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Modern battlefields depend on GPS for precision navigation and timing. Unfortunately, GPS signals are very-low level and GPS interference, both intentional and unintentional, can severely degrade GPS performance. Unmanned Aerial Vehicles (UAV), which have proven their value on the battlefield, rely heavily on GPS for navigation and flight integrity. Key to continued mission success for UAVs is enhanced anti-jamming capabilities. A revealing test of anti-jamming performance for a UAV is to maintain GPS synchronization, while accurately locating a GPS jammer. A small, modular ESM payload is needed to supply anti-jamming performance for the UAV and secondarily, to use DF techniques to locate the GPS jammer. This paper investigates a small, low-power, low-cost, modular solution to reducing the vulnerability to jamming of UAVs by leveraging commercial off-the-shelf technology. A miniaturized GPS antenna configuration that both lowers susceptibility to GPS jamming, and also allows accurate determination of the GPS jammer’s location, is presented. This GPS antenna arrangement consists of two GPS antenna arrays, one positioned on the top of the UAV (facing skyward) and one positioned on the underside of the UAV (facing the ground). The top antenna array acquires and tracks a minimum of 4 GPS satellites for accurate positioning and timing. The bottom antenna array is used to detect and locate GPS interference, and in coordination with the top array, limits susceptibility to GPS interference. The first action upon detecting GPS interference is to alter the reception pattern of the top GPS antenna array to reduce the amount of interference processed by the GPS receiver. Simultaneously, sampled data from both antenna arrays are used to monitor the effect of the interference and calculate the position of the jammer.

Unattended and tactical sensors are used by the U.S. Army’s Future Combat Systems (FCS) and Objective Force Warrior (OFW) to detect and identify enemy targets on the battlefield. The radios being developed as part of the Networked Sensors for the Objective Force (NSOF) are too costly and too large to deploy in missions requiring throw-away hardware. A low-cost miniature radio is required to satisfy the communication needs for unmanned sensor and munitions systems that are deployed in a disposable manner. A low cost miniature disposable communications suite is leveraged using the commercial off-the-shelf market and employing a miniature universal frequency conversion architecture. Employing the technology of universal frequency architecture in a commercially available communication unit delivers a robust disposable transceiver that can operate at virtually any frequency. A low-cost RF communication radio has applicability in the commercial, homeland defense, military, and other government markets. Specific uses include perimeter monitoring, infrastructure defense, unattended ground sensors, tactical sensors, and border patrol. This paper describes a low-cost radio architecture to meet the requirements of throw-away radios that can be easily modified or tuned to virtually any operating frequency required for the specific mission.

The Homeland Defense community is increasing its focus on port security and harbor protection. Rising to the challenge, the U.S. Coast Guard is tasked with monitoring and protecting our harbors where commercial container ships enter. Tracking of the onboard containers is of great concern to the protectors of the waterfront. A system capable of identifying the number of containers onboard the vessel, when the containers are added or removed, contents of the containers, etc., will significantly reduce the potential for a security problem by providing essential information to the Coast Guard or other port security so that they can decide whether or not pre-boarding is necessary. That is, boarding the ship and inspecting the cargo while still at a safe distance from the harbor. A conceptual pictorial of this concept is shown in Figure 1. This paper presents a system that utilizes transmitters embedded on the containers which incorporate unique ID codes identifying the container, its history, and other information. A Communication/Navigation Aid (C/NA) type vehicle/buoy concept, presently being developed by Sippican (under contract to the Office of Naval Research (ONR) as part of the Autonomous Operations -- Future Naval Capabilities (AO-FNC) program, positioned at sea, would include a payload of NuWaves’ communication transceivers able to receive the cargo container’s transmitted ID and forward this information by RF link to a ground station. The Port Authority and/or the Coast Guard would then utilize the information to make an assessment of the vessel prior to port entry. Although, this paper illustrates a scenario applicable to the cargo shipping industry, it is also applicable to other homeland defense areas such as unattended open ocean force protection, drug and law enforcement, and environmental monitoring.

As the war on terrorism continues abroad, the need to maintain security at home remains a major concern. Every aspect of the security effort can benefit from rapid information transfer. Advances in Commercial-Off-the-Shelf (COTS) radios make them valuable in applications ranging from deployed sensors on unsecured borders, to organizing an emergency response team. Additionally, the reduced cost and availability of these transceivers make them a viable alternative to custom developments. As an example, COTS radios can serve as the communication element in Unattended Ground Sensor (UGS) and munitions systems. Other applications include networked sonobuoys and networked RFID tracking. An additional advantage of COTS solutions is that they are available in a small form factor. They have extremely small mechanical outlines and are easily installed in systems requiring miniature designs and light payloads such as man-pack emplaced radios for the Army’s Future Combat System (FCS), as well as missions carried out by Unmanned Aerial Vehicles (UAV). The availability of the COTS radios result in a low-cost alternative for communication links that are applicable to military and Homeland Defense projects. They provide an easily obtainable, low-cost radio alternative enabling quick design cycles to meet mission timeliness. COTS solutions eliminate months from a typical design cycle and have many features already implemented such as ad-hoc routing and encryption. This enables robust hardware to be fielded quickly when a new need arises. The focus of this paper is to identify different COTS modules that can efficiently and cost effectively be applied to these and other various applications.