Caption: Figure 1: Flowchart of the cloud-base height determination for one single sterical pixel ([T.sub.b] = brightness temperature, L = spectral radiance
, cs = cloudless sky, h = cloud-base height, and z = zenith angle) (see text for details).
Wildey, Establishing the Moon as a Spectral Radiance
Use of spectral radiance
for correcting in-season fertilizer nitrogen deficiencies in winter wheat.
(1996) demonstrated that total plant N could be estimated using spectral radiance
measurements at the red (671 nm) and NIR (780 nm) wavelengths.
As shown in Figure 2, the spectral radiance
of the flare versus wavelength can have a significantly different shape than that of the tracked aircraft, which has a much lower temperature.
A convenient technique to detect temperatures uses the spectral radiance
method whereby the IR radiation intensity at a given wavelength is converted into a temperature via Planck's law or Wien's law (17, 18).
Fortunately, atmospheric vapors have narrow line widths that allow the modulation of the AOTF to increase the sensitivity by obtaining first and second derivatives of the spectra, as shown in Figure 7 for a laser line with 1 percent of the spectral radiance
of a glow bar in the background.
On the basis of radiative transfer theory, under clear-sky conditions the spectral radiance
measured in the thermal infrared (TIR) band at the sensor level can be written as
Many researches on radiation balance with Landsat 5 and 7 images have used maximum (Lmax) and minimum (Lmin) radiances in the process of conversion of the gray level into spectral radiance
(Bastiaanssen et al., 1998; Allen et al., 2002; 2007; Silva et al., 2005b; 2011).
where B([lambda], T) is the blackbody spectral radiance
at the same temperature T.
A methodology for using a calibrated filter radiometer to measure and monitor the spectral radiance
of calibration sources is described.