xgpstime.m

GPS TOOLBOX包含以下内容： 1、GPS相关常量和转换因子； 2、角度变换； 3、坐标系转换： &#61656 点变换； &#61656 矩阵变换； &#61656 向量变换

%                                 xgpstime.m
%  Scope:   This MATLAB program performs the following GPS time related 
%           transformation:
%            1) from (year, month, day) to (GPS week, GPS roll number, day of
%               week) 
%            2) from (GPS week, day of week, GPS roll number) to (day of week,
%               day, month, year)
%            3) from (day of week, hour, minute, second) to (time of week)
%            4) from (time of week) to (day of week, hour, minute, second)
%  Usage:   xgpstime
%  Inputs:   - name of the output file if selected (the default is the screen)
%            1) For the (year, month, day) to (GPS week, GPS roll number, day of
%               week):
%               - year (1980 and greater)
%               - month (1 to 12)
%               - day (1 to 31)
%            2) For the (GPS week, day of week, GPS roll number) to  
%               (day of week, day, month, year): 
%               - GPS week (0 to 1023)
%               - day of week (0 to 6)
%               - GPS roll number (0 to ...)
%            3) For the (day of week, hour, minute, second) to (time of week):
%               - day of week (0 to 6)
%               - hour (0 to 23) 
%               - minute (0 to 59)
%               - second (0 to 60)
%            4) For the (time of week) to (day of week, hour, minute, second):
%               - time of week (0 to 604800)
%  Outputs:  - input/output data stored into the specified output file or
%              displayed on screen
%  Last update:  09/05/00
%  Copyright (C) 1999-00  by LL Consulting. All Rights Reserved.

clear  

trefgps = datenum(1980,1,6);         %  gps reference day

yes = 'y';
answer = yes;

disp(' ');
answer1 = input('Do you want to save the results? (y/n)[n] --> ','s');
disp(' ');
if (strcmp(answer1,yes) == 1)
   f2 = input('Specify the output filename  -->  ','s');
   disp(' ');
else
   f2 = 1;      %  output to the screen
end

while (strcmp(answer,yes) == 1)    

   disp('Select:   ');
   disp('  1  --> (year, month, day) to (GPS week, GPS roll number, day of week)');
   disp('  2  --> (GPS week, day of week, GPS roll number) to ')
   disp('                      (day of week, day, month, year)');
   disp('  3  --> (day of week, hour, minute, second) to time of week');
   disp('  4  --> time of week to (day of week, hour, minute, second)');
   disp(' ');
   select = input('Make the selection -->  ');
   disp(' ');

   if (select == 1) 

%  Transformation from (year, month, day) to (GPS week, GPS roll number)

fprintf(f2,'***************************************************************\n\n');
year  = input('Specify the year, e.g. 1999, --> ');
month = input('Specify the month, e.g. 1,   --> ');
day   = input('Specify the day, e.g. 28,    --> ');
tdate   = datenum(year,month,day);
gpsweek = mod(floor((tdate-trefgps)/7),1024);
gpsroll = floor(floor((tdate-trefgps)/7)/1024);
dow = (tdate - trefgps) - (gpsroll*1024 + gpsweek)*7;
disp('  ');
if  (f2 ~= 1)
   fprintf(f2,'year =  %4.0f, month = %2.0f, day = %2.0f\n\n', year,month,day);
end   
fprintf(f2,'gpsweeek = %4.0f, gps roll number = %3.0f, day of week = %3.0f\n\n',...
            gpsweek, gpsroll,dow);
fprintf(f2,'***************************************************************\n\n');

   elseif (select == 2)                     

%  Transformation from (GPS week, day of week, GPS roll number) to 
%  (day of week, day, month, year)

fprintf(f2,'***************************************************************\n\n');
gpsweek  = input('Specify the gps week (0 to 1023), e.g. 949,     --> ');
dow      = input('Specify day of week (0 to 6), e.g. 2,           --> ');
gpsroll  = input('Specify the gps roll number (0 to ...), e.g. 1, --> ');
temp  = trefgps + (gpsweek + 1024*gpsroll)*7 + dow;
date1 = datestr(temp,1);
date2 = datestr(temp,8);
disp('  ');
if  (f2 ~= 1)
   fprintf(f2,'gpsweeek = %4.0f, day-of-week = %2.0f, gps roll number = %3.0f\n\n',...
               gpsweek, dow, gpsroll);
end
fprintf(f2,'date = %s \n\n', [date2  '   '  date1]);         
fprintf(f2,'***************************************************************\n\n');

   elseif (select == 3)

%  Transformation from (day of week, hour, minute, second) to time-of-week

fprintf(f2,'***************************************************************\n\n');
dow  = input('Specify day of week (0 to 6), e.g. 2, --> ');
hour = input('Specify hour (0 to 23), e.g. 5,       --> ');
min  = input('Specify minute (0 to 59), e.g. 34,    --> ');
sec  = input('Specify second (0 to 60), e.g. 46,    --> ');
tow  = (dow*24 + hour)*3600 + min*60 + sec;
disp('  ');
if  (f2 ~= 1)
   fprintf(f2,'day of week = %3.0f, hour = %2.0f, min = %2.0f, sec = %2.0f\n\n',...
               dow, hour, min, sec);
end
fprintf(f2,'time of week = %6.0f \n\n', tow);
fprintf(f2,'***************************************************************\n\n');

   elseif (select == 4)  
                   
%  Transformation from time-of-week to (day of week, hour, minute, second) 

fprintf(f2,'***************************************************************\n\n');
tow  = input('Specify time of week (0 to 604800), e.g. 43200,  --> ');
dow  = mod(floor(tow/86400),6);
hour = mod(floor(tow/3600),24);
min  = mod(floor(tow/60),60);
sec  = mod(tow,60);
disp('  ');
if  (f2 ~= 1)
   fprintf(f2,'time of week = %6.0f \n\n', tow);
end   
fprintf(f2,'day of week = %3.0f, hour = %2.0f, min = %2.0f, sec = %2.0f\n\n',...
            dow, hour, min, sec);
fprintf(f2,'***************************************************************\n\n');

   else

      disp('Selection is not in the designated range');
   
   end

%  Select another computation, if desired

   answer = input('Do you want another computation? (y/n)[n] --> ','s');
   disp(' ');

end

disp('End of the program  XGPSTIME');
disp(' ');