## 4 Data Products and Processing
### Accessing and Processing of the Data Product
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Group** & **Variable** & **Dim** & **Description** & **Unit** & **Symbol** \\ \hline \multirow{4}{*}{d\_Code\_Phase} & \multirow{2}{*}{time} & Code phase of the local code replica for the direct signal, estimated from the code tracking loop and interpolated at \(t_{0}\) & Chip & \(\Phi_{\text{code}}^{\text{d}}\) in (3) \\ \hline \multirow{4}{*}{d\_Doppler} & \multirow{2}{*}{time} & Carrier Doppler of the local carrier replica for the direct signal, estimated from the carrier tracking loop and interpolated at \(t_{0}\) & Hz & \(f_{\text{carr}}^{\text{d}}\) in (3) \\ \hline \multirow{4}{*}{d\_Phase} & \multirow{2}{*}{time} & Carrier phase of the local carrier replica for the direct signal, estimated from the carrier tracking loop and interpolated at \(t_{0}\) & Cycle & \(\phi_{\text{carr}}^{\text{d}}\) in (3) \\ \hline \multirow{4}{*}{bistatic\_delay} & \multirow{2}{*}{time} & Additional range delay of the reflected signal with respect to the direct one, interpolated at \(t_{0}\) & Meter & \(\delta\rho_{\text{OL}}^{\text{dr}}\) in (2) \\ \hline \multirow{4}{*}{r\_Code\_Phase} & \multirow{2}{*}{time} & Code phase of the reflected signal, which is interpolated at \(t_{0}\) and applied to the local code replica generation & Chip & \(\Phi_{\text{code}}^{\text{d}}\) in (1) and (3) \\ \hline \multirow{4}{*}{r\_Doppler} & \multirow{2}{*}{time} & Carrier Doppler of the reflected signal, which is interpolated at \(t_{0}\) and applied to the local carrier replica generation & Hz & \(f_{\text{carr}}^{\text{r}}\) in (1) and (3) \\ \hline \multirow{4}{*}{r\_Phase} & \multirow{2}{*}{time} & Carrier phase of the reflected signal, which is interpolated at \(t_{0}\) and applied to the local carrier replica generation & Cycle & \(\Phi_{\text{code}}^{\text{d}}\) in (1) and (3) \\ \hline \multirow{4}{*}{wf\_up\_i} & \multirow{2}{*}{time, lag} & Complex waveform for the direct signal (Inphase) & - & - \\ \hline \multirow{4}{*}{wf\_up\_q} & \multirow{2}{*}{time, lag} & Complex waveform for the direct signal (Quadra-ture) & - & - \\ \hline \multirow{4}{*}{wf\_dw\_i} & \multirow{2}{*}{time, lag} & Complex waveform for the reflected signal (Inphase) & - & real\([z^{r}]\)) \\ \cline{2-2} \cline{4-5}  & \multirow{2}{*}{wf\_dw\_q} & \multirow{2}{*}{time, lag} & Complex waveform for the reflected signal (Quadra-ture) & - & imag\([z^{r}]\)) \\ \hline \multirow{4}{*}{wf\_up\_i} & \multirow{2}{*}{MetaTime} & Reference time of the metadata & GPS & \multirow{2}{*}{\(t_{\text{M}}\) in (2)} \\ \cline{2-2} \cline{4-5}  & x\_rcv, y\_rcv, z\_rcv & time & Position of the receiver in WGS-84 coordinate at \(t_{\text{M}}\) & Meter & \(\mathbf{R}(t_{\text{M}})\) in (2) \\ \cline{2-2} \cline{4-5}  & x\_tx, y\_tx, z\_tx & time & Position of the transmitter in WGS-84 coordinate at \(t_{\text{M}}\) & Meter & \(\mathbf{T}(t_{\text{M}})\) in (2) \\ \cline{2-2} \cline{4-5}  & x\_sp, y\_sp, z\_sp & time & Position of the specular point in WGS-84 coordinate at \(t_{\text{M}}\) & Meter & \(\mathbf{S}(t_{\text{M}})\) in (2) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._Download_cWF_File_List: In addition to the complex waveform netCDF files, the lists of the product tracks are also available at the server. This function is to download the up-to-date lists of the complex waveform products, which include the basic information of the raw IF tracks, such as the raw IF data ID, the data collection time, the PRN of the GNSS transmitter, the SNR of the direct and reflected signals, and the geolocation of the specular point. - _Find_RawIF_Track: With the basic information of all available tracks, this function is to search complex waveform tracks by time and geographic location, which returns a text file including a list of the complex waveform files with the specular point crossing the target area, i.e., a rectangle area defined by the maximum/minimum latitudes and longitudes. - _Download_cWF_File: This function is to download a local copy of a complex waveform file from the data server.