Measurements and Analysis of the Doppler Signature of a Human Moving within the Forest in UHF-Band

Abstract

Measurements of the Doppler signature in UHF-band of a human moving in outdoor sites are presented in this paper. A radar campaign has been carried out, observing a subject walking and running outside, near and within a forest. A bistatic radar has been employed working in continuous wave (CW) at 1 GHz and 435 MHz. The spectrograms acquired in VV polarization are shown and discussed. This study aims to prove the feasibility of detecting people moving in forested areas at low frequencies. Besides, we highlight the impact of the frequencies and the different sites on the Doppler spectrum of the human motions. The Doppler frequency signature of the moving man has been well detected at 1 GHz and 435 MHz for each motor activity and scene. The working frequency 435 MHz has proved to be more efficient for the detection and classification of the physical activities.

Time‐frequency characterisation of bistatic Doppler signature of a wooded area walk at L‐band

“…However, these features are not sufficient to characterise physical activity. The Doppler bandwidth and the offset allow distinguishing walks performed at different speeds or other activities such as running, boxing, and crawling [17, 34]. In this respect, PWVD provides unreasonable values that do not allow the observed physical activity’s correct characterisation.…”

“…The description of the bistatic radar and of the setup chosen for both the numerical tests and the measurements has been presented in the previous work [17]. We summarise the basic parameters as follows.…”

“…In a previous work [17], we have analysed at L‐ and UHF‐band, the time variation of the frequency signature of a subject walking and running in a wooded area. We have presented the walk and run’s measured spectrograms whose backscattering signals have been collected employing a bistatic radar operating at 1 GHz (L‐band) and 435 MHz (UHF‐band).…”

A Numerically Efficient Method for Predicting the Scattering Characteristics of Complex Moving Targets

“…In [23], the authors simulate the Doppler response of a target with rotating parts, using a ray technique. In [24] and [25], modeling of the scattered response of human bodies was carried out. However, no electromagnetic calculation was performed so that the physical complexity was avoided.…”

Dual-Conversion Microwave Down Converter for Nanosatellite Electronic Warfare Systems

“…Another interesting feature of the proposed down converter concerns the possibility to be exploited for different applications. Indeed, its wide operating bandwidth includes the operating frequencies of a great number of applications, e.g., satellite communication, radars, etc., where it can used as receiving stage [18][19][20][21][22][23].…”