title: Four-Element Receiver for Pulsed 10-mum Heterodyne Doppler Lidar.
abstract: A four-element photomixer receiver has been tested in a 10-mum heterodyne Doppler lidar. It addresses a reduction of the variance of the power scattered off distributed aerosols targets at ranges as long as 8 km. An improvement in performance is expected when the four independent signals recorded on every single shot are combined. Two summation techniques of the four signals have been implemented: a coherent summation of signal amplitude and an incoherent summation of intensities. A phasing technique for the four signals is proposed. It is based on a more suitable correlation time with discernible self-consistent packets (SCP's). The SCP technique has been successfully tested, and the results obtained with a coherent summation of the four signals, i.e., variance reduction, carrier-to-noise ratio improvement, and velocity accuracy improvement, are in agreement with theory.
authors.forename: X
authors.initials: X
authors.lastname: Favreau
authors.forename: A
authors.initials: A
authors.lastname: Delaval
authors.forename: P H
authors.initials: PH
authors.lastname: Flamant
authors.forename: A
authors.initials: A
authors.lastname: Dabas
authors.forename: P
authors.initials: P
authors.lastname: Delville