @ca out,@cb out,@q out

   /* maak van tekst integers */
   select @br=convert(int,@ca)
   select @le=convert(int,@cb)


   if @q='E' return 1

   if @q='W'
    begin
    select @le=-@le
    return 1
    end

   if @q='S'
    begin
    select @br=-@br
    return 1
    end

   if @q='U'
    begin
    select @le=-@le
    select @br=-@br
    return 1
    end

   if @q='C'
    begin
    select @le=@le+10000
    return 1
    end

   if @q='A'
    begin
    select @le=@le+10000
    select @br=-@br
    return 1
    end

   if @q='H'
    begin
    select @le=@le+10000
    select @le=-@le
    return 1
    end

   if @q='P'
    begin
    select @le=@le+10000
    select @le=-@le
    select @br=-@br
    return 1
    end

   else /* coordinaat onnauwkeurig */
    return 2
   end

   return 3 /* kwadrant onbekend */

END
GO

Subroutine  loxod.

CREATE PROCEDURE dd_loxod
    @rbr        int,
    @rle        int,
    @vbr        int,
    @vle        int,
    @kms        int output,
    @graden     int output
AS
BEGIN
/* Berekening van richting en afstand met de loxodroom
 * volgens Imboden: Vogelwarte 26,1972: 336-346
 */
declare
    @pi    float,
    @erd   float,
    @rad   float,
    @hl    float,
    @al    float,
    @ala   float,
    @alo   float,
    @bla   float,
    @blo   float,
    @delo  float,
    @dela  float,
    @pha   float,
    @phb   float,
    @deph  float,
    @desb  float,
    @wl    float,
    @dl    float,
    @phna  float,
    @phnb  float,
    @a     float

/* return 1 bij geen fouten */

      select @kms=0
      select @graden=0
      select @pi=3.1415926
      select @erd=6368.0
      select @rad=57.295779

      /* coordinaten buiten minimum en maximum return=2 */
      if (@rbr> 9000 or @rbr< -9000) return 2
      if (@vbr> 9000 or @vbr< -9000) return 2
      if (@rle>18000 or @rle<-18000) return 2
      if (@vle>18000 or @vle<-18000) return 2

      select @hl=0
      select @al=0
      select @dl=0
      select @wl=0

      /* van graden+minuten naar decimale graden */
      exec dd_todec @rbr,@ala output
      exec dd_todec @rle,@alo output
      exec dd_todec @vbr,@bla output
      exec dd_todec @vle,@blo output

      select @dela=@bla-@ala
      select @delo=@blo-@alo

      if (@dela=0 and @delo=0) return 1 /* ringplaats=vindplaats */


      select @a=abs(@delo)


      if @a-180 > 0
       begin
       if @delo <= 0   select @delo=@delo+360
            else       select @delo=@delo-360
       end

      select @pha=@ala/@rad
      select @phb=@bla/@rad
      select @deph=@dela/@rad
      select @desb=@a/@rad

      if @delo != 0
       begin
       if @dela = 0
        begin
         select @dl=@desb*cos(@pha)
         select @wl=90
        end
        else
        begin
         select @phna=(45+@ala/2)/@rad
         select @phnb=(45+@bla/2)/@rad
         select @a=atan(@desb/(log(abs(tan(@phnb)))-log(abs(tan(@phna)))))
         select @dl=@deph/cos(@a)
         if @dela<0 select @a=@pi+@a
         select @wl=@a*@rad
        end
       end
       else
       begin
        select @dl=@deph
        select @wl=360
        if @phb<@pha select @wl=180
       end

      select @dl=abs(@dl)*@erd
      if @delo<0 select @wl=360-@wl
      select @graden=@wl+0.5
      select @kms=@dl+0.5
      if @graden=0 select @graden=360
      if @kms=0    select @graden=0

/*   select @kms,@graden */
      return 1

END
GO