Reprints
http://hdl.handle.net/20.500.12489/738
2024-01-02T06:05:33ZConverted measurements random matrix approach to extended target tracking using X-band marine radar data
http://hdl.handle.net/20.500.12489/882
Converted measurements random matrix approach to extended target tracking using X-band marine radar data
Vivone, Gemine; Braca, Paolo; Granström, Karl; Natale, Antonio; Chanussot, Jocelyn
Conventional tracking algorithms rely upon the hypothesis of one detection per target for each frame. However, very fine spatial resolution radars represent widespread systems that provide data for which this hypothesis could be no longer valid. This problem is often called in the literature extended target tracking. In this paper we propose to use the well-established random matrix theory to deal with this issue. A suitable measurement model to address the radar's measurement noise and its conversion into Cartesian coordinates is proposed. The benefits of the proposed converted measurements - extended target tracking with regard to the problem of the targets' size estimation are demonstrated by using both simulated and real data acquired by an X-band marine radar. Average gains of 75% in the estimation of the targets' crossrange size and 31% for the along-range size are observed by comparing the proposed approach with the one that neglects the sensor's noises.
2019-01-01T00:00:00ZForward looking sonar mosaicing for mine countermeasures
http://hdl.handle.net/20.500.12489/881
Forward looking sonar mosaicing for mine countermeasures
Ferreira, Fausto; Djapic, Vladimir; Micheli, Michele; Caccia, Massimo
Forward looking sonars (FLS) are nowadays popular for many different applications. In particular, they can be used for Automatic Target Recognition (ATR) in the context of Mine Countermeasures. Currently, ATR techniques are applied to raw data which generates many false positives and the need for human supervision. Mosaicing FLS data increases target contrast and thus reduces false positive rate. Moreover, it implies a considerable data size reduction which is important if one thinks of exchange of data in real time through an acoustic channel with very limited bandwidth. Results of applying a real-time mosaicing algorithm to FLS data generated during Mine Countermeasures missions are shown and discussed thoroughly in this article.
2019-01-01T00:00:00ZDynamic underwater glider for environmental field estimation
http://hdl.handle.net/20.500.12489/880
Dynamic underwater glider for environmental field estimation
Grasso, Raffaele; Braca, Paolo; Fortunati, Stefano; Gini, Fulvio; Greco, Maria S.
A coordinated dynamic sensor network of autonomous underwater gliders to estimate three-dimensional time-varying environmental fields is proposed and tested. Integration with a network of surface relay nodes and asynchronous consensus are used to distribute local information and achieve the global field estimate. Field spatial sparsity is considered, and field samples are acquired by compressive sensing devices. Tests on simulated and real data demonstrate the feasibility of the approach with relative error performance within 10%.
2019-01-01T00:00:00ZReal-time mosaicing of large scale areas with forward looking sonar
http://hdl.handle.net/20.500.12489/879
Real-time mosaicing of large scale areas with forward looking sonar
Ferreira, Fausto; Djapic, Vladimir; Caccia, Massimo
Mosaicing of large scale areas is an important application in the field of underwater computer vision. Although most of the works use optical cameras for that purpose, Forward Looking Sonars, also called acoustic cameras, are becoming more popular due to recent advances with respect to resolution. Mapping a large area in real-time can be extremely important in certain applications such as search and rescue, postdisaster survey, surveillance or automatic target detection. In particular, the possibility of having a map created in real-time of the surveyed area can diminish the Post-Mission Analysis time and allow mission replanning. Results obtained for a marina dataset are hereby presented and the possible applications of this work are discussed.
2019-01-01T00:00:00Z