Super Pixel¶
The incoming front aperture radiance signal is given by three dimensional arrays
where,
\(\lambda\) are the wavelengths returned by the Front-End Radiance Generator
\(\Omega\) are the solid angles set by the
FOV.\(K\) i sthe number of samples set by the Platform measurement set.
Transfer Function¶
The transfer function, \(T(x,y,\lambda,\Omega)\) maps how much the incoming infinitessimal photon flux at wavelength, \(\lambda\) and direction \(\Omega\) at the front aperture contributes to the corresponding infinitessimal photon signal on the back-end detection plane at location \((x,y)\).
The transfer function is described in most systems by a suitable combination of instrument point spread function and spectral response function; a notable exception is for interferogram based systems where the transfer function is represented, to first order, by appropriate phasing of cosinusoidal signals.
The point spread function is normally determined by the quality of the optical design which is primarily driven by the level of optical aberrations within the system. The spectral response function is usually tied to the underlying optical technique used to measure signals and has more variation from instrument to instrument.
Nomenclature¶
Signal |
Units |
Symbol |
Description. |
|---|---|---|---|
radiance |
Photons/cm2/nm/sec/ster |
\({I}\) |
the average radiance over the field of view and wavelength bandpass. |
toa_albedo |
/ster |
\(\alpha\) |
top of the atmosphere albedo. Radiance divided by toa sun. |
irradiance |
Photons/cm2/sec |
\(E\) |
the irradiance signal per unit area integrated over the field of view and wavelength bandpass window |
photon flux |
Photons/sec |
\(P\) |
the photon flux integrated over the area of the front aperture, field of fov and wavelength bandpass |