TEAM PEREGRINE

Chemical Agent Detection from Small Unmanned Aerial System Using

Hyperspectral Sensorat the

Office of the Secretary of DefenseRapid Reaction Technology Office (RRTO)

THUNDERSTORM 15-323-25 February 2015

Camp Shelby, MS

Objectives

THUNDERSTORM 15-3 Focus Area: Explore emerging technologies for their technical applications and their potential to use a battery-powered Vertical Take-Off and Land (VTOL) Unmanned Aerial System (UAS) to support the detection and identification of chemical and/or biological Weapons of Mass Destruction (WMD).

TEAM PEREGRINE: •Integrate sUAS and Nano-Hyperspec® Hyperspectral (HSI) Sensor•Adapt sUAS Flight Characteristics to Accommodate HSI Data

Collection•Demonstrate Chemical Agents Detection Through Hyperspectral Data

Analysis

• Camp Shelby, Hattiesburg Mississippi • Combined Arms Collective Training Facility (CACTF)• Data was collected on 24 February 2015 at approximately 1030hrs

Location/Environment

23 FEB50%

46/34

24 FEB 25FEB40% 100%

38/3242/35

Weather

CACTF

Simulant Chemical Target Material Methyl Salicylate (MES)

Target Environment

• Urban environment of various building materials, structures and sizes.

• Dispersal Method: Placed on black plastic, clear plastic, soil and concrete

Target Characteristics

• Standard US Army Chemical Simulant• Complex organic ester naturally produced by

many species of plants, particularly wintergreens

sUAS System Overview

Hyperspectral SensorKey Specifications:• 640 spatial bands• 270 spectral bands• ~2.2nm spectral sampling interval• 5nm spectral resolution (FWHM with 20-micron slit)• 17mm lens (others available and switchable)• 480GB storage capacity (~ 130 minutes at 100 fps)• Connectivity: Gigabit Ethernet• Size 3" x 3" x 4.72" (76.2mm x 76.2mm x 119.92mm)• Weight: less than 1.6 lb. (0.72kg)

Small Unmanned Aerial SystemKey Specifications:• Hex Multicopter Frame• 3DR Pixhawk Open-Source Flight Controller• Fully Autonomous Flight Control and Mission Planning• Endurance 13-17 min with options for longer flights• Data processed post-flight• Weight: less than 8 lbs

640px

270“Layers”

Planned Mission

Flown Mission

Mission Planning

Autonomous Route• 5-meter/second Speed• 300 Feet Altitude• Flight Duration 7 Minutes

MES Target Information

Provided• Located within Polygon• Dispersed on and near structures

Flight PatternTarget Boundary

Mission As Flown• Nadir coverage from sensor• Computer controlled

(Autonomous) flight

Target Detection / Identification

Detection 2Detection 1

Detection 3

Data Processing Parameters • Visible-Near Infrared (VNIR) (400-1000nm) Hyperspectral (HSI) data was

calibrated to spectral radiance and ortho-rectified• Calibrated images were atmospherically corrected using a modified flat field

technique• Bad bands were removed from each image• Target detection for the MES lab signature was performed using

• Matched Filter• Spectral Angle Mapper• Constrained Energy Minimization• Adaptive Coherence Estimator

• Positive detections and false positives suppression used thresholds employing a weights of evidence model for the performance of all four algorithms

Calibration factors for modified flat field correction

• Lab spectrum for MES plotted in RED vs detected spectral signatures for MES in-scene

• Detection 1 depicts a much higher concentration of the MES chemical than Detection 2

• Detection 3 depicts a higher concentration than Detection 2 but lower than Detection 1

Detection 2Detection 1

Detection 3

Spectral Identification

Accomplishments

• sUAS Frame-Mounted Hyperspectral Sensor Collects Push Broom Imagery that enables Detailed Analytics of the Data Cube, such as target detection and identification

• Data Cube Analytics Enable Positive Identification of Target Simulant Material (Methyl salicylate)

• No “False Positive” Detections Within the Data Cube

• Identify Areas for Improvements in Optimal System sUAS, Sensor, Data Analytic Software Integration Real-Time Analysis and Reporting for Collected Data Autonomous Flight Control

• Able to Collect Actionable Data Despite Overcast Skies