The discrepancy in annual changes of Earth albedo anomaly among the Had3CM prediction, ground and low Earth orbit
measurements attracts great academic attention world-wide. As a part of our on-going study for better understanding of
such discrepancy, we report a new earthshine measurement simulation technique. It combines the light source (the Sun),
targets (the Earth and the Moon) and a hypothetical detector in a real scale Integrated Monte-Carlo Ray Tracing (IRT)
computation environment. The Sun is expressed as a Lambertian scattering sphere, emitting 1.626x1026W over 400nm-
750nm in wavelength range. Whilst we are in the process of developing a complex Earth model consisting of land, sea
and atmosphere with appropriate BRDF models, a simplified Lambertian Earth surface with 0.3 in uniform albedo was
used in this study. For the moon surface, Hapke's BRDF model is used with double Henry-Green phase function. These
elements were then imported into the IRT computation of radiative transfer between their surfaces. First, the irradiance
levels of earthshine and moonshine lights were computed and then confirmed that they agree well with the measurement
data from Big Bear Solar Observatory. They were subsequently used in determination of the Earth bond albedo of about
0.3 that is almost identical to the input Earth albedo of 0.3. These computations prove that, for the first time, the real
scale IRT model was successfully deployed for the Earthshine measurement simulation and, therefore, it can be
applicable for other ground and space based measurement simulation of reflected lights from the Earth and the Moon.
In recent years, high performance visible and IR cameras have been used widely for tactical airborne reconnaissance.
The process improvement for efficient discrimination and analysis of complex target information from active battlefields
requires for simultaneous multi-band measurement from airborne platforms at various altitudes. We report a new dual
band airborne camera designed for simultaneous registration of both visible and IR imagery from mid-altitude ranges.
The camera design uses a common front end optical telescope of around 0.3m in entrance aperture and several relay
optical sub-systems capable of delivering both high spatial resolution visible and IR images to the detectors. The camera
design is benefited from the use of several optical channels packaged in a compact space and the associated freedom to
choose between wide (~3 degrees) and narrow (~1 degree) field of view. In order to investigate both imaging and
radiometric performances of the camera, we generated an array of target scenes with optical properties such as reflection,
refraction, scattering, transmission and emission. We then combined the target scenes and the camera optical system into
the integrated ray tracing simulation environment utilizing Monte Carlo computation technique. Taking realistic
atmospheric radiative transfer characteristics into account, both imaging and radiometric performances were then
investigated. The simulation results demonstrate successfully that the camera design satisfies NIIRS 7 detection criterion.
The camera concept, details of performance simulation computation, the resulting performances are discussed together
with future development plan.
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