# Fast Deployment of a UWB-Based IPS for Emergency Response Operations
## 5 Performance Evaluation
### Tag Tracking  
The UWB-based IPS was also tested on a mobile object. The tracking of an FR during an ER operation was simulated according to the guidelines provided by FRs from the City of Barcelona's Fire Department. Specifically, a user carried a tag placed on a helmet while performing a predefined path throughout the target building. The speed \(v\) at which the user walked was assumed to be slow (i.e., \(v<1\) m/s), as it was intended to reproduce the movement of an FR during an ER operation, where heavy equipment may be carried and caution is necessary when approaching or being inside a disaster-affected area. Different paths were designed with the aim of covering the different rooms of the building and evaluate the performance of the tracking system in all those spaces. Again, Table 4 compiles the rest of the configuration parameters. Figure 13 shows the expected and the computed tracking of \(pathA\) on the ground floor of the target building. This path simulates the movement performed by an FR entering the building, looking for victims in that floor, and exiting the building. In addition, it passes through six well-known reference points. As can be observed, the path followed by the user is reproduced with high faithfulness, even in the narrow aisles of the \(north\) side of the building. In general, the estimated positions are rarely placed on obstacles or far from the actual aisle. Figure 12: Static localization accuracy and precision. Similarly, _pathB_ simulates the path followed by a FR looking for victims after having accessed the first floor through the stairs (see Figure 14). All reference points from this floor were also included in the path. While it is true that no aisles are available to assess the accuracy, the path followed between two consecutive reference positions is always straight except for the \(puntl\to puntl\) section. Specifically, some deviation is detected around \(puntl\), where the estimated positions are roughly 2 m closer to the wall than they should be. As for the \(puntQ\to puntP\) section, it was explicitly performed in two different straight movements due to the presence of some objects on the floor. Figure 14: Tracking map of _pathB_ on the first floor. (**a**) Executed path. (**b**) Computed tracking. Figure 13: Tracking map of _pathA_ on the ground floor. (**a**) Executed path. (**b**) Computed tracking. Lastly, the positioning system was also evaluated outdoors in _pathC_. More explicitly, a user walked through the building's external shape in a counterclockwise direction, as shown in Figure 15, with the tag always confined inside the outer polygon created by the deployed anchors. Therefore, this test proves the continuity of the proposed UWB-based IPS while transitioning to a potentially available absolute positioning system (e.g., based on GPS technology) when the FR goes into the open air. The shape of the building can be easily inferred from the obtained tracking, with two remarkable exceptions highlighted in yellow color in Figure 15b: (1) an erroneous estimated position that places the tag closer to anchor _#8828_ than expected and (2) an area with some position divergence between anchors _#5 BA0_ and _#3 EB_. (The area between anchors _#2 CDB_ and _#1A25_ was not accessible during the test execution.) A deeper analysis of the obtained rangings may explain the bad performance of the positioning system in the two aforementioned cases:  
1. In the first case, the tag has computed rangings from all anchors except for _#5 BA0_. In addition, the ranging values from anchors on the opposite side of the building (i.e., _#1A25_ and _#3 EB_) are larger than the real distance, moving the final position estimation far from the building's shape. 2. Similarly, in the second case there is an important lack of rangings coming from anchors on the opposite side of the building (i.e., _#2 CDB_, _#8828_, and, to a lesser extent, _#1A40_).