Conclusion

A number of important features have been identified in all measurement series. These are summarized here.

Inaccuracy increases with distance

All measurement series showed that a correlation between the measuring distance and the angular accuracy is difficult to detect. Perhaps a more precise statement could be made for example at a distance of 30m. In general, however, it can be said that with a constant inaccuracy the scattering distance of the measuring points increases with increasing distance. This is simple trigonometry and cannot be avoided.

Alignment of the antenna array

The alignment of the antenna arrays has a relation to the measurement accuracy. Measurements between ±20° and ±60° are the most accurate, whereas measurements around 0° are the least accurate. For measurements around 0° both antenna pairs of the antenna array are evaluated and the system decides for the better result. Since this is not always clear, sometimes wrong decisions can be made. Here the increasing inaccuracy plays a role, which can be detected from ±60°.

Use of multiple antenna arrays

Since the antenna arrays are most accurate at ±45°, and since the angular inaccuracy increases with increasing distance, the dispersion of the measurement position also increases, antenna arrays should be optimally distributed over the surface to be measured. With several antenna arrays, the individual ones can be aligned so that the factor distance and alignment is optimal at ±45°. These factors can also be taken into account in the evaluation and better placed antenna arrays can be weighted more heavily.

Accuracy of the measurements

Measurements at a distance of 2m and an optimal alignment of ±45° were carried out with a positional accuracy of 30cm. If the distance changes to 4m it is still approx. 1m, at 6m distance still approx. 2.5m and at 8m distance still approx. 6m.