Caroline S. Turcotte

Airborne infrared hyperspectral imager for intelligence, surveillance and reconnaissance applications

Persistent surveillance and collection of airborne intelligence, surveillance and reconnaissance information is critical in today’s warfare against terrorism. High resolution imagery in visible and infrared bands provides valuable detection capabilities based on target shapes and temperatures. However, the spectral resolution provided by a hyperspectral imager adds a spectral dimension to the measurements, leading to additional tools for detection and identification of targets, based on their spectral signature. The Telops Hyper-Cam sensor is an interferometer-based imaging system that enables the spatial and spectral analysis of targets using a single sensor. It is based on the Fourier-transform technology yielding high spectral resolution and enabling high accuracy radiometric calibration. It provides datacubes of up to 320×256 pixels at spectral resolutions as fine as 0.25 cm-1. The LWIR version covers the 8.0 to 11.8 μm spectral range. The Hyper-Cam has been recently used for the first time in two compact airborne platforms: a bellymounted gyro-stabilized platform and a gyro-stabilized gimbal ball. Both platforms are described in this paper, and successful results of high-altitude detection and identification of targets, including industrial plumes, and chemical spills are presented.

Airborne infrared hyperspectral imager for intelligence, surveillance, and reconnaissance applications

Persistent surveillance and collection of airborne intelligence, surveillance and reconnaissance information is critical in todays warfare against terrorism. High resolution imagery in visible and infrared bands provides valuable detection capabilities based on target shapes and temperatures. However, the spectral resolution provided by a hyperspectral imager adds a spectral dimension to the measurements, leading to additional tools for detection and identification of targets, based on their spectral signature. The Telops Hyper-Cam sensor is an interferometer-based imaging system that enables the spatial and spectral analysis of targets using a single sensor. It is based on the Fourier-transform technology yielding high spectral resolution and enabling high accuracy radiometric calibration. It provides datacubes of up to 320×256 pixels at spectral resolutions as fine as 0.25 cm-1. The LWIR version covers the 8.0 to 11.8 μm spectral range. The Hyper-Cam has been recently used for the first time in two compact airborne platforms: a belly-mounted gyro-stabilized platform and a gyro-stabilized gimbal ball. Both platforms are described in this paper, and successful results of high-altitude detection and identification of targets, including industrial plumes, and chemical spills are presented.

Airborne measurements in the infrared using FTIR-based imaging hyperspectral sensors

Hyperspectral ground mapping is being used in an ever-increasing extent for numerous applications in the military, geology and environmental fields. The different regions of the electromagnetic spectrum help produce information of differing nature. The visible, near-infrared and short-wave infrared radiation (400 nm to 2.5 μm) has been mostly used to analyze reflected solar light, while the mid-wave (3 to 5 μm) and long-wave (8 to 12 μm or thermal) infrared senses the self-emission of molecules directly, enabling the acquisition of data during night time. Push-broom dispersive sensors have been typically used for airborne hyperspectral mapping. However, extending the spectral range towards the mid-wave and long-wave infrared brings performance limitations due to the self emission of the sensor itself. The Fourier-transform spectrometer technology has been extensively used in the infrared spectral range due to its high transmittance as well as throughput and multiplex advantages, thereby reducing the sensor self-emission problem. Telops has developed the Hyper-Cam, a rugged and compact infrared hyperspectral imager. The Hyper-Cam is based on the Fourier-transform technology yielding high spectral resolution and enabling high accuracy radiometric calibration. It provides passive signature measurement capability, with up to 320x256 pixels at spectral resolutions of up to 0.25 cm-1. The Hyper-Cam has been used on the ground in several field campaigns, including the demonstration of standoff chemical agent detection. More recently, the Hyper-Cam has been integrated into an airplane to provide airborne measurement capabilities. A special pointing module was designed to compensate for airplane attitude and forward motion. To our knowledge, the Hyper-Cam is the first commercial airborne hyperspectral imaging sensor based on Fourier-transform infrared technology. The first airborne measurements and some preliminary performance criteria for the Hyper-Cam are presented in this paper.

Developments in Thermal HSI Sensing at Defence R&D Canada - Valcartier Research Centre

Defence Research and Development Canada (DRDC) - Valcartier Research Centre has been developing a ground-based and airborne thermal hyperspectral imaging capability for several years. A summary of recent initiatives focusing on the detection of chemical vapours and powders will be presented in this talk. Article not available.

Detection of unexploded ordnance using airborne LWIR emissivity signatures

This paper investigated the potential of using LWIR spectral emissivity signatures to detect unexploded ordnance in the impact ranges of the Canadian Forces Bases. The experimental setup was composed of inert projectiles of various sizes and coating, and various potential false alarm objects. LWIR Hypercam images were acquired at 30 minutes intervals between 9:30 on Aug 23 and 21h00 on Aug 24 2013 from a height of 20m at nadir. Images were processed to emissivity and the Generalized Likelihood Ratio Test (GLRT) was used to perform the detection. Results show that the GLRT is suitable for detecting the paint used to cover the projectiles if they are not covered by vegetation. Other detected targets, such as glass and wood, are spectrally distinct and would not appear as false alarms.

Novel compact airborne platform for remote sensing applications using the Hyper-Cam infrared hyperspectral imager

High resolution broad-band imagery in the visible and infrared bands provides valuable detection capabilities based on target shapes and temperatures. However, the spectral resolution provided by a hyperspectral imager adds a spectral dimension to the measurements, which leads to an additional means of detecting and identifying targets based on their spectral signature. The Telops Hyper-Cam sensor is an interferometer-based imaging system that enables the spatial and spectral analysis of targets using a single sensor. It is based on the Fourier-transform technology, which yields high spectral resolution and enables a high accuracy radiometric calibration. It provides datacubes of up to 320×256 pixels at spectral resolutions as fine as 0.25 cm-1. The LWIR version covers the 8.0 to 11.8 μm spectral range. The Hyper-Cam has been recently integrated and flown on a novel airborne gyro-stabilized platform inside a fixed-wing aircraft. The new platform, more compact and more advanced than its predecessor, is described in this paper. The first results of target detection and identification are also presented.

Iterative Signature Suppression for detection and identification of gas plume constituents

In the case of long-wave infrared (LWIR) hyperspectral images, the detection and identification of all gas constituents in a plume is not well achieved by common detectors such as the Adaptive Cosine Estimator (ACE) and the structural background Generalized Likelihood Ratio Test (GLRT). This paper proposes a new approach for hyperspectral imaging called “Iterative Signature Suppression (ISS)” based on the iterative use of the structural background GLRT to detect all gaseous mixture components. The idea behind this method, is to add a previously identified gas signature to the background sub-space in order to“subtract” this signal by applying the GLRT again. The results have shown that the ISS method can improve the detection of gas plume constituents hidden under the strongest gas in the plume.

Current ground-based LWIR his remote sensing activities at Defense R&D Canada — Valcartier

Recently, DRDC Valcartier has been investigating novel ground-based longwave hyperspectral imaging (HSI) remote sensing techniques. Specific projects include the development of a new ground-based sensor called MoDDIFS (Multi-Option Differential Detection and Imaging Fourier Spectrometer), which is a leading edge infrared (IR) hyperspectral imaging (HSI) sensor optimized for the standoff detection of explosive vapours and precursors. The development of the MoDDIFS sensor is based on the integration of two innovative technologies: (1) the differential Fourier-transform infrared (FTIR) radiometry technology found in the Compact Atmospheric Sounding Interferometer (CATSI) previously developed by DRDC Valcartier, and (2) the HSI technology developed by Telops. The MoDDIFS sensor will offer the optical subtraction capability of the CATSI system but at high-spatial resolution using an MCT focal plane array of 84×84 pixels. The MoDDIFS sensor offers the potential of simultaneously measuring differential linear polarizations to further reduce the clutter in the measured radiance.

Current airborne LWIR HSI remote sensing activities at Defence R&D Canada — Valcartier

Recently, DRDC Valcartier has been investigating longwave hyperspectral imaging (HSI) remote sensing techniques using airborne sensors. There is currently an initiative to test the commercially available ground-based Hyper-Cam HSI system, developed by Telops, on a stabilized airborne platform with an integrated image motion compensation capability. The Hyper-Cam is also based on the Fourier-transform technology yielding high spectral resolution and enabling high accuracy radiometric calibration. It provides passive signature measurement capability, with up to 320×256 pixels at spectral resolutions of up to 0.25 cm−1. To our knowledge, the Hyper-Cam is the first commercial airborne hyperspectral imaging sensor based on Fourier-transform infrared technology. Airborne measurements and some preliminary performance criteria for the Hyper-Cam are presented in this paper.

First field trial results of the MR-CATSI dual input beam spectroradiometer for the standoff detection of chemicals

The MR-CATSI combines the latest ABB Bomem MR spectro-radiometer technology and software with the concepts used in the design of the ABB and DRDC CATSI instrument twelve years ago. This instrument is a Fourier transform spectro-radiometer with dual input beams. It is a passive, stand-off sensor. One input port can be directed to the area to be interrogated while the other input beam can be pointed at the background. The instrument automatically measures the difference of spectral radiance between the target and the background, hence achieving a suppression of the background signal. The resulting measurement is the unique spectral signature of the target. The system includes a software module to control the instrument and the acquisition parameters, a module for the radiometric calibration and a module to perform the identification and quantification, in real time, of various gases. Overview of the design and results from field trials will be presented. This includes recent measurements of a number of gas plumes.