Microwave photonic radiometry for atmospheric sensing
Date
2022
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Delaware
Abstract
For several decades, microwave sounders have made significant contributions to the atmospheric models which impact weather forecasting. By observing earth from satellites, passive microwave instruments sense the radiation emitted by common atmospheric constituents, such as oxygen and water vapor. Through these observations, scientists can determine the humidity and temperature profiles which are the drivers for accurate weather forecasts [1]. Furthermore, microwave radiometers can operate on the ground to generate a continuous stream of atmospheric data for one location. ☐ In this work, a new ground-based microwave radiometer architecture is developed and implemented using microwave photonics. A fiber-based arrayed waveguide grating (FAWG) is used as a dispersive optical element to detect the microwave spectrum over a 25 GHz bandwidth near the oxygen absorption line. An RF front end is developed and combined with an optical back end which utilizes active phase control to account for perturbations in the fibers. This work demonstrates that the microwave photonic approach is a viable method for radiometry and can produce a hyper-spectral result with significantly denser spectral sampling than conventional microwave radiometers. The approach validated here could be developed further to produce a space-ready microwave radiometer capable of collecting new information to further our understanding of the atmosphere.
Description
Keywords
Arrayed waveguide grating, Atmospheric sensing, Fiber optics, Microwave photonics, Radiometer, Remote sensing