Table 2 Different estimable parameters in the code-plus-phase ionosphere-float, ionosphere-weighted, and ionosphere-fixed models
From: PPP–RTK functional models formulated with undifferenced and uncombined GNSS observations
Parameter | Estimable form | ||
|---|---|---|---|
Ionosphere-float | Ionosphere-weighted | Ionosphere-fixed | |
Satellite clock | \({\text{d}}\tilde{t}^{s} = {\text{d}}\overline{t}^{s} - {\text{d}}\overline{t}_{1}\) | \({\text{d}}\tilde{\tilde{t}}^{s} = {\text{d}}\overline{t}^{s} - {\text{d}}\overline{t}_{1} - m_{1}^{s} \tilde{\tau }_{1}\) | \({\text{d}}\overline{\overline{t}}^{s} = {\text{d}}\overline{t}^{s} - {\text{d}}\overline{t}_{1} - \tau^{s}\) |
BR-DCB | None | \(\tilde{d}_{{r,{\rm GF}}} = d_{{r,{\rm GF}}} - d_{{1,{\rm GF}}} \,\) | \(\tilde{d}_{{r,{\rm GF}}} = d_{{r,{\rm GF}}} - d_{{1,{\rm GF}}} \,\) |
Receiver phase bias | \(\begin{gathered} \tilde{\delta }_{r,j} = \delta_{1r,j} - d_{{1r,{\rm IF}}} \hfill \\ + u_{j} d_{{1r,{\rm GF}}} + \lambda_{j} z_{1r,j}^{1} \hfill \\ \end{gathered}\) | \(\tilde{\tilde{\delta }}_{r,j} = \delta_{1r,j} - d_{{1r,{\rm IF}}} + \lambda_{j} z_{1r,j}^{1}\) | \(\tilde{\tilde{\delta }}_{r,j} = \delta_{1r,j} - d_{{1r,{\rm IF}}} + \lambda_{j} z_{1r,j}^{1}\) |