Leanne L. West

Hazard Detection Analysis for a Forward-Looking Interferometer

The Forward-Looking Interferometer (FLI) is a new instrument concept for obtaining the measurements required to alert flight crews to potential weather hazards to safe flight. To meet the needs of the commercial fleet, such a sensor should address multiple hazards to warrant the costs of development, certification, installation, training, and maintenance. The FLI concept is based on high-resolution Infrared Fourier Transform Spectrometry (FTS) technologies that have been developed for satellite remote sensing. These technologies have also been applied to the detection of aerosols and gases for other purposes. The FLI concept is being evaluated for its potential to address multiple hazards including clear air turbulence (CAT), volcanic ash, wake vortices, low slant range visibility, dry wind shear, and icing during all phases of flight (takeoff, cruise, and landing). The research accomplished in this second phase of the FLI project was in three major areas: further sensitivity studies to better understand the potential capabilities and requirements for an airborne FLI instrument, field measurements that were conducted in an effort to provide empirical demonstrations of radiometric hazard detection, and theoretical work to support the development of algorithms to determine the severity of detected hazards

Improved night vision demonstrator program status

Although existing night vision equipment provides a significant improvement in target detection in low light conditions, there are several limitations that limit their effectiveness. Focus is a significant problem for night vision equipment due to the low f-number optics required to obtain sufficient sensitivity as well as the dynamic nature of night vision applications, which requires frequent focus adjustments. The Georgia Tech Research Institute has developed a prototype next-generation night vision device called the Improved Night Vision Demonstrator (INVD) in order to address these shortfalls. This paper will describe the design of the INVD system as well as an analysis of its performance.

Hyperspectral image turbulence measurements of the atmosphere

A Forward Looking Interferometer (FLI) sensor has the potential to be used as a means of detecting aviation hazards in flight. One of these hazards is mountain wave turbulence. The results from a data acquisition activity at the University of Colorados Mountain Research Station will be presented here. Hyperspectral datacubes from a Telops Hyper-Cam are being studied to determine if evidence of a turbulent event can be identified in the data. These data are then being compared with D&P TurboFT data, which are collected at a much higher time resolution and broader spectrum.

Detection of aircraft exhaust in hyperspectral image data

The use of a hyperspectral imaging system for the detection of gases has been investigated, and algorithms have been developed for various applications. Of particular interest here is the ability to use these algorithms in the detection of the wake disturbances trailing an aircraft. A dataset of long wave infrared (LWIR) hyperspectral datacubes taken with a Telops Hyper-Cam at Hartsfield-Jackson International Airport in Atlanta, Georgia is investigated. The methodology presented here assumes that the aircraft engine exhaust gases will become entrained in wake vortices that develop; therefore, if the exhaust can be detected upon exiting the engines, it can be followed through subsequent datacubes until the vortex disturbance is detected. Gases known to exist in aircraft exhaust are modeled, and the Adaptive Coherence/Cosine Estimator (ACE) is used to search for these gases. Although wake vortices have not been found in the data, an unknown disturbance following the passage of the aircraft has been discovered.

A next-generation ground-based sensor for tropospheric ozone

Excessive concentrations of ground-level ozone present a public health hazard in polluted environments. The Environmental Protection Agency currently rates air quality problems in several metropolitan areas in the United States as either serious or severe. These cities are required to have plans in place for improving air quality. In general, they also attempt to forecast peak ground-level ozone concentrations at the start of each day during the summer months. Air quality improvement strategies and daily forecasts are based on models in which both the science and the input data are very limited. The models are three-dimensional, but conventional ground-based ozone monitoring networks are only two-dimensional. For this reason, we are developing an unattended ozone lidar to be manufactured in multiple units and deployed at several locations throughout a metropolitan region. The lidars will add the third dimension to the data and enable researchers to fully understand ground level ozone concentrations. In this paper we describe the design considerations for the lidars.

Non-invasive, multi-modal sensing of skin stretch and bioimpedance for detecting infiltration during intravenous therapy

Intravenous infiltration is a condition wherein an infused solution leaks inadvertently into soft tissue surrounding a hypodermic needle site. This occurrence affects approximately 6.5% of patients in hospitals worldwide, and can lead to severe tissue damage if not treated immediately. The methods currently used by medical staff to detect an infiltration are subjective and can potentially be prone to error. Infiltration is an even larger concern in pediatric patients, who have smaller veins than adults and have more difficulty in communicating pain or other discomfort associated with the infiltration with medical staff. For these reasons, automatic IV infiltration detection could potentially reduce the risk associated with this damaging condition. This paper proposes a novel proof-of-concept system that uses non-invasive sensing in conjunction with a low-power embedded computing platform to deliver continuous infiltration monitoring around the IV catheter site. This kind of system could be able to detect an infiltration by non-invasively monitoring for known symptoms: swelling of soft tissue and increased skin firmness; these symptoms can be sensed by measuring skin stretch and local bioimpedance. Moreover, the low-power design and wireless capabilities can potentially enable continuous wear. The proposed automatic IV infiltration detection system could significantly improve the number of infiltrations identified and treated on time.

Interferometric radiometer for in-flight detection of aviation hazards

The Forward-Looking Interferometer (FLI) is a new instrument concept for obtaining the measurements required to alert flight crews to potential weather hazards to safe flight. To meet the needs of the commercial fleet, such a sensor should address multiple hazards to warrant the costs of development, certification, installation, training, and maintenance. The FLI concept is based on high-resolution Infrared Fourier Transform Spectrometry (FTS) technologies that have been developed for ground based, airborne, and satellite remote sensing. The FLI concept is being evaluated for its potential to address multiple hazards including clear air turbulence (CAT), volcanic ash, wake vortices, low slant range visibility, dry wind shear, and icing, during all phases of flight. This project has three major elements: further sensitivity studies and applications of EOF (Empirical Orthogonal Function) Regression; development of algorithms to estimate the hazard severity; and field measurements to provide an empirical demonstration of the FLI aviation hazard detection and display capability. These theoretical and experimental studies will lead to a specification for a prototype airborne FLI instrument for use in future in-flight validation. The research team includes the Georgia Tech Research Institute, Hampton University, the University Corporation for Atmospheric Research, the Air Force Institute of Technology, and the University of Wisconsin.

Lidar education at Georgia Tech

The Georgia Tech Research Institutes atmospheric laser radar (lidar) team became involved in education projects starting in 2001, when we developed an eye safe lidar with undergraduate women at Agnes Scott College in Decatur, Georgia. We have initiated several other projects since that time, including short courses, an academic course at Georgia Tech, a lidar textbook, and a lidar system designed specifically for education. The lidar education program at GTRI is reviewed here with comments about future plans and prospects.

Hands-Free Focus Night Vision Technology Demonstration

The Georgia Tech Research Institute is currently developing a device to demonstrate a hands-free focus technology for head-mounted night vision sensors. The demonstrator device will integrate a computational imaging technique that increases depth of field with a digital night vision sensor. The goal of the demonstrator is to serve as a test bed for evaluating the critical performance/operational parameters necessary for the hands-free focus technology to support future tactical night vision concepts of operation. This paper will provide an overview of the technology studies and design analyses that have been performed to date as well as the current state of the demonstrator design.

NEXLASER - an unattended tropospheric aerosol and ozone lidar - first results

This paper describes the current status of a project to develop an unattended lidar system known as NEXLASER that will provide real-time tropospheric aerosol and ozone profiles. An unattended system requires a robust, eye-safe optical design that can provide the necessary signal levels and dynamic range to produce profiles at the required height, resolution and accuracy. An equally important consideration for automated data reduction is a set of algorithms to compute aerosol and ozone profiles under a wide range of atmospheric conditions. A laboratory prototype of the NEXLASER lidar has been developed and operated. Examples of continuously monitored aerosol extinction coefficients and ozone concentrations are presented.