Abstract
This paper explores the typically ignored topic domain of unintentional GNSS RFI, as opposed to the more commonly documented maliciously generated RFI events, including jamming and spoofing. We begin by defining the numerous sources of unintentional RFI that have been encountered directly by the authors as well as those located through literature survey, then proceed to document examples of observations of the various families and source types of the unintentional RFI discussed. Based on the observations presented here, it is believed that unintentional RFI is presently a larger threat to L1/E1 band device operation than to the other GNSS frequency bands, but that trends in GNSS equipment itself may lead to the other GNSS frequency bands experiencing rapid increases in incidence rates of unintentional RFI over the coming decade.