Reading blocks of data

13 03 12 00 00  0.0000000  0  7 G05 G16 G21 G25 G29 G30 G31*
23178802.640   121805444.22508      -722.816    23178801.180    94913344.40346
    -563.238
23899154.020   125590912.38807      3334.078    23899151.480    97863037.80844
    2597.980

I have this ASCII format file with data shown above. I want to extract, with a function, from this block the following: The satellite number and its coresponding data.

First satellite (G05) corresponds to 1'st and 2'nd line of data and so on for the rest of the satellites(G16, G21, G25 etc.)

As output of function, I'm looking forward to obtain a 7 x n matrix, where n=number of satellites:

 e.g: Observation (7xn) =[     5                  16             n             
                         23178802.640        23899154.020        --- 
                         121805444.22508     125590912.38807     ---
                         -722.816            3334.078            ---
                         23178801.180        23899151.480        ---
                         94913344.40346      97863037.80844      ---
                         -563.238            2597.980            ---]

Any advices or ideas on how I should start would be very much appreciated.

Note: The data blocks are from an RINEX OBSERVATION file.

Answer 1

[dpb]

13 03 12 00 00  0.0000000  0  7 G05 G16 G21 G25 G29 G30 G31*

fid=fopen('filename.txt','r');   % open file
l=fgetl(fid);                    % get header line to parse
[n,~,~,nxt]=sscanf(l,[repmat('%*f',1,7) '%d']);  % find n, number of sat's, next place in string
fmt=[repmat('G%d ',1,n-1) 'G%d*'];        % build format string for the sat's
s=sscanf(l(nxt:end),fmt);                 % read sat no's
d=cell2mat(textscan(fid),repmat('%f',1,6))).';  % read and reshape data