# Optical Flow Odometry with Panoramic Image Based on Spherical Congruence Projection
## 4 Experiments and Discussion
### Comparative Experimental Results
LF-VIO exhibited similar instability at about 31s, reaching an RPEt of 8.91%. In contrast, the proposed SCP method maintained stable performance across these conditions, with RPEt values of 0.73%, 1.08%, and 1.02% at 31s, 34s, and 36s, respectively. This resilience may be attributed to SCP's spherical geometric topological constraints, which preserve global feature associations even when partial image regions suffer from tracking failures. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**VIO-Method** & **Index** & \begin{tabular}{c} **RS01** \\ **CI** \\ \end{tabular} & \begin{tabular}{c} **RS02** \\ **CI** \\ \end{tabular} & \begin{tabular}{c} **RS03** \\ **CI** \\ \end{tabular} & \begin{tabular}{c} **RS04** \\ **CI** \\ \end{tabular} & \begin{tabular}{c} **RS05** \\ **CI** \\ \end{tabular} & \begin{tabular}{c} **RS06** \\ **CI** \\ \end{tabular} \\ \hline \multirow{3}{*}{\begin{tabular}{c} SCP \\ -VIO \\ \end{tabular} } & RPEt (\%) & [1.676,2.051] & [1.635,2.028] & [1.852,2.230] & [2.144,2.543] & [1.788,2.117] & [2.651,3.207] \\  & RPEt (deg/m) & [1.930,2.486] & [2.305,2.991] & [1.981,2.510] & [2.290,2.866] & [2.139,2.749] & [2.593,3.276] \\  & ATE (m) & [0.149,0.157] & [0.092,0.099] & [0.133,0.145] & [0.126,0.137] & [0.159,0.168] & [0.289,0.314] \\ \hline \multirow{3}{*}{\begin{tabular}{c} LF \\ -VIO \\ \end{tabular} } & RPEt (\%) & [2.145,2.618] & [2.334,2.910] & [2.299,2.780] & [2.376,2.842] & [2.222,2.669] & [2.698,3.209] \\  & RPEt (deg/m) & [2.003,2.581] & [2.477,3.188] & [2.517,3.227] & [2.626,3.287] & [2.282,2.913] & [2.609,3.293] \\  & ATE (m) & [0.185,0.197] & [0.179,0.191] & [0.145,0.154] & [0.151,0.160] & [0.184,0.198] & [0.164,0.174] \\ \hline \multirow{3}{*}{\begin{tabular}{c} VINS \\ -MONO \\ \end{tabular} } & RPEt (\%) & [2.508,3.008] & [2.362,2.920] & [2.302,2.815] & [2.253,2.707] & [2.139,2.614] & [2.418,2.917] \\  & RPEt (deg/m) & [2.012,2.591] & [2.555,3.292] & [2.425,3.111] & [2.402,3.038] & [2.444,3.141] & [2.649,3.336] \\  & ATE (m) & [0.229,0.249] & [0.195,0.208] & [0.142,0.154] & [0.123,0.130] & [0.115,0.122] & [0.139,0.153] \\ \hline \multirow{3}{*}{\begin{tabular}{c} VIO Method \\ \end{tabular} } & Index & RS07 & RS08 & RS09 & RS10 & RS11 & RS12 \\  & & CI & CI & CI & CI & CI & CI \\ \hline \multirow{3}{*}{\begin{tabular}{c} SPC \\ -VIO \\ \end{tabular} } & RPEt (\%) & [2.092,2.592] & [2.442,2.944] & [2.088,2.506] & [2.389,2.945] & [2.691,3.306] & [2.837,3.472] \\  & RPEt (deg/m) & [2.842,3.725] & [2.009,3.759] & [2.473,3.143] & [3.244,4.227] & [1.349,2.370] & [0.755,1.139] \\  & ATE (m) & [0.127,0.248] & [0.182,0.196] & [0.152,0.164] & [0.193,0.209] & [0.220,0.236] & [0.284,0.302] \\ \hline \multirow{3}{*}{\
\begin{tabular}{c} LF \\ -VIO \\ \end{tabular} } & RPEt (\%) & [3.364,4.106] & [0.283,0.339] & [2.447,2.970] & [3.179,3.894] & [3.185,3.939] & [2.930,3.592] \\  & RPEt (deg/m) & [2.617,3.391] & [2.893,3.586] & [2.803,3.585] & [3.369,4.381] & [3.222,4.196] & [1.787,2.176] \\  & ATE (m) & [0.366,0.403] & [0.186,0.197] & [0.164,0.172] & [0.149,0.162] & [0.213,0.228] & [0.274,0.292] \\ \hline \multirow{3}{*}{
\begin{tabular}{c} VIN \\ -MONO \\ \end{tabular} } & RPEt (\%) & [2.637,3.289] & [2.883,3.466] & [2.226,2.691] & [3.165,3.922] & [3.046,3.774] & [3.074,3.767] \\  & RPEt (deg/m) & [2.727,3.531] & [2.972,3.680] & [2.200,2.749] & [3.320,4.297] & [3.205,4.154] & [1.837,2.230] \\ \cline{1-1}  & ATE (m) & [0.189,0.211] & [0.269,0.292] & [0.198,0.214] & [0.131,0.141] & [0.180,0.194] & [0.231,0.347] \\ \hline \hline \end{tabular}
\end{table} 
Table 4: The confidence interval of RMSE on SCP-Image dataset. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**VIO-Method** & **Gauss** & \begin{tabular}{c} **\(\sigma\) = 10** \\ **RMSE** \\ \end{tabular}  & \begin{tabular}{c} **\(\sigma\) = 25** \\ **Std** \\ \end{tabular}  & \begin{tabular}{c} **\(\sigma\) = 50** \\ **RMSE** \\ \end{tabular}  & \begin{tabular}{c} **\(\sigma\) = 50** \\ **RMSE** \\ \end{tabular}  \\ \hline \multirow{3}{*}{ \begin{tabular}{c} SCP-VIO \\ \end{tabular}