Scarab (SCAnner for Radiation Budget) Flight Model 1 (FM1) is a four channels scanning radiometer, launched in February 1994, with the same ERBE scientific mission. It worked perfectly during one year, aboard a Russian satellite, METEOR 3 N°7. Data were very consistent with ERBE results. Calibration of FM2 and Spare Model (SM) is described (one model will be launched aboard a Russian platform, RESURS, by the end of 1997). The calibration comprises three phases S solar/diffuser short wave source (will not be discussed in this article). blackbodies long wave sources under vacuum S integrating sphere short wave source Results are described and a comparison between the two last methods is established.
The speckle pattern in the image plane of the burst illumination imaging lidar system is characterized by the intensity correlation function. This speckle pattern, specific to coherent laser light, has two origins: the target roughness and the turbulence perturbation. We propose a model which takes into account both of them. For a non turbulent atmosphere, we find the classic speckle pattern given by Goodman. With a turbulent atmosphere, the perturbation along the forward and backward paths may be coupled or independent. In the coupled turbulence perturbation case, the collected intensity is amplified and the target scintillation is filtered by the receiver. For the independent turbulence perturbation case, the analysis is restricted here to a diffraction-limited atmosphere-lens system and two limiting cases are distinguished: the far-field and near-field assumptions.
This paper presents a model used to predict the performances of a burst illumination imaging lidar propagating through the atmosphere. The laser beam propagates near the ground on a long distance and undergoes strong perturbations due to atmospheric turbulences. This model takes into account both propagating paths: forward propagation as the wavefront progresses towards the observed object and backward propagation as the light is reflected back to the receiver.
We present here the MILORD project developed by the CERT for three years. MILORD is multiprocessor architecture organized around a 34 x 34 LCLV optical crossbar network, interconnecting 8 INMOS T414 microprocessors with 4 bidirectional links each and a ninth T414 host processor with 2 links on the network. This project intends to demonstrate the ability for optics to reach a higher degree of connectivity in parallel architectures.
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