Over-the-horizon radar (OTH), sometimes called beyond the horizon radar (BTH), is a type of radar system with the ability to detect targets at very long ranges, typically hundreds to thousands of kilometres, beyond the radar horizon, which is the distance limit for ordinary radar. Several OTH radar systems were deployed starting in the 1950s and 1960s as part of early-warning radar systems, but airborne early warning systems have generally replaced these. OTH radars have recently been making a comeback, as the need for accurate long-range tracking has become less important since the ending of the Cold War, and less-expensive ground-based radars are once again being considered for roles such as maritime reconnaissance and drug enforcement.

Bangor is a city in and the county seat of Penobscot County, Maine, United States. The city proper has a population of 31,753, making it the state's third-most populous city, behind Portland (68,408) and Lewiston (37,121). Bangor is known as the “Queen City.”