Abstract: An improved method for determining whether a measurement point, measured using a differential absorption LIDAR (DIAL) system, represents a plume point or a non-plume point. Concentration path lengths (CPL's) for a plurality of measurement points are determined. An average non-plume CPL, CPL, is provided. For each measurement point, a standard deviation, CPLsd, is calculated based on first order error propagation and it is determined that the measurement point represents a non-plume point when the Hooshmand decision rule (HDR) is met. The HDR is given by, ( cpl - CPL _ CPL sd ) 2 > ( T ) 2 , where cpl is the corresponding CPL of the measurement point being tested and T is a threshold standard deviation level.

Abstract: A method of acquiring data uses multiple sensors in an aircraft. The method includes the steps of: (a) turning ON a DIAL sensor to detect a target of interest during a first flight pass over a region of interest (ROI), wherein the target of interest is a gas or oil pipeline leak; (b) detecting the target of interest using the DIAL sensor; and (c) storing location of the detected target in a look up table (LUT). The method also includes the steps of: (d) during a second flight pass over the ROI, triggering another sensor to turn ON at or about the location stored in the LUT; and (e) confirming presence of the target of interest using both ON-sensors. If necessary, a third flight pass over the ROI is conducted and yet another sensor is triggered to turn ON at or about the location stored in the LUT. Presence of the target of interest is confirmed using all three ON-sensors.

Abstract: A method for improving the accuracy of estimating concentration path length of a target molecule using a differential absorption LIDAR (DIAL) system. In particular, this method allows improved detection of plumes containing the target molecule against inhomogeneous background, such as uncovered ground or ground with various types of cover. In an embodiment of the present invention, spectral surface reflectivity variations are systematically corrected based on interpolation of surface reflectivity measurements of multiple offline beams of different wavelengths, which are relatively close to the online wavelength. In another embodiment, the signal to noise ratio of the received online pulse energy is improved by using multiple laser beams having the online wavelength and the signal to noise ratio of the received pulse energies at an offline wavelength is improved by using multiple laser beams having that offline wavelength.

Abstract: A multi-line tunable laser system, which uses lasers as light sources to illuminate, identify and or quantify one or more targets based on multi-dimensional spectral characteristics of each target. The system includes a plurality of laser sources, each tunable to emit an electromagnetic wave, and at least one tuning controller for tuning and locking each beam of light to a wavelength of required spectral line-width. The system also includes a transmitter for transmitting each beam of light to illuminate one or more targets, and a receiver for receiving light returning from the targets and converting the returned light to electrical signals for identifying and or quantifying the targets. The system further includes N tunable lasers where, M of the N lasers are each tuned to a wavelength that is partially absorbed by the targets, and L of the N (one or more) of the lasers are each tuned to a wavelength that is absorption-free of the targets.

Abstract: A system for remote quantitative detection of fluid leaks from a natural gas or oil pipeline by use of an airborne platform; including at least one laser light source for nearly simultaneous illuminating two or more target fluids and a background, wherein the two or more target fluids are characterized by two or more absorption wavelengths, and wherein the background has a different wavelength than either of the two or more target fluids. The illumination source is pointed based on a positioning system while in a geometric area along a path two or more target fluids are scanned for using the illumination sources. A signal detector detects the two or more target fluids using quantitative signal processing. Also included are a controller, a path planning and path finding tool for the positioning of the airborne platform, and a communicator for communicating the presence of the detected leak.