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Self-Calibration and Laser Energy Monitor Validations for a Double-Pulsed 2-Micron CO2 Integrated Path Differential Absorption Lidar ApplicationDouble-pulsed 2-micron integrated path differential absorption (IPDA) lidar is well suited for atmospheric CO2 remote sensing. The IPDA lidar technique relies on wavelength differentiation between strong and weak absorbing features of the gas normalized to the transmitted energy. In the double-pulse case, each shot of the transmitter produces two successive laser pulses separated by a short interval. Calibration of the transmitted pulse energies is required for accurate CO2 measurement. Design and calibration of a 2-micron double-pulse laser energy monitor is presented. The design is based on an InGaAs pin quantum detector. A high-speed photo-electromagnetic quantum detector was used for laser-pulse profile verification. Both quantum detectors were calibrated using a reference pyroelectric thermal detector. Calibration included comparing the three detection technologies in the single-pulsed mode, then comparing the quantum detectors in the double-pulsed mode. In addition, a self-calibration feature of the 2-micron IPDA lidar is presented. This feature allows one to monitor the transmitted laser energy, through residual scattering, with a single detection channel. This reduces the CO2 measurement uncertainty. IPDA lidar ground validation for CO2 measurement is presented for both calibrated energy monitor and self-calibration options. The calibrated energy monitor resulted in a lower CO2 measurement bias, while self-calibration resulted in a better CO2 temporal profiling when compared to the in situ sensor.
Document ID
20160010657
Acquisition Source
Langley Research Center
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Refaat, Tamer F.
(NASA Langley Research Center Hampton, VA, United States)
Singh, Upendra N.
(NASA Langley Research Center Hampton, VA, United States)
Petros, Mulugeta
(NASA Langley Research Center Hampton, VA, United States)
Remus, Ruben
(NASA Langley Research Center Hampton, VA, United States)
Yu, Jirong
(NASA Langley Research Center Hampton, VA, United States)
Date Acquired
August 30, 2016
Publication Date
August 20, 2015
Publication Information
Publication: Applied Optics
Volume: 54
Issue: 24
ISSN: 1559-128X
Subject Category
Earth Resources And Remote Sensing
Report/Patent Number
NF1676L-20889
Funding Number(s)
WBS: WBS 478643.02.09.02.02
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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