No description available.

Note:

The Earth Radiation Budget Experiment (ERBE) is an operational system of radiometric instruments placed in Earth orbit by the National Aeronautics and Space Administration (NASA). Its purpose is to monitor those components of the Earth radiation budget which influence the weather and climate. The active cavity radiometer (ACR) instruments on board the ERBE satellites are periodically calibrated against internal standards and against the relatively well-known solar constant. In order to better understand the dynamic behavior of the instruments, a high resolution dynamic model has been developed and used to simulate the solar calibration. The instrument dynamic model consists of two elements: a radiation distribution factor model and a finite element model of the heat conduction process. The distribution factors, which lie at the heart of the simulation, distribute the thermal radiation incident to the instrument aperture over the diffuse-specular active cavity surface. The results of the model for a transient analysis during solar calibration are compared with two sets of operational data provided by NASA. Very acceptable agreement is found between the model results and the operational data. / Master of Science

In 1984, the Earth Radiation Budget Experiment (ERBE) was started by the National Aeronautics and Space Administration (NASA) to provide data to the meteorological community to predict long-term weather and climate trends. Three satellites employing nonscanning active cavity and scanning thermistor bolometer radiometers are orbiting the Earth to monitor its radiative emission. A numerical model has been formulated to better understand the performance of the ERBE scanning radiometer and to aid future radiometric design and calibration procedures. The Monte Carlo method is applied to the ERBE scanning radiometer to spectrally characterize its optical and radiative performance. The optical analysis reveals that the ERBE scanning radiometer design successfully limits the amount of energy that reaches the active sensor to the designated instrument field of view. Distribution factors between the diffuse-specular surfaces of the scanning radiometer are calculated using the Monte Carlo method and are then used to perform the radiative analysis. This analysis shows that less than three percent of the radiation emitted from the passive surfaces of the radiometer reaches the active sensor, an acceptable level for radiometric instrumentation used in space. / Master of Science

Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1979. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Stanley Richard Rotman. / B.S.

Thesis (M.S.)--University of Wisconsin--Madison, 1962. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 12).

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Part I. (1) An elementary treatment of the motion of charged particles in a magnetic field is presented. The concept of guiding centre motion is introduced, and is used in outlining the theory of particle drifts. (2 ) The motion of charged particles in the geomagnetic field is discussed, and the concept of adiabatic invariance introduced. (3) Mc Iliwains coordinates for mapping the distribution of charged particles trapped in the geometric field are defined and briefly discussed. (4) A survey of present knowledge of the Van Allen radiation zones is made. Particular attention is given to the distribution, characteristics, and variability of the trapped radiation. (5) The Cape Town magnetic anomaly, the Brazil radiation anomaly and the South Atlantic radiation anomaly are discussed. The electrons entering the South Atlantic radiation anomaly are shown to be those monitored over Iowa by the US satellite Injun I. Part 11. (1) It is shown how the geomagnetic field can, at high altitudes and over relatively short distances, be approximated by the field of a monopole. A new method is developed which enables one to plot the energy absorbed from an electron (which moves in a monopole field in the atmosphere) against altitude, given the initial energy and pitch angle of the electron. Some numerical computations using this method are described, and the results discussed. These results are used, in conjunction with US satellite Injun I for the Iowa region, to estimate the energy inout to the atmosphere in the South Atlantic radiation anomaly. The main approximations and simplifying assumptions made in this treatment, are discussed. (2) Geophysical effects generally recognized to be connected with the precipitation of charged particles are discussed. In the course of this discussion the two main theories of the connection between the radiation zones and the auroras are examined. (3) A preliminary discussion, based on the work summarized in point (1) of detectable geophysical events associated with the precipitation of electrons into the South Atlantic radiation anomaly is given. It is concluded that auroral emission, X-ray bursts, and ionospheric ionization in the E region should be more frequent and pronounced in the South Atlantic radiation anomaly than in any other region of comparable invariant latitudes and that the effects of atmospheric heating by precipitated electrons should be detectable over the anomaly. (4) An assessment is made of the value of the method referred to in point (1). Suggestions for its modification and extension are put forward. It is suggested that if more extensive rocket and satellite data on the low energy component of the electron flux become available, this method can be employed in a rigorous theoretical investigation of the South Atlantic radiation anomaly. Summary, p. 98-100.

The Earth Radiation Budget Experiment (ERBE) active-cavity radiometers are used to measure the incoming solar, reflected solar, and emitted longwave radiation from the Earth and its atmosphere. The radiometers are carried by the National Aeronautics and Space Administration's Earth Radiation Budget Satellite (ERBS) and the National Oceanic and Atmospheric Administration's NOAA-9 and NOAA-10 spacecraft. Four Earth-viewing nonscanning active-cavity radiometers are carried by each platform. Two of the radiometers are sensitive to radiation in the spectral range from 0.2 to 50 μm, while the other two radiometers are sensitive to radiation in the spectral range from 0.2 to 5.0 μm. Each set of radiometers comes in a wide-field-of-view (WFOV) and a medium-field-of-view (MFOV) configuration. The cavities of the shortwave (visible) radiometers are covered with a Suprasil® hemispherical dome to filter out the incoming longwave radiation. Knowledge of the optical and physical properties of the radiometers allows their responses to be predicted using a low-order physical model. A high-level, dynamic electrothermal end-to-end model which accurately predicts the radiometers dynamic output has also been completed. This latter model is used to numerically simulate the calibration procedures of the actual instruments. With calibration of the end-to-end model complete, a simulation of a phenomena referred to as the "solar blip" is conducted to investigate the instruments' responses to steep transient events. The solar blip event occurs when direct solar radiation is briefly incident to the active-cavity radiometric channels as the spacecraft passes into and out of the Earth's shadow. / Master of Science

Not available / text