Showing papers by "Jirong Yu published in 2015"
TL;DR: The history of 2-μm laser development from early research to current state-of-the-art instrumentation and projected future space missions can be found in this paper, where a brief historical perspective of Tm:Ho work by early researchers is also given.
Abstract: NASA Langley Research Center (LaRC) has a long history of developing pulsed 2-μm lasers. From fundamental spectroscopy research, theoretical prediction of new materials, laser demonstration and engineering of lidar systems, it has been a very successful progress spanning around two decades. This article covers the 2-μm laser development from early research to current state-of-the-art instrumentation and projected future space missions. This applies to both global wind and carbon dioxide active remote sensing. A brief historical perspective of Tm:Ho work by early researchers is also given.
94 citations
TL;DR: Results indicate that the IPDA lidar system is capable of measuring water vapor and carbon dioxide differential optical depth with 0.5% and 0.2% accuracy from an altitude of 8 km to the surface and with 10 s averaging.
Abstract: Water vapor and carbon dioxide are the most dominant greenhouse gases directly contributing to the Earth's radiation budget and global warming. A performance evaluation of an airborne triple-pulsed integrated path differential absorption (IPDA) lidar system for simultaneous and independent monitoring of atmospheric water vapor and carbon dioxide column amounts is presented. This system leverages a state-of-the-art Ho:Tm:YLF triple-pulse laser transmitter operating at 2.05 μm wavelength. The transmitter provides wavelength tuning and locking capabilities for each pulse. The IPDA lidar system leverages a low risk and technologically mature receiver system based on InGaAs pin detectors. Measurement methodology and wavelength setting are discussed. The IPDA lidar return signals and error budget are analyzed for airborne operation on-board the NASA B-200. Results indicate that the IPDA lidar system is capable of measuring water vapor and carbon dioxide differential optical depth with 0.5% and 0.2% accuracy, respectively, from an altitude of 8 km to the surface and with 10 s averaging. Provided availability of meteorological data, in terms of temperature, pressure, and relative humidity vertical profiles, the differential optical depth conversion into weighted-average column dry-air volume-mixing ratio is also presented.
74 citations
TL;DR: Self-calibration feature of the 2-μm IPDA lidar allows one to monitor the transmitted laser energy, through residual scattering, with a single detection channel, which reduces the CO2 measurement uncertainty.
Abstract: Double-pulsed 2-μm 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-μm double-pulse laser energy monitor is presented. The design is based on an InGaAs pin quantum detector. A high-speed photoelectromagnetic 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-μm 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.
45 citations
Journal Article•
05 Jul 2015TL;DR: An airborne 2-micron double-pulsed Integrated Path Differential Absorption (IPDA) lidar has been developed for atmospheric CO2 measurements as discussed by the authors, which provides high precision measurement capability.
Abstract: An airborne 2-micron double-pulsed Integrated Path Differential Absorption (IPDA) lidar has been developed for atmospheric CO2 measurements. This new 2-miron pulsed IPDA lidar has been flown in spring of 2014 for total ten flights with 27 flight hours. It provides high precision measurement capability by unambiguously eliminating contamination from aerosols and clouds that can bias the IPDA measurement.
14 citations
TL;DR: In this article, the current development of the airborne double-pulsed and triple pulsed 2-μm CO 2 integrated path differential absorption (IPDA) lidar system at NASA LaRC is discussed.
Abstract: Carbon dioxide (CO 2 ) is an important greenhouse gas that significantly contributes to the carbon cycle and global radiation budget on Earth. CO 2 role on Earth’s climate is complicated due to different interactions with various climate components that include the atmosphere, the biosphere and the hydrosphere. Although extensive worldwide efforts for monitoring atmospheric CO 2 through various techniques, including in-situ and passive sensors, are taking place high uncertainties exist in quantifying CO 2 sources and sinks. These uncertainties are mainly due to insufficient spatial and temporal mapping of the gas. Therefore it is required to have more rapid and accurate CO 2 monitoring with higher uniform coverage and higher resolution. CO 2 DIAL operating in the 2-μm band offer better near-surface CO 2 measurement sensitivity due to the intrinsically stronger absorption lines. For more than 15 years, NASA Langley Research Center (LaRC) contributed in developing several 2-μm CO 2 DIAL systems and technologies. This paper focuses on the current development of the airborne double-pulsed and triple-pulsed 2-μm CO 2 integrated path differential absorption (IPDA) lidar system at NASA LaRC. This includes the IPDA system development and integration. Results from ground and airborne CO 2 IPDA testing will be presented. The potential of scaling such technology to a space mission will be addressed.
9 citations
20 Oct 2015
TL;DR: In this paper, a double-pulsed, 2-micron Integrated Path Differential Absorption (IPDA) lidar instrument for atmospheric carbon dioxide measurements is successfully developed at NASA Langley Research Center (LaRC).
Abstract: A double-pulsed, 2-micron Integrated Path Differential Absorption (IPDA) lidar instrument for atmospheric carbon dioxide (CO2) measurements is successfully developed at NASA Langley Research Center (LaRC). Based on direct detection technique, the instrument can be operated on ground or onboard a small aircraft. Key features of this compact, rugged and reliable IPDA lidar includes high transmitted laser energy, wavelength tuning, switching and locking, and sensitive detection. As a proof of concept, the IPDA ground and airborne CO2 measurement and validation will be presented. IPDA lidar CO2 measurements ground validation were conducted at NASA LaRC using hard targets and a calibrated in-situ sensor. Airborne validation, conducted onboard the NASA B-200 aircraft, included CO2 plum detection from power stations incinerators, comparison to in-flight CO2 in-situ sensor and comparison to air sampling at different altitude conducted by NOAA at the same site. Airborne measurements, spanning for 20 hours, were obtained from different target conditions. Ground targets included soil, vegetation, sand, snow and ocean. In addition, cloud slicing was examined over the ocean. These flight validations were conducted at different altitudes, up to 7 km, with different wavelength controlled weighing functions. CO2 measurement results agree with modeling conducted through the different sensors, as will be discussed.
3 citations
27 Sep 2015
TL;DR: In this article, a Mars orbiting 2-micron lidar system is presented, which is capable of measuring atmospheric pressure and temperature profiles using the most abundant atmospheric carbon dioxide (CO2) on Mars.
Abstract: Mars atmospheric characterization is critical for exploring the planet. Future Mars missions require landing massive payloads to the surface with high accuracy. The accuracy of entry, descent and landing (EDL) of a payload is a major technical challenge for future Mars missions. Mars EDL depends on atmospheric conditions such as density, wind and dust as well as surface topography. A Mars orbiting 2-micron lidar system is presented in this paper. This advanced lidar is capable of measuring atmospheric pressure and temperature profiles using the most abundant atmospheric carbon dioxide (CO2) on Mars. In addition Martian winds and surface altimetry can be mapped, independent of background radiation or geographical location. This orbiting lidar is a valuable tool for developing EDL models for future Mars missions.