GPS Software Receivers - Fundamentals of Global Positioning System Receivers: A Software Approach - page 215

%p95.m DECODE3.M decode navigation data in subfram 3 into
ephermeris data

clear angmat navd rymkmat
load d:

\ gps \ big data \ srvy8310;

angmat=ang;
ptnumat=transpt;
rymkmat=fintime;

[st navd]=navdat(angmat); %*find naviga data (20ms) & first
angle transition
[points, navdata]=matsubf(navd); %*find start pt of subfrm 3
pro01s

nsat=length(points);
for m=1:nsat;
cic(m)=comp2dec(navdata(m,points(m)-1+76:-1:points(m)-
1+61),-29);

comega1=navdata(m,points(m)-1+84:-1:points(m)-1+77);
comega2=navdata(m,points(m)-1+114:-1:points(m)-1+91);
comega3=[comega2 comega1];
comega0(m)=comp2dec(comega3,-31)*pi;
clear comega1 comega2 comega3;
cis(m)=comp2dec(navdata(m,points(m)-1+136:-1:points(m)-
1+121),-29);

i01=navdata(m,points(m)-1+144:-1:points(m)-1+137);
i02=navdata(m,points(m)-1+174:-1:points(m)-1+151);
i03=[i02 i01];
i0(m)=comp2dec(i03,-31)*pi;
clear i01 i02 i03;
crc(m)=comp2dec(navdata(m,points(m)-1+196:-1:points(m)-
1+181),-5);

omega1=navdata(m,points(m)-1+204:-1:points(m)-1+197);
omega2=navdata(m,points(m)-1+234:-1:points(m)-1+211);
omega3=[omega2 omega1];
omega(m)=comp2dec(omega3,-31)*pi;
clear omega1 omega2 omega3;
comegadot(m)=comp2dec(navdata(m,points(m)-1+264:-
1:points(m)-1+241),-43)*pi;
iode3(m,:)=navdata(m,points(m)-1+271:points(m)-1+278);
idot(m)=comp2dec(navdata(m,points(m)-1+292:-1:points(m)-
1+279),-43)*pi;
end