PPPH is a multi-system GNSS precision positioning and analysis software based on MATLAB written by Berkay Bahadur. It not only supports the graphical interface (the official documents claim that matlab2016a and above are required, I did not succeed in 2016a, I use matlab2018a directly), and it can also be run using the command line, which is very convenient. , Some similar bugs were discovered during the recent debugging process, resulting in unsatisfactory accuracy of the calculated sample data. The bugs are listed below, I hope you can criticize and correct them.
In a data_hand.m file:
the track file name is wrong one day after line 10
Original code:
if ~isempty(files.orbitb) && ~isempty(files.orbitb)
After modification:
if ~isempty(files.orbitb) && ~isempty(files.orbita)
2. In the cs_detect.m file:
line 65, the wavelength of the second frequency is wrong during GF combined cycle slip detection
Original code: A = [1 -1;wavl(k,1) -wavl(k,1)];
after modification: A = [1 -1;wavl(k,1) -wavl(k,2)]; In the
three outlier.m file:
when the cycle slip is fitted by the second-order polynomial in line 30, the number of fitting points is less than 3 and the
following code is added:
if(ran<3)
data.obs.st(st:fn,k) = 0;
break;
end
Line 36
: The redundancy error when calculating the unit weight error Original code:
rmse = sqrt(sum(V.^2)/ran);
After modification:
rmse = sqrt(sum(V.^2)/(ran-3));
4. In the nmodel.m file:
Line 151: Wavelength index error
Original code:
model(t,20) = ((wind_up(r_xyz,s_xyz,sun_xyz,prev))/2/pi)*wavl(k,1);
After modification:
model(t,20) = ((wind_up(r_xyz,s_xyz,sun_xyz,prev))/2/pi)*wavl(k,2);
5. In
the 9th line of the sat_apc.m file, when calculating the satellite antenna phase center correction, the cosine j formula in the y direction of the conversion matrix is incorrect.
Original code:
j = cross(k,e);
After modification:
j = cross(k,e)./norm(cross(k,e));
The modified software uses the single GPS static mode to process the sample data (ISTA00TUR_R_20171910000_01D_30S_MO.17o). The results are compared with the IGS sky solution coordinates.
NEU direction error statistics
after convergence : the final epoch coordinate after convergence is different from the known IGS coordinate, the three XYZ directions deviations are:
X: 0.8mm Y: -0.2mm Z: -3.6mm