An Instrument Error Budget for Space-Based Absolute Flux Measurements of the Sky Synchrotron Spectrum Below 20 MHz

TL;DR

This paper develops an error budget model for space-based measurements of the sky's synchrotron spectrum below 20 MHz, focusing on electrically short dipole antennas and analyzing various error sources.

Contribution

It introduces a comprehensive error budget framework combining Monte Carlo and analytical methods for space-based low-frequency radio measurements.

Findings

Stray capacitance significantly impacts measurement accuracy.

The error budget model is adaptable to various space-based radio experiments.

Analytical and Monte Carlo methods provide consistent error estimates.

Abstract

This work describes the instrumental error budget for space-based measurements of the absolute flux of the sky synchrotron spectrum at frequencies below the ionospheric cutoff (<20 MHz). We focus on an architecture using electrically short dipoles onboard a small satellite. The error budget combines the contributions of the dipole dimensions, plasma noise, stray capacitance, and front-end amplifier input impedance. We treat the errors using both a Monte Carlo error propagation model and an analytical method. This error budget can be applied to a variety of experiments and used to ultimately improve the sensing capabilities of space-based electrically short dipole instruments. The impact of individual uncertainty components, particularly stray capacitance, is explored in more detail.