Contents

%%% moon.m computes detected signal in a pixel of moon image
% by Chuck DiMarzio
%    Northeastern University
%    June 2009
%

Compute spectral radiant exitance and spectral photon exitance at 5000K

bbd.m returns spectral data.

 [wavelr,mrlambda,wavelv,mvlambda,wavelp,mplambda,m,mv,mp,X,Y,Z]=...
     bbd(5000,0.35,10);
close all;  %  Close figures generated by bbd
fig1=figure;plot(wavelr,mrlambda/m,wavelr,mplambda/mp);
xlabel('\lambda, Wavelength, \mu m');
ylabel('f_\lambda, \mu m');
moose=axis;axis([moose(1),3,moose(3:4)]);
grid on;
---------
Temperature = 5000 Kelvin
Wavelengths from 0.35 to 10 micrometer
 
Peak Spectral Radiant Exitance, m_\lambda = 4.026e+07 Watts/m^2/micron at \lambda = 0.58 microns
Radiant Exitance, M = 3.433e+07 Watts/m^2 = 0.9678 of total in 0 to 100 microns
---------
Luminous Exitance, Mv = 2.888e+09 l/m^2
Chromaticity, x = 0.34508
              y = 0.35161
              z = 0.30331
Luminous Efficiency, 84.12 lumens/W
---------
Photon Exitance, Mp =1.855e+26 Photons/sec/m^2
Photon Efficiency, 5.402e+18 Photons/sec/W
                   6.422e+16 Photons/sec/lumen

Compute Conversion factor photons per joule

opticalpower=3.8e-12;
photons_per_joule=mp/m
test=wavelp<0.750;   %  Cutoff filter:  count just the ones in band
fraction_in_band=sum(mplambda(test))/sum(mplambda)
photons_per_second=photons_per_joule*opticalpower*fraction_in_band
photons=photons_per_second/30
photons_per_joule =
   5.4023e+18
fraction_in_band =
    0.2152
photons_per_second =
   4.4180e+06
photons =
   1.4727e+05