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NAME: AACGMIDL PURPOSE: This library is a pure IDL version of the AACGM library ROUTINES: EQN_OF_TIME equation of time SOLAR_LOC find location of sun CNV_AACGM convert coordinates to/from magnetic/geographic CALC_MLT calculate magnetic local time LOAD_COEF load a set of AACGM coefficients
(See general/cotrans/aacgm/aacgmidl.pro)
Procedure: AACGM_PLOT
Description: Parameterized aacgm coordinate plotting routine. Run the routine with the appropriate coordinates
and it will plot a grid representing corrected geomagnetic coordinates in magnetic local time. If
you provide no local time, this routine will assume a local time of 2008-01-01/00:00:00 UT
Based upon aacgm_example of Eric Donovan @ U. Calgary
This routine uses AACGM code written by R.J. Barnes,Kile Baker, and Simon Wing. Their AACGM code was
modified slightly for use in the themis distribution.
Keywords(All input lats/lons are in degrees):
lat_center: The latitudinal center of the projection that you want to plot.(Default: 62)
lon_center: The longitudinal center of the projection that you want to plot.(Default: 256)
map_scale: Set the scale of the map presented. This is the same as the map scale argument to
other idl mapping routines. (Default: 42e6)
height: The height at which coordinates should be plotted. Note that coordinates may not be
calculable at low heights when plotting near the equator.(Default: 110)
local_time: The time in UT that should be assumed for MLT(default: '2008-01-01/00:00:00' UT)
lat_range: A two element array that represents the maximum and minimum latitude
that should be calculated. Smaller ranges speed up calculations.(Default: [50,70])
lon_range: A two element array that represents the maximum and minimum longitude
that should be calculated(in local magnetic coords) Smaller ranges speed up
calculations. (Default: [0,360])
lat_step: The size of latitudinal steps between lines. (Default:5)
lon_step: The size of longitudinal steps between lines. (Default:15)
lab_step: The number of N-S lines between labels (Default: 6)
n_lat_pts: The number of points per globe to use when drawing E-W lines. (Default: 360)
n_lon_pts: The number of points per globe to use when drawing N-S lines. (Default: 180)
lab_pos: The argument controls the position of the labels in the N-S direction
0: Draws the labels at the closest latitude to the equator(Default)
1: Draws the labels at the maximum latitude in the range.
-1: Draws the labels at the minimum latitude in the range
projection: The type of projection as a string. Default is 'orthographic', but you can select any
of the projections that are usually available to the map set routine. To see a list
of available projections type: 'MAP_PROJ_INFO, PROJ_NAMES=names & print,names'
You can also pass in any keywords that the plot command or the map_set command take. These can be useful for
things like controlling line thickness when exporting graphics.
Notes:
1. This routine loads the AACGM coefficients for the current time period( 2005-2010) If
this routine is being used for times outside this period, features need to be added to
utilize the aacgmidl routines that load other coordinate sets.
2. If you can think of any features that might ease usability please feel free to contact us.
$LastChangedBy: pcruce $
$LastChangedDate: 2008-09-18 15:48:50 -0700 (Thu, 18 Sep 2008) $
$LastChangedRevision: 3517 $
$URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/tags/spedas_4_0/general/cotrans/aacgm/aacgm_plot.pro $
(See general/cotrans/aacgm/aacgm_plot.pro)
NAME:
CALC_MLT
PURPOSE:
calculate magnetic local time for a given longitude
Calling sequence:
mlt=CALC_MLT(yr,t0,mlong)
t1 is the seconds from the start of year and
mlong is the magnetic longitude of the observing
point.
(See general/cotrans/aacgm/aacgmidl.pro)
NAME: CNVTIME PURPOSE: This provides an alternate entry point to CNV_MDHMS_SEC
(See general/cotrans/aacgm/cnvtime.pro)
NAME:
CNV_AACGM
PURPOSE:
convert to and from AACGM and Geographic coordinates
Calling sequence:
CNV_AACGM,in_lat,in_lon,height,out_lat,out_lon,r,error
the calculated latitude and longitude for the
given height are returned in out_lat,out_lon.
(See general/cotrans/aacgm/aacgmidl.pro)
NAME:
CNV_MDHMS_SEC
PURPOSE:
convert time from the form year, month, day, hour, minute, sec
to seconds of the year
Calling sequence:
t = cnv_mdhms_sec(yr, month, day, hour, minute, sec)
if the arguments are arrays, they must be the same size
OR
t = cnv_mdhms_sec(time_array)
where time_array is a 2-d intarr (6,n)
the first dimension gives the year, month, day, hour, minute, sec
(See general/cotrans/aacgm/cnvtime.pro)
NAME: CNV_SEC_MDHMS PURPOSE: Convert the time in seconds of the year to the form month, day hour, minutes, and seconds CALLING SEQUENCE: status = cnv_sec_mdhms(yr, mo, day, hour, minute, sec, yr_secs) All the arguments must be given. yr must be assigned a value (this determines whether you are in aleap year or not). Mo, day, hour, minute and sec must be declared to be normal integers and yr_secs must be given a value and must be a long integer. The status will be 0 for success and -1 for failure
(See general/cotrans/aacgm/cnvtime.pro)
NAME:
EQN_OF_TIME
PURPOSE:
equation of time for a given longitude and year
Calling sequence:
eqt = eqn_of_time(mean_lon,yr)
(See general/cotrans/aacgm/aacgmidl.pro)
NAME:
LOAD_COEF
PURPOSE:
load a set of AACGM coefficients
Calling sequence:
load_coef,fname
fname is the filename.
(See general/cotrans/aacgm/aacgmidl.pro)
NAME:
SOLAR_LOC
PURPOSE:
location of the sun for given year and time
Calling sequence:
solar_loc,yr,t1,mean_lon,dec
t1 is the seconds from the start of year.
the mean longitude and declination are returned
in mean_lon and dec as floats.
(See general/cotrans/aacgm/aacgmidl.pro)