Example_5_06.m

% ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
% Example_5_06
% ~~~~~~~~~~~~
%{
  This program uses Algorithm 5.3 to obtain the local sidereal
  time from the data provided in Example 5.6.
 
  lst   - local sidereal time (degrees)
  EL    - east longitude of the site (west longitude is negative):
             degrees (0 - 360)
             minutes (0 - 60)
             seconds (0 - 60)
  WL    - west longitude
  year  - range: 1901 - 2099
  month - range: 1 - 12
  day   - range: 1 - 31
  ut    - universal time
             hour (0 - 23)
             minute (0 - 60)
             second (0 - 60)
 
  User m-function required: LST
%}
% ----------------------------------------------

clear all; clc

%...Data declaration for Example 5.6:
%   East longitude:
degrees = 139;
minutes = 47;
seconds = 0;

%   Date:
year    = 2004;
month   = 3;
day     = 3;

%   Universal time:
hour    = 4;
minute  = 30;
second  = 0;
%...
 
%...Convert negative (west) longitude to east longitude:  
if degrees < 0
    degrees = degrees + 360;
end

%...Express the longitudes as decimal numbers:   
EL = degrees + minutes/60 + seconds/3600;
WL = 360 - EL;

%...Express universal time as a decimal number:
ut = hour + minute/60 + second/3600;

%...Algorithm 5.3:
lst = LST(year, month, day, ut, EL);

%...Echo the input data and output the results to the command window:
fprintf('-----------------------------------------------------')
fprintf('\n Example 5.6: Local sidereal time calculation\n')
fprintf('\n Input data:\n');
fprintf('\n   Year                      = %g', year)
fprintf('\n   Month                     = %g', month)
fprintf('\n   Day                       = %g', day)
fprintf('\n   UT (hr)                   = %g', ut)
fprintf('\n   West Longitude (deg)      = %g', WL)
fprintf('\n   East Longitude (deg)      = %g', EL)
fprintf('\n\n');

fprintf(' Solution:')

fprintf('\n');
fprintf('\n  Local Sidereal Time (deg) = %g', lst)
fprintf('\n  Local Sidereal Time (hr)  = %g', lst/15)

fprintf('\n-----------------------------------------------------\n')
% ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~