Joaquim Fortuny-Guasch

Ruinon landslide (Valfurva, Italy) activity in relation to rainfall by means of GBInSAR monitoring

The active Ruinon rockslide is located on the left bank of the Frodolfo River valley (Valfurva, Italian Alps) and is developed on the Confinale deep-seated gravitational slope deformation. Ruinon landslide is a major hazard for valley inhabitants in that rapid movement might dam the stream and create a debris flow. The landslide is strongly controlled by preexisting structural features and is believed to have been triggered by postglacial debuttressing. Ground-based radar interferometry has been used to map surface deformation over time of the entire unstable zone of Ruinon landslide with high spatial resolution and at a very high temporal acquisition rate (about five images per hour). The activity of the landslide shows strong periodicity, with summer and autumn accelerations and winter deceleration. From a correlation between the landslide acceleration and a class of rainfall event, we deduce the specific rainfall conditions that accelerate the instability of the landslide area. The study results suggest an improved tool for early warning of events of potentially catastrophic landslide instability.

Pulsed pseudolite signal effects on non-participating GNSS receivers

Pseudolites are a technology with the potential of bridging the gap between outdoor and indoor navigation. Despite their potential, pseudolites can cause severe interference problems with non-participating receivers, i.e., devices not designed to exploit this technology. In this paper, the loss caused by pulsed pseudolite signals is determined as a function of the pulse duty cycle and the number of bits employed for signal quantization. Quantization, blanking and noise increase are identified as the main sources of signal degradation. Theoretical results are validated by simulations and experiments performed using commercial GPS receivers. The good agreement between theoretical and experimental results supports the validity of the proposed approach.

Floor Detection with Indoor Vertical Positioning in LTE Femtocell Networks

Vertical positioning is nowadays a topic of high interest in indoor environments, due to the stringent requirements on indoor location accuracy for emergency calls, such as E911. Thus, indoor positioning techniques are investigated to achieve floor detection in order to fulfill these legal mandates. The use of Long Term Evolution (LTE) heterogeneous networks is an attractive solution due to the combination of communications and positioning capabilities. This paper provides an overview of the existing floor detection techniques. Practical results using Global Navigation Satellite Systems (GNSS), inertial sensors, barometer, and LTE signals are obtained in an experimental LTE femtocell network, within a deployment in a two-story building. Probabilities of floor detection above 67% of the cases are found for the positioning solutions assessed.

Ionospheric scintillation threats to GNSS in polar regions: The DemoGRAPE case study in Antarctica

This paper addresses the design and implementation of an Ionospheric Scintillation Monitoring Receiver based on the Software Defined Radio paradigm. The monitoring platform exploits a digital data grabber and a GNSS fully software receiver, which grants a high level of flexibility for the processing strategy and the storage of raw samples of the signals in case of meaningful scintillation events. Such an implementation approach yields valuable advantages in critical areas, such as polar regions, where resources are limited and installation or maintenance and replacement of GNSS receivers may be critical. The paper describes the successful installations of the platforms in two Antarctic stations, providing results at the same quality level of professional GNSS receivers used for ionospheric scintillation monitoring.