Unexpected result in estimating receiver and satellite DCB from GNSS using Least squares .

My goal is to estimated receiver and satellite DCB from GNSS observation using using Least squares and validate against the standard DCB from Centre from orbit determination in Europe (CODE). However, after i run the main script main_dcb_estimation.m i got unexpected results in the estimates of the receiver and satellite DCB.

Please note that i am not estimating VTEC along side the DCBs. Am using the VTEC from CODE ionex file. Also note that i am just trying out the script over one station ABUZ and one DOY. Later i will extend the program to multple GNSS receiver and multiple DOY.

I have tried to fix the bug but to no avail. I really need help fixing this bug

the model am trying to implement is described in the attached pdf file 1_Dual_frequency.pdf

[Torsten]

We don't have the LaTex converter switched on - could you adapt the problem formulation pdf to a readable form ?

[Solomon]

Thank you for your feedback and question. I have now attached an updated file GNSS_Dual_Freque.pdf that contains model formulation that is not in LaTex format. Thank you for your anticipated support

[Torsten]

Sorry, but I have too little technical background to understand your code.

The only thing I can tell you is that the MATLAB function to do linear least squares under the linear rank constraint usually is "lsqlin".