- #1
ecastro
- 254
- 8
I stumbled upon this equation for a Lambertian uniform target:
##\rho^{*} = \frac{\pi L}{\mu_s E_s}##,
where ##\rho^{*}## is the reflectance, ##L## is the measured radiance, ##E_s## is the solar flux at the top of the atmosphere, and ##\mu_s## is the cosine of the sun zenith angle, ##\theta_s##.
The equation confuses me if I were to consider a monochromatic reflectance of the target, i.e. the reflectance of the target at a specific wavelength. What should be the measured reflectance for this case, is it the spectral radiance, should its units be ##\frac{W}{m^2 nm^2 sr}##? How about the solar flux (I considered it to be equivalent to the irradiance of the source at the target), should it be spectral irradiance, which I can calculate by the black-body radiation equation?
##\rho^{*} = \frac{\pi L}{\mu_s E_s}##,
where ##\rho^{*}## is the reflectance, ##L## is the measured radiance, ##E_s## is the solar flux at the top of the atmosphere, and ##\mu_s## is the cosine of the sun zenith angle, ##\theta_s##.
The equation confuses me if I were to consider a monochromatic reflectance of the target, i.e. the reflectance of the target at a specific wavelength. What should be the measured reflectance for this case, is it the spectral radiance, should its units be ##\frac{W}{m^2 nm^2 sr}##? How about the solar flux (I considered it to be equivalent to the irradiance of the source at the target), should it be spectral irradiance, which I can calculate by the black-body radiation equation?