Implementation Consideration for Automatic Dependent Surveillance - Broadcast on Unmanned Aircraft Systems

Abstract

There is increasing interest by the Unmanned Aircraft Systems (UAS) community in the technologies comprising Automatic Dependent Surveillance-Broadcast and its potential operational applications. However, there are significant weight, space, power and cost challenges to applying ADS-B to small UAS. The MITRE Corporation has been conducting research on ADS-B for many years and has recently been investigating applying ADS-B to small UAS. From this experience have emerged unique insights about the ADS-B technologies and considerations of interest to UAS and avionics implementers. This paper examines the technology, the key issues affecting weight and performance, and issues that impact UAS avionics costs. The views, opinions, and/or findings contained in this paper are those of the authors and The MITRE Corporation and should not be construed as an official Government position, policy, or decision, unless designated by other documentation. * Communications Engineer, F044, N570, and AIAA Member Grade for first author. † Communications Engineer, F044, N570, and AIAA Member Grade for second author.

Progress and future development toward a UAT ADS-B transmitter for space operations

“…The UBR-ERAU, advanced UAT ADS-B prototype based upon the MITRE UBR-TX ADS-B transmitter [1], addressed the technical limits impacting the UBR-TX and the majority of ADS-B units, which is the current limits on commercial offthe-shelf (COTS) GPS receivers and limits of the UAT message specification for maximum altitude and climb rates. Consumer GPS equipment sold in the United States is restricted to prevent operation at altitudes greater than 60,000ft or velocities greater than 1,000 knots as regulated in the International Trade of Armaments Regulations (ITAR) [5].…”

“…An advanced universal access transceiver (UAT) ADS-B transmitter payload was developed by Embry-Riddle Aeronautical University (ERAU) with funding from the FAA Office of Commercial Space Transportation (AST) and supported by both MITRE and the FAA William J. Hughes Technical Center. The ADS-B payload is based on the MITRE designed UAT Beacon RadioTransmit Only (UBR-TX) payload [1], that was designed for use by general aviation aircraft and UASs, but is capable of operating at greater altitudes and velocities through upgrades made to both hardware and software (See Figure 1). …”

Detect and Avoid for Small Unmanned Aircraft Systems Using ADS-B

“…While there is a significant amount of variation in the range of ADS-B signals, the shortest expected range is 10 nmi. Flight tests of ADS-B units suitable for small UAS have demonstrated reliable ranges of up to 80 nmi (Moody & Strain, 2009). Additionally the long range of ADS-B is advantageous in that the quality of information transmitted over ADS-B does not degrade with range.…”

“…Automatic Dependent Surveillance-Broadcast (ADS-B) is a cooperative sensor that is a promising option for DAA on small UAS. It has been demonstrated in small UAS flight testing to have an omni-directional range of 20 nmi (Moody & Strain, 2009), and due to the fact that the cooperative information is shared over radio waves it is relatively una↵ected by adverse weather conditions. An omni-directional antenna and low-power requirements for both transponder and receiver hardware contribute to the promising characteristics of ADS-B.…”

A high power fully integrated single‐chip CMOS transmitter for wireless communication of unmanned aircraft system

“…At present, the ADS‐B transmitter is fabricated with hybrid integrated circuits (HICs) in three different modules: phase locked loop (PLL) module, up‐converter (modulator) module, and the power amplifier (PA) module , which makes the system very large in size and expensive.…”