1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
|
!-------------------------------------------------------------------------------
!
! This file is part of the WSPR applicaion, Weak Signal Propogation Reporter
!
! File Name: azdist.f90
! Description:
!
! Copyright (C) 2001-2014 Joseph Taylor, K1JT
! License: GPL-3+
!
! This program is free software; you can redistribute it and/or modify it under
! the terms of the GNU General Public License as published by the Free Software
! Foundation; either version 3 of the License, or (at your option) any later
! version.
!
! This program is distributed in the hope that it will be useful, but WITHOUT
! ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
! FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
! details.
!
! You should have received a copy of the GNU General Public License along with
! this program; if not, write to the Free Software Foundation, Inc., 51 Franklin
! Street, Fifth Floor, Boston, MA 02110-1301, USA.
!
!-------------------------------------------------------------------------------
subroutine azdist(MyGrid,HisGrid,utch,nAz,nEl,nDmiles,nDkm,nHotAz,nHotABetter)
character*6 MyGrid,HisGrid,mygrid0,hisgrid0
real*8 utch,utch0
logical HotABetter,IamEast
real eltab(22),daztab(22)
data eltab/18.,15.,13.,11.,9.,8.,7.,6.,5.3,4.7,4.,3.3,2.7, &
2.,1.5,1.,0.8,0.6,0.4,0.2,0.0,0.0/
data daztab/21.,18.,16.,15.,14.,13.,12.,11.,10.7,10.3,10., &
10.,10.,10.,10.,10.,10.,9.,9.,9.,8.,8./
data mygrid0/" "/,hisgrid0/" "/,utch0/-999.d0/
save
if(MyGrid.eq.HisGrid) then
naz=0
nel=0
ndmiles=0
ndkm=0
nhotaz=0
nhotabetter=1
go to 999
endif
if(mygrid.eq.mygrid0 .and. hisgrid.eq.hisgrid0 .and. &
abs(utch-utch0).lt.0.1666667d0) go to 900
utch0=utch
mygrid0=mygrid
hisgrid0=hisgrid
utchours=utch
if(MyGrid(5:5).eq.' ') MyGrid(5:5)='m'
if(MyGrid(6:6).eq.' ') MyGrid(6:6)='m'
if(HisGrid(5:5).eq.' ') HisGrid(5:5)='m'
if(HisGrid(6:6).eq.' ') HisGrid(6:6)='m'
if(MyGrid.eq.HisGrid) then
Az=0.
Dmiles=0.
Dkm=0.0
El=0.
HotA=0.
HotB=0.
HotABetter=.true.
go to 900
endif
call grid2deg(MyGrid,dlong1,dlat1)
call grid2deg(HisGrid,dlong2,dlat2)
call geodist(dlat1,dlong1,dlat2,dlong2,Az,Baz,Dkm)
j=nint(Dkm/100.0)-4
if(j.lt.1) j=1
if(j.gt.21)j=21
ndkm=Dkm/100
d1=100.0*ndkm
u=(Dkm-d1)/100.0
El=eltab(j) + u * (eltab(j+1)-eltab(j))
daz=daztab(j) + u * (daztab(j+1)-daztab(j))
Dmiles=Dkm/1.609344
tmid=mod(UTChours-0.5*(dlong1+dlong2)/15.0+48.0,24.0)
IamEast=.false.
if(dlong1.lt.dlong2) IamEast=.true.
if(dlong1.eq.dlong2 .and. dlat1.gt.dlat2) IamEast=.false.
azEast=baz
if(IamEast) azEast=az
if((azEast.ge.45.0 .and. azEast.lt.135.0) .or. &
(azEast.ge.225.0 .and. azEast.lt.315.0)) then
! The path will be taken as "east-west".
HotABetter=.true.
if(abs(tmid-6.0).lt.6.0) HotABetter=.false.
if((dlat1+dlat2)/2.0 .lt. 0.0) HotABetter=.not.HotABetter
else
! The path will be taken as "north-south".
HotABetter=.false.
if(abs(tmid-12.0).lt.6.0) HotABetter=.true.
endif
if(IamEast) then
HotA = Az - daz
HotB = Az + daz
else
HotA = Az + daz
HotB = Az - daz
endif
if(HotA.lt.0.0) HotA=HotA+360.0
if(HotA.gt.360.0) HotA=HotA-360.0
if(HotB.lt.0.0) HotB=HotB+360.0
if(HotB.gt.360.0) HotB=HotB-360.0
900 continue
naz=nint(Az)
nel=nint(el)
nDmiles=nint(Dmiles)
nDkm=nint(Dkm)
nHotAz=nint(HotB)
nHotABetter=0
if(HotABetter) then
nHotAz=nint(HotA)
nHotABetter=1
endif
999 return
end subroutine azdist
|