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Your search keyword '"radiometer"' showing total 2 results
2 results on '"radiometer"'

1. TEMPEST-D Radiometer: Instrument Description and Prelaunch Calibration.

Author

Padmanabhan, Sharmila, Gaier, Todd C., Tanner, Alan B., Brown, Shannon T., Lim, Boon H., Reising, Steven C., Stachnik, Robert, Bendig, Rudi, and Cofield, Richard

Subjects
*MICROWAVE radiometers, *RADIOMETERS, *MODULATION-doped field-effect transistors, *COSMIC background radiation, *MONOLITHIC microwave integrated circuits, *LOW noise amplifiers, *CALIBRATION, *TROPICAL storms
Abstract

The Temporal Experiment for Storms and Tropical Systems Technology Demonstration (TEMPEST-D) instrument is a five-frequency millimeter-wave radiometer operating from 87 to 181 GHz. The cross-track scanning radiometer has been operating on a 6U CubeSat in low Earth orbit since September 5, 2018. The direct-detection architecture of the radiometer reduces its mass and power consumption by eliminating the need for a local oscillator and mixer, also reducing system complexity. The instrument includes a scanning reflector and ambient calibration target. The reflector rotates continuously to scan the antenna beams in the cross-track direction, first across the blackbody calibration target, then toward the Earth over the full range of incidence angles, and finally to cosmic microwave background radiation at 2.73 K. This enables precision end-to-end calibration of the millimeter-wave receivers during every 2-s scan period. The TEMPEST-D millimeter-wave radiometers are based on 35-nm indium phosphide (InP) high-electron-mobility transistor (HEMT) low-noise amplifiers. This article describes the instrument and its characterization prior to launch. [ABSTRACT FROM AUTHOR]

Published
2021
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2. Radiometer Design for the REACH 21cm Global Experiment

Author

Nima Razavi-Ghods, Ian Roque, and Will Handley

Subjects
Pipeline transport, COSMIC cancer database, Radiometer, Computer science, System of measurement, Pipeline (computing), Astrophysics::Instrumentation and Methods for Astrophysics, Calibration, Noise (video), Antenna (radio), Remote sensing
Abstract

Detecting signals from the Cosmic Dawn using “global” experiments requires an unprecedented level of instrumental calibration, especially to remove possible systematics which arise from the interaction between the antenna and receiving systems. In this paper we describe the calibration methods which can be applied to a range of experiments including the Radio Experiment for the Analysis of Cosmic Hydrogen (REACH) which is an instrument being designed to detect such signals. We use the functions described by noise wave parameters in a fast Bayesian pipeline to determine physical calibration coefficients which can describe the systematics. This approach when used in the field and on the fly could calibrate the absolute temperature measured by the antenna down to sub-kelvin levels. In this paper we present the Bayesian framework and simulated results of our pipeline using models derived from early laboratory measurements. A major advantage of this approach is that we can properly model the uncertainties in our measurement system.

Published
2021

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