James Randa

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—We report on the characterization of blackbody target reflections as part of the recent progress on the development of brightness temperature standards for microwave remote sensing at the National Institute of Standards and Technology. The very low reflections from the blackbody targets used in airborne or satellite remote sensing systems present(More)
Certain commercial entities, equipment, or materials may be identified in this document in order to describe an experimental procedure or concept adequately. Such identification is not intended to imply recommendation or endorsement by the National Institute of Standards and Technology, nor is it intended to imply that the entities, materials, or equipment(More)
1. ABSTRACT Accurate characterization of the brightness temperature (T_B) of black-body targets used for calibrating microwave remote-sensing radiometers includes many inputs: antenna pattern and loss, target temperature, target emissivity, mechanical alignment, and radiometric T_B measurements calibrated against physical standards. Here we describe(More)
—The NIST Noise Project has developed the theoretical formalism and experimental methods for performing accurate noise-temperature measurements on a wafer. This report summarizes the theoretical formulation and describes the design, methods, and results of tests performed to verify our ability to measure on-wafer noise temperature. Several different(More)
—We report our recent progress toward the development of microwave brightness-temperature (BT) standards. As one of the crucial parameters, the target illumination efficiency (IE) was traditionally determined from the relative antenna pattern. We propose a measurement technique to extract the target IE solely by the use of passive radiometric measurements(More)
1. ABSTRACT After an interlude of several years, NIST has recently resumed efforts to develop a primary standard for microwave brightness temperature. The previous work is summarized in [1]. Currently the principal effort [2] is to develop a standard radiometer, traceable to fundamental primary noise standards, but we are also taking steps toward(More)
—We present a geometric error model associated with calibration-target misalignment in passive microwave remote sensing systems. The developed analytic formulation is universally applicable to both lateral and rotational misalignment conditions. Numerical simulations are performed on two practical blackbody targets of different sizes used as radiation(More)