Search NASA⌕ Search

Engineering topics

Bambha, Ray

Publications and source records attributed to Bambha, Ray.

At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Method and system for multi-pass laser-induced incandescence

Various technologies for measurement of properties of a particulate suspended in a gas phase via laser-induced incandescence (LII) are described herein. A beam of light can be emitted into a multi-pass optical cell using a laser. The multi-pass optical cell comprises a system of one or more mirrors that repeatedly reflects the beam through a measurement region, stimulating incandescence of particulates present in the measurement region. An LII detection system having a field of view that encompasses the measurement region then receives blackbody or quasi-blackbody radiation emitted by the incandescing particles and outputs data indicative of one or more properties of the particulates in the measurement region.

Bambha, Ray↗
DOE OSTI2015

hsrl (01)

High-spectral-resolution lidar (HSRL) systems collect data about clouds and aerosols. These systems provide vertical profiles of optical depth, backscatter cross-section, depolarization, and backscatter phase function. All HSRL measurements are absolutely calibrated by reference to molecular scattering, which is measured at each point in the lidar profile. Like the Raman lidar, but unlike simple backscatter lidars such as the micropulse lidar, the HSRL can measure backscatter cross-sections and optical depths without prior assumptions about the scattering properties of the atmosphere. The depolarization observations also allow robust discrimination between ice and water clouds. In addition, rigorous error estimates can be computed for all measurements. A very narrow, angular field of view reduces multiple scattering contributions. The small field of view, coupled with a narrow optical bandwidth, nearly eliminates noise due to scattered sunlight. ARM operates two HSRL systems, one at the Barrow, North Slope of Alaska (NSA) site and the other in the second ARM Mobile Facility (AMF2), which is deployed at various locations on field campaigns.

54 ENVIRONMENTAL SCIENCES↗