Detection and Identification of Multiple Stationary Human Targets Via Bio-Radar Based on the Cross-Correlation Method

Abstract

Ultra-wideband (UWB) radar has been widely used for detecting human physiological signals (respiration, movement, etc.) in the fields of rescue, security, and medicine owing to its high penetrability and range resolution. In these applications, especially in rescue after disaster (earthquake, collapse, mine accident, etc.), the presence, number, and location of the trapped victims to be detected and rescued are the key issues of concern. Ample research has been done on the first issue, whereas the identification and localization of multi-targets remains a challenge. False positive and negative identification results are two common problems associated with the detection of multiple stationary human targets. This is mainly because the energy of the signal reflected from the target close to the receiving antenna is considerably stronger than those of the targets at further range, often leading to missing or false recognition if the identification method is based on the energy of the respiratory signal. Therefore, a novel method based on cross-correlation is proposed in this paper that is based on the relativity and periodicity of the signals, rather than on the energy. The validity of this method is confirmed through experiments using different scenarios; the results indicate a discernible improvement in the detection precision and identification of the multiple stationary targets.

Metrological Characterization for Vital Sign Detection by a Bioradar

“…The radar has been developed at IREA-CNR by using commercial off-the-shelf radio-frequency components. The system has an approximate size of 284 × 184 × 252 mm 3 and operates at discrete frequencies in the range between 1.8 and 3 GHz [13,14]. The radio signal emitted by the source is split into two equal parts: one part is radiated and the other part is used to generate two reference signals with 90 degrees phase offset, which are used to down convert the reflected signal at baseband.…”

“…The contactless measurement of vital signs with bioradar technique is valuable in several application fields such as security and surveillance, healthcare, and space medicine [1][2][3][4][5][6][7][8][9][10][11].…”

Detection and Localization for Multiple Stationary Human Targets Based on Cross-Correlation of Dual-Station SFCW Radars

“…To avoid the missed detection of weak targets, a single-radar correlation-based method is proposed in [22] to substitute the energy accumulation-based method. Based on a single-channel UWB pulse radar, the correlation coefficient of multiperiod echoes of each target is explored to identify the range information of all targets with different echo intensity.…”

“…2. Compared with existent energy-accumulation algorithms [19,20,23] and the single-radar correlation algorithm [22], the proposed cross-correlation algorithm of dual-station radars efficiently deals with the problem of the missed detection of weak targets even in the case of target occlusion for one of two radars.…”

“…3. In comparison to the two-channel processing algorithm [21] and single-radar correlation algorithm [22], the proposed cross-correlation algorithm dispenses with the additional-range pairing procedure, as two extracted ranges of each target for two radars are synchronously connected in the cross-correlation process.…”