**5. Concluding remarks**

appearance based. The last ones are widely used, being the local face descriptors those which

In biometric forensic studies, a common disadvantage of gaming sensors and visible methods is their vulnerability to spoofing (synthetic forged version of the biometric original). This weakness is being overcome by thermographic cameras. The new challenges try to solve the integration of different electromagnetic range images, for example thermal with visible,

Indoor mobile mapping systems could be defined as a complex set of sensors that allows spatial data acquisition in movement. This is especially useful in forensic indoor scenarios when some environmental conditions become dangerous for humans (chemical risks, danger of collapse, etc.) or simply in those places really complex where a lot of laser or photographic stations would be required [32]. The set of sensors is composed by two groups of electronics devices working together on a self‐moved vehicle [33]. On the one hand, navigation instruments are in charge of the guidance of the vehicle, providing an automatic motion through a planned route. On the other hand, the role of geomatic sensors, such a digital cameras or laser scanners, is the acquisition of spatial data (images and point clouds), as described in previous sections. Both geomatic and navigation sensors are controlled by a microprocessor, so that measure‐ ments are done simultaneously. Furthermore, each set of spatial data is associated to a time stamp which links it with the positioning settings of the mobile unit in every instant [34].

Navigation devices could integrate high‐precision GNSS, advanced inertial technology (three axis accelerometers and gyroscopes), magnetometers and pressure sensors to calculate orientations and heights. The indoor georeferencing is done by using measures from GNSS outdoors. The inertial measurement unit provides uninterrupted data of the true position, roll,

Data acquisition is performed when the vehicle is in motion following a planned route whose purpose is to cover all the parts of the scene. There are two possibilities in the route configu‐ ration: making a round trip, or a back and forth displacement. The strategy selected will come as a consequence of the ground characteristics in the area inspected, since obstacles should be avoided in order to have a continuous path. If the last option is not possible, data will have to be acquired in different sequences, and then a registration procedure will put all the sequences in the same coordinate system, considering that there are overlapping areas within consecutive sequences. When data acquisition is finished, the absolute position of each single point is calculated from the data of the trajectory of the navigation unit, making it possible to obtain a

The time needed for indoor mobile mapping systems during data acquisition is equal to the time that a person needs to walk through the area of interest; with the noticeable time reduction

In forensic engineering, indoor mapping systems (**Figure 11**) stand out for their suitability for the acquisition of big and complex indoor scenes, as they perform automatically multiple

have better performance in non‐controlled environments.

20 Forensic Analysis - From Death to Justice

dealing with a problem known as multimodal matching [31].

**4.3. Indoor mobile mapping systems and Forensic**

pitch and yaw of the system when moving indoors [35].

complete 3D point cloud of the inspection area.

regarding other systems and an important cost decrease [36].

This chapter has described the close connection between geomatics and forensics. We analysed the main areas in which geomatics can be useful for forensic analysis, and detailed the main requirements that spatial information must fulfil to meet the needs of forensic studies. There has been a brief and understandable overview to the main geomatic technologies currently used, describing their fundamentals and emphasizing its usability in forensic analysis. Section 4 was devoted to the three most promising areas in which scientific community is working.

The new technological advances have yield an increase of data sources, each with their own technical specifications in terms of resolution, precision, quality, etc. At this point, data integration is a valuable tool in forensic engineering, since allows synergic combination of these diverse and heterogeneous sources into a reliable and accurate way, which contributes to a robust interpretation of the crime scene.

Moreover, there are new sensor advances which are still in a deployment phase. For this reason, their direct application in forensic science is not efficient. However, they have a great potential in forensic and only require a customization and algorithm adaptation in order to ease their use and maximize their performance. In a similar way, other sensors, that could fulfil these needs, have not yet been integrated in the common forensic workflows, due to their cost and/ or difficult to use (specialized training).

The wide variety of geomatic science solutions (hardware and software), their complexity and the difficulty of integration can divert the non‐expert user from the real aim: to assist forensic researchers. In order to prevent this, a high degree of automation is desirable for an effortless implementation in the forensic daily routine. The automation is a key issue for the non‐expert users of geomatic techniques, as well as, the provision of user interfaces focused on the forensic needs instead of the geomatic ones. In this regard, the developments of specifics tools for forensic tasks are aligned with this objective.
