## Appendix 1  
Here is shown how to derive the onboard yaw angle and his effects on the interferometer swath. Let's first define the frames in which we are working:  
- the local orbital frame ROL(t), with :  
\(\bullet\)\(\ Z_{\rm ROL}\) : in the direction Earth/Satellite, towards the Earth( - yaw axis)  
\(\bullet\)\(\ Y_{\rm ROL}\) : orthogonal to the orbital plane, opposite to the angular momentum of the satellite ( - pitch axis)  
\(\bullet\)\(\ X_{\rm ROL}\) : to complete the trihedron (roll axis)  
- the satellite frame SAT(t), in rotation around-\(Z_{\rm ROL}\) with an angle \(\Psi\)In order to optimize the solar panels orientation, the platform first has to be oriented for -Xtarget to be directed toward the Sun. The following spherical triangle illustrates this:  
The formula related to spherical triangles leads to:  
\[\cos\!\left(\frac{\pi}{2}-\left[-\
u\right]\right)=\cot\!\left(\frac{\pi}{2}- \beta\right)\cot\!\left(\frac{\pi}{2}-\Psi\right)\]  
then:  
\[\tan\!\left(\Psi\right)=-\frac{\tan\!\left(\beta\right)}{\sin\!\left(\
u\right)}\]  
There still remains a \(\pi\) uncertainty on the knowledge of the yaw angle. Another condition is going to help erase this ambiguity. -Xtarget has to face the sun, therefore we have:  
\[-\overrightarrow{X_{{}_{\text{targ}et}}}\overrightarrow{V_{{}_{\text{SOL}}} }\geq 0\]  
In the local orbital frame, we can write:  
\[\overrightarrow{X_{{}_{\text{targ}et}}} =\cos\!\left(\Psi\right)\!\overrightarrow{X_{{}_{\text{ROL}}}}- \sin\!\left(\Psi\right)\!\overrightarrow{Y_{{}_{\text{ROL}}}}\] \[\overrightarrow{\text{V}_{{}_{\text{SOL}}}} =\cos\!\left(\beta\right)\!\sin\!\left(\
u\right)\! \overrightarrow{X_{{}_{\text{ROL}}}}-\sin\!\left(-\beta\right)\! \overrightarrow{Y_{{}_{\text{ROL}}}}-\cos\!\left(\beta\right)\!\cos\!\left( \
u\right)\!\overrightarrow{Z_{{}_{\text{ROL}}}}\]  
which becomes :  
\[\cos\!\left(\Psi\right)\!\cos\!\left(\beta\right)\!\sin\!\left(\
u \right)-\sin\!\left(\Psi\right)\!\sin\!\left(\beta\right)\!\geq 0\] \[\cos\!\left(\Psi\right)\!\sin\!\left(\
u\right)\!\left[\cos\! \left(\beta\right)+\frac{\sin^{{}^{2}}\!\left(\beta\right)}{\sin^{{}^{2}}\! \left(\
u\right)}\frac{1}{\cos\!\left(\beta\right)}\right]\!\geq 0\]  
then, knowing that \(\beta\) remains between -90\({}^{\circ}\) et +90\({}^{\circ}\) :  
\[\cos\!\left(\Psi\right)\!\sin\!\left(\
u\right)\!\geq 0\]  
Finally, a last condition needs to be taken into account: when \(\beta\) is less than 15\({}^{\circ}\) in absolute value, there is no yaw steering. Computing all that gives the plot on Figure 8 (a). The effects on the swath can then easily be calculated as followed (see Figure 25):  
**Figure 25.** Effects of the yaw angle on the interferometric swath. \[\alpha=\frac{\pi}{2}-\psi\]  
\[\tan\!\left(\Psi\right)=-\frac{\tan\!\left(\beta\right)}{\sin\!\left(\
u\right)}\]0  
\[\tan\!\left(\Psi\right)=-\frac{\tan\!\left(\beta\right)}{\sin\!\left(\
u\right)}\]1  
**Appendix 2** \begin{tabular}{|c|c|} \hline B & Interferometric baseline \\ \hline \(\theta\) & View angle \\ \hline r / R & Range \\ \hline X & Position in the swath \\ \hline h & Height above the tangent plane at nadir \\ \hline \(\alpha\) & Roll angle \\ \hline H & Altitude of the satellite \\ \hline \(\Phi\) & Interferometric phase \\ \hline k & Wavenumber/Boltzman constant \\ \hline R\({}_{\rm{o}}\)/R\({}_{\rm{a}}\) & Earth radius nadir/Earth radius target \\ \hline h\({}_{\rm{real}}\) & Height in the local frame above the ellipsoid \\ \hline X\({}_{\rm{real}}\) & Target position in the local frame \\ \hline A & Ellipsoid arc between nadir and target \\ \hline \(\gamma\) & Correlation between the two channels \\ \hline N & Number of looks \\ \hline \end{tabular}   
**Figure 25.** Effects of the yaw angle on the interferometric swath.