3/9/2007

1. ECE5320 MechatronicsAssignment#01: Literature Survey on Sensors and Actuators Topic: Hyperspectral Imaging Sensors Prepared by: Shelley Rounds Dept. of Electrical and Computer Engineering Utah State University E: shelleyr@cc.usu.edu T: (801)884-9235 3/9/2007

2. Outline • Reference list • To probe further • Applications • Basic working principle • Identification • Material Spectra Examples • Sample Configuration • Specifications • Limitations • Alternatives • Cost ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

3. Reference List • http://www.asprs.org/publications/pers/2004journal/april/highlight.pdf • http://www.globalsecurity.org/intell/library/imint/hyper.htm • http://en.wikipedia.org/wiki/Hyperspectral_imaging • www.microimages.com/getstart/pdf_new/hyprspec.pdf • K. Fife, “Hyperspectral Imaging for UAVs” • C. Mao, J. Heitschmidt, “Hyperspectral imaging with liquid crystal tunable filter for biological and agricultural assessment,” SPIE, Conference on Precision Agriculture and Biological Quality, Boston Mass., Nov. 1998. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

4. To explore further (survival pointers of web references etc) • http://www.techexpo.com/WWW/opto-knowledge/IS_resources.html • http://en.wikipedia.org/wiki/Panchromatic • http://en.wikipedia.org/wiki/Multi-spectral_image • http://en.wikipedia.org/wiki/Spectrometer ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

5. Applications • New Technology • Hyperspectral imaging is still in its infancy • Its application potential is not yet fully realized • Current Fields of Use • Military • Agriculture • Biology • Structural Engineering ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

6. Current Applications • Target Detection • Thermal Emissions • Hazardous Waist • Biological and Chemical Weapons • Plant Disease • Oil Seeps • Material Mapping/Material Identification • Mineral Mapping • Toxic Waist Mapping in Mines • Mapping Detailed Surfaces • Soil Moisture • Plant Canopy Chemistry ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

7. Current Applications Major Advantage Objects and materials smaller than the pixel size can be identified www.globalsecurity.org ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

8. Basic Working Principle • What is hyperspectral imaging? • How does it work? www.microimages.com ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

9. Basic Working Principle • Hyerspactral Image • A 3D cubic data set with one spectral dimension and two spatial dimensions. • Constructing 3D Cubic Set • Hundreds of images are taken of the same area (two spatial dimensions) • Each image captures the reflectance of the area at a different wavelength (one spectral dimension) • The images are stacked together to create a cube www.globalsecurity.org ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

10. Basic Working Principle www.microimages.com ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

11. Basic Working Principle • Image Process • An optical dispersing element such as a grating or prism splits light into many narrow, adjacent wavelength bands • The energy in each band is measured by a separate detector. • Optics can be used before dispersion to adjust the ground resolution per pixel ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

12. Basic Working Principle www.microimages.com ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

13. Identification How can we identify materials? • Certain materials have a unique reflectance spectrum (i.e. plants have a high reflectance in the near-inferred range) • Spectral libraries can help identify materials • Hyperspectral imaging software can also help identify material From Hyperspectral Image Analysis Toolbox (HIAT) ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

14. Material Spectra Examples Notice soil follows a general curve, but moist soil has a lower reflectance. www.microimages.com ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

15. Soil moisture can be detected by the reflectance of the soil Below is a graph of soil reflectance with different moisture contents Material Spectra Examples “Hyperspectral Imaging for UAVs” ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

16. Hyperspectral Imaging Sensor Real-Time Images Frame-rate Small Computer BIL File Image Reconstruction Code Hyperspectral image Hyperspectral Imaging Software GPS, roll, pitch, yaw data Classification, spectra info etc. Sample Configuration Micro-Hyperspec Configuration ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

17. Specifications www.microimages.com Micro-Hyperspec ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

18. Limitations • There are few off the self Hyperspectral imagers available for aerial applications • Typically, the Hyperspectral Imager is application specific • Depends on wavelengths of interest and spectral resolution • Cost is high because the imager is typically a custom build and requires intensive calibration • Hyperspectral Images require either large bandwidth communication or memory ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

19. Alternatives • Panchromatic Imaging • Black and white image sensitive to all wavelengths • Multispectral Imaging • Similar to hyperspectral imaging • Contains less bands (less accurate) www.globalsecurity.org ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

20. Cost • Headwall Photonics • Galileo • Ocean Optics • P&P Optica • McPherson • Price ≈ $15,000 ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators