## 3 Experiments, Results and Discussion
### Kinematic Surveys Under Adverse Conditions  
The positioning procedures and the equipment were both tested in different kinematic surveys and under different conditions. Their outlines are depicted in Figure 2 (B). Environment (d) was a mixed condition environment. The start and the end of the survey represented relatively normal conditions, \begin{table}
\begin{tabular}{c c c c c c c} \hline  & \multicolumn{3}{c}{**C1**} & \multicolumn{3}{c}{**custom**} \\  & **N** & **E** & **h** & **N** & **E** & **h** \\ \hline min (m) & \(-175.8\) & \(-29.3\) & \(-124.0\) & \(-14.5\) & \(-5.4\) & \(12.9\) \\ max (m) & \(49.1\) & \(55.5\) & \(206.2\) & \(29.0\) & \(21.4\) & \(32.4\) \\ mean (m) & \(-34.0\) & \(17.0\) & \(36.4\) & \(3.5\) & \(9.3\) & \(22.7\) \\ st.dev. (m) & \(53.2\) & \(13.3\) & \(84.8\) & \(10.5\) & \(6.0\) & \(4.8\) \\ \hline \end{tabular}
\end{table} 
Table 3: Statistics of the worst and best indoor solutions. Figure 5: The best and worst indoor solutions: (i) autonomous C1 positioning; (ii) custom positioning procedure with C1&D1, plus ionosphere and troposphere models. however, in the middle, the survey stops underneath the overhanging roof turret for approximately 30 seconds. The whole survey takes 60 seconds. Some of the results of the developed solutions are shown in Figure 6. The black line represents the approximate trajectory and the blue outline depicts part of the overhanging roof. The first and the last determined positions are marked with larger dots. The positions are shown in the projection plane. Plotted units are in metres. Once again, code-only positioning yields major position errors--see plot (i). The results are considerably better using the custom positioning procedure, when either the initial position is known (ii) or the ionosphere and the troposphere models are used (iii). As a comparison, the internal position is also shown--see plot (iv). The positions remain close to one another, although the cluster of points ought to be under the overhanging roof. **Figure 6.** Solutions in a mixed-condition environment (d): **(i)** autonomous C1 positioning; **(ii)** custom positioning procedure with C1&D1, initial position presumed known; **(iii)** custom positioning procedure with C1&D1, plus ionosphere and troposphere models; **(iv)** internal positioning of the receiver. Units are in meters. The results of the cDGPS of the same survey are shown in Figure 7.Whenever possible, the cDGPS was performed (green dots).When this was not possible, the custom autonomous positioning was used (red dots).The recalculation of the \"no cDGPS\" positions was also applied (blue dots). Figure 8 displays some of the characteristic solutions of environment (e). Most of the survey takes place under adverse conditions beneath the roof gutter. The survey path is denoted by the dashed line. The blue outline depicts the overhanging roof. The first plot (i) demonstrates why the Doppler-only solution is not the best option. Whilst the Doppler positioning performs particularly well under normal conditions this is not the case under adverse conditions. The path scale appears to be slightly reduced. Plot (ii) illustrates the results of Doppler smoothing of code observations using the Hatch filter. The procedure causes major deviations from the actual path. In this particular case, the best solution is the custom procedure of C1 and D1 with the additional application of the elevation angle weighting and the SNR weighting. Again, the results of the internal processing are also shown as a comparison. Figure 7: Conditional DGPS in environment (d): (\(\bullet\)) cDGPS positions; (\(\bullet\)) custom positioning procedure with C1&D1; (\(\bullet\)) recalculated positions.Units are in meters. The results of the cDGPS of the same survey are shown in Figure 9.The cDGPS is active at the start and at the end of the survey as well as during5 epochs in between (see green dots).This solution represents the best of all outcomes, especially when the recalculated positions are considered (blue dots instead of red dots).