Citation
Abstract
This article provides a model to estimate the effect of hot body noise on arrays of Deep Space Network (DSN) antennas using principles of communications systems and microwave radiometry. It provides approximations to calculate the increase in system noise temperature (or reduction in gain-to-noise-temperature ratio [G/T]) when the array tracks a spacecraft close to a source of microwave radiation. Through this analysis, we show that the array performance is not only driven by the main lobe of the array’s radiation pattern but also by grating lobes characteristic of arrays of widely separated elements. Using this model, we provide a way to classify sources of hot body noise as extended or compact and provide simplified expressions for the array performance in the case of very extended and very compact sources. We provide several numerical examples, including the noise temperature induced by Jupiter during a Juno flyby when the spacecraft was tracked by an array of three DSN 34-m beam waveguide antennas operating at X- and Ka-band.
Keywords
Details
- Volume
- 42-235
- Published
- November 15, 2023
- Pages
- 1–28
- File Size
- 3.6 MB