gcdist [options]{ x,y | site }
Reads from stdin two columns (u,v)
and computes great circle
distance
between (x,y), the "from"-site, and (u,v),
the "to"-site.
Longitudes x,u, latitudes y,v,
and result
are given in degrees or radians.
Instead of piping in a file, one "to"-site can be specified
with the -t option.
Instead of (x,y) you can enter 4-letter
site
names on the command
line;
the system will look up the environment to resolve $REFF.stacov
(if the REFF string already ends on .stacov
.scv
or .sv, ".stacov" will not be added).
As a new feature, also sta_pos files can be specified. The
system
will
recognize them by the substring "sta_pos"
occurring
in the name.
Options:
-r str - use this file as the
station
catalog. The file string may contain
wildcard
characters, in which case the first 10 files will be scanned.
The
-r option may be re-issued after the -t option for the case that
the
"from"- and "to"-stations
are listed in separate files.
Stacov and
sta_pos can be mixed.
-i file - use this file for input instead
of
reading from stdin.
-t u,v - the other
site's
(the "to"-site's) longitude,latitude is u,v; don't read
stdin
or file
-t site - the other site's name, 4-char.
The
locations are looked up in the site catalog.
-b str - locate first occurrence of
str
in record to read u,v from the columns beyond
-B str - locate last ...
-bn - read input
record
starting at column number n.
-c - print result and
a copy of the input string to stdout.
-C text - like -c, also print text (text
without blanks though!)
-km - output value in km
(else:
degrees)
-R -D
- input
values are in radians (default)or degrees
(can be
interweaved)
-a[r] - output
azimuths at
"to"-point followed by
"from"-point. Radians if -ar,
else degrees from North via East.
Column means character position in a record, not field number.
Examples:
In the following examples, the environment has been prepared by
setenv REFF /Bifrost/gps/RESULTS/HEFLIN/ref
(1)
gcdist -km -r /goa/sta_info/sta_pos -t CAGL
CASC
1587.874
uses as the station catalog /goa/sta_info/sta_pos for
both
stations
(2)
gcdist -km -t SVEG -r /goa/sta_info/sta_pos
CASC
3064.885
uses the station catalog derived from the $REFF
enviroment
variable
in the case of SVEG and /goa/sta_info/sta_pos in the
case
of CASC.
(3)
cat ~/gps/maps/swepos-labels.dat | gcdist -km
-c
ONSA
1041.973
18.1249 66.3180 12 0.0 0 1 ARJE
181.335
13.7181 56.0922 12 0.0 0 1 HASS
1043.902
.3363 50.8673 12 0.0 0 1 HERS
132.959
14.0596 57.7455 12 0.0 0 1 JONK
245.459
13.5056 59.4440 12 0.0 0 1 KARL
1251.427
21.0602 67.8776 12 0.0 0 1 KIRU
698.998
5.8096 52.1784 12 0.0 0 1 KOSG
406.148
14.8770 60.7221 12 0.0 0 1 LEKS
2211.776
-4.2497 40.4292 12 0.0 0 1 MADR
468.243
17.2585 60.5951 12 0.0 0 1 MART
1891.649
16.7045 40.6491 12 0.0 0 1 MATE
where ~/gps/maps/swepos-labels.dat contains
18.1249 66.3180
12 0.0 0 1 ARJE
13.7181 56.0922
12 0.0 0 1 HASS
.3363
50.8673 12 0.0 0 1 HERS
14.0596 57.7455
12 0.0 0 1 JONK
13.5056 59.4440
12 0.0 0 1 KARL
21.0602 67.8776
12 0.0 0 1 KIRU
5.8096
52.1784
12 0.0 0 1 KOSG
14.8770 60.7221
12 0.0 0 1 LEKS
-4.2497 40.4292
12 0.0 0 1 MADR
17.2585 60.5951
12 0.0 0 1 MART
16.7045 40.6491
12 0.0 0 1 MATE
etc.
will add the distance at the left on each line.
(4) with a station given by longitude and latitude
cat csdeu-lalodi.dat | gcdist -km -c -20,65
225.063
-16.29 66.33
-0.284
2873.574
13.17 46.33 -0.129
4060.057
20.13 36.99 -0.168
2872.973
12.50 46.05 -1.196
where csdeu-lalodi.dat contains
-16.29
66.33
-0.284
13.17
46.33
-0.129
20.13
36.99
-0.168
12.50
46.05
-1.196
(5)
gcdist -km -t 18.1249,66.3180
15.0332,59.2124
804.685
(is for ARJE OREB) uses explicit coordinates. No station files are
needed
(6) Azimuth from Borås to Onsala:
gcdist -a -km -t 11.94,57.39 12.59,57.72
46.854
-133.694 53.340
Output: azimuth of great circle at Onsala followed by the azimuth
at Borås, and the distance.
.bye