1. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-1 ECEG287 Optical Detection Course Notes Part 2: Radiometry Profs. Charles A. DiMarzio and Stephen W. McKnight Northeastern University, Spring 2004

2. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-2 Topic Outline Radiometric Quantities and Units Radiance Theorem Black-Body Spectrum Some Radiance/Irradiance Values A Little about Color

3. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-3 Radiometric Quantities

4. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-4 Radiometry and Photometry , Flux M, Flux/Proj. Area I, Flux/  L,Flux/A  E, Flux/Area Rcd. Radiant Flux Watts Luminous Flux Lumens Radiant Exitance Watts/m 2 Luminous Flux Lumens/m 2 =Lux Radiance Watts/m 2 /sr Luminance Lumens/m 2 /sr 1 Lambert= (1L/cm 2 /sr)/  1 ftLambert= (1L/ft 2 /sr)/  1mLambert= (1L/m 2 /sr)/  Radiant Intensity Watts/sr Luminous Intensity Lumens/sr 1 Candela=1cd=1L/sr Irradiance Watts/m 2 Illuminance Lumens/m 2 =Lux 1 Ft Candle=1L/ft 2 Notes: Spectral x=dx/d or dx/d : Add subscript or , divide units by Hz or  m. 1 W is 683 L at 555 nm.

5. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-5 The Radiance Theorem 11 22 n1n1 n2n2 dA d1d1 d2d2

6. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-6 Radiance in Images dA’ d1d1 d2d2 dA 1 dA 2 z

7. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-7 Resonant Cavity Modes

8. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-8 Resonant Frequencies in Cavity nxnx nznz nyny

9. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-9 Counting the Modes nxnx nznz nyny

10. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-10 Energy per Mode (1)

11. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-11 Energy per Mode (3)

12. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-12 Total Spectral Energy

13. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-13 Black Body Radiance (1) A A’

14. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-14 Black Body Radiance (2) A A’

15. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-15 Spectral Radiant Exitance (1) x y z   dd dd

16. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-16 Spectral Radiant Exitance (2)

17. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-17 Black-Body Equation (1)

18. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-18 Black Body Equations (2) T=300k 500 1000 2000 5000 10000

19. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-19 Solar Irradiance on Earth 0200400600800100012001400160018002000 0 500 1000 1500 2000 2500 3000 Data from The Science of Color, Crowell, 1953, Wavelength, nm E, Spectral Irradiance, W/m 2 /  m Exoatmospheric filename=m1695.m Sea Level 5000 K Black Body Normalized to 1000 W/m 2 6000 K Black Body Normalized to 1560 W/m 2

20. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-20 Typical Outdoor Radiance Levels Visible Near IR Mid IR Far IR Atmospheric Passbands Ultraviolet

21. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-21 Thermal Imaging  M /Delta T 10 10 0 1 2 0 0.5 1 T = 300 K 10 10 0 1 2 0 2 4 6, Wavelength,  m  M /Delta T T = 500 K

22. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-22 Luminance and Radiance 400500600700800 0 1 1.8 Wavelength, nm Photopic Sensitivity y This curve shows the relative sensitivity of the eye. To convert to photometric units from radiometric, multiply by 683 Lumens Per Watt

23. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-23 Some Typical Luminance And Radiance Levels

24. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-24 Emissivity

25. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-25 Color: Tristimulus Values Wavelength, nm Tristimulus Value Describe Eye’s Response to Color Based on Color Matching Experiments Small Number of Observers Lines are Approximations 300350400450500550600650700750800 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 z y x

26. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-26 Characterizing Colors 400500600700800 0 1 1.8 Wavelength, nm Tristimulus Value z x y Object Spectrum x y

27. Jan 2004 Chuck DiMarzio, Northeastern University 10464-2-27 Recording and Generating Color Images Camera with Three Filters Display with Three Sources Eye Object Three Separate Registered Images