2018-11-15, Schwaninger, Adrian, Hättenschwiler, Nicole, Merks, Sarah

2018-10, Merks, Sarah, Hättenschwiler, Nicole, Zeballos, Melina, Schwaninger, Adrian, Pritchard, Daniel

2D multi-view X-ray imaging technology is widely used for security screening of hold baggage at airports. Newer technology is based on 3D CT imaging. Such systems offer the possibility to rotate a bag around 360 degrees. With the transition from 2D multi-view to advanced CT imaging, the question arises whether airport security officers (screeners) need the same visualcognitive abilities when visually inspecting X-ray images of hold baggage. This study investigated the relationship between visualcognitive abilities and visual inspection performance of screeners. Screeners conducted a computer-based visual cognitive test battery (VCTB) and a simulated hold baggage screening task with 2D and 3D imaging. We found that aspects of processing speed and visual processing correlated significantly with visual inspection performance of screeners using 2D imaging technology. In comparison, performance of screeners that visually inspected 3D images showed less correlations with the VCTB. These results indicate that with the expected change from 2D to 3D imaging technology in airport security, visual-cognitive requirements of the screeners might change. Therefore, further studies need to elucidate in more detail what visual-cognitive skills future 3D screeners need as it could affect personnel selection and development.

2018-06, Merks, Sarah, Schwaninger, Adrian, Hättenschwiler, Nicole, Sterchi, Yanik, Mendes, Marcia, Hügli, David

2017-09-25, Sterchi, Yanik, Hättenschwiler, Nicole, Michel, Stefan, Schwaninger, Adrian

2018-10-15, Schwaninger, Adrian, Hättenschwiler, Nicole, Sterchi, Yanik, Mendes, Marcia, Hügli, David, Merks, Sarah

2018-10, Hättenschwiler, Nicole, Merks, Sarah, Schwaninger, Adrian, Pritchard, Daniel

In airport security screening, passenger baggage that is transported in the hold of an aircraft (hold baggage) is screened using X-ray machines with explosive detection technology. Older systems are based on 2D multi-view imaging whereas newer systems are based on computer tomography (CT) that features 3D rotatable images (3D imaging). Regulators, airport operators and security providers currently discuss whether extensive and specific training is necessary for screeners who are used to 2D multi-view imaging before they start working with 3D imaging. Moreover, to facilitate the decision making of screeners, so called on-screen alarm resolution protocols (OSARP) are available for 3D imaging. However, their effectiveness has not been investigated yet. To address these issues, we compared the visual inspection performance of screeners using state-of-the-art 2D multi-view imaging versus 3D imaging versus 3D imaging following a specific on-screen alarm resolution protocol (OSARP). In a simulated hold baggage screening task, screeners had to decide whether X-ray images contained an improvised explosive device (IED) or not. Results showed that there was no difference in detection performance (d') between 2D and 3D imaging. Visual inspection with 3D imaging following an OSARP resulted in higher detection performance (d') compared to 2D and 3D imaging. In conclusion, screeners currently working with 2D multi-view technology do not need extensive and specific training to achieve comparable detection performance with 3D imaging. The application of an OSARP has the potential to further increase screeners’ detection performance (d') with 3D imaging.

2018-05, Hättenschwiler, Nicole, Sterchi, Yanik, Mendes, Marcia, Schwaninger, Adrian

Bomb attacks on civil aviation make detecting improvised explosive devices and explosive material in passenger baggage a major concern. In the last few years, explosive detection systems for cabin baggage screening (EDSCB) have become available. Although used by a number of airports, most countries have not yet implemented these systems on a wide scale. We investigated the benefits of EDSCB with two different levels of automation currently being discussed by regulators and airport operators: automation as a diagnostic aid with an on-screen alarm resolution by the airport security officer (screener) or EDSCB with an automated decision by the machine. The two experiments reported here tested and compared both scenarios and a condition without automation as baseline. Participants were screeners at two international airports who differed in both years of work experience and familiarity with automation aids. Results showed that experienced screeners were good at detecting improvised explosive devices even without EDSCB. EDSCB increased only their detection of bare explosives. In contrast, screeners with less experience (tenure < 1 year) benefitted substantially from EDSCB in detecting both improvised explosive devices and bare explosives. A comparison of all three conditions showed that automated decision provided better human–machine detection performance than on-screen alarm resolution and no automation. This came at the cost of slightly higher false alarm rates on the human–machine system level, which would still be acceptable from an operational point of view. Results indicate that a wide-scale implementation of EDSCB would increase the detection of explosives in passenger bags and automated decision instead of automation as diagnostic aid with on screen alarm resolution should be considered.

2018-10-04, Sterchi, Yanik, Hättenschwiler, Nicole, Mendes, Marcia, Hügli, David, Merks, Sarah, Schwaninger, Adrian

2018-07, Schwaninger, Adrian, Merks, Sarah, Hättenschwiler, Nicole, Sterchi, Yanik, Mendes, Marcia, Hügli, David

2017-12-07, Sterchi, Yanik, Hättenschwiler, Nicole, Michel, Stefan, Schwaninger, Adrian