RIPCom Background

RSAC has been working with NASA Goddard Space Flight Center (GSFC) on adapting technology NASA has developed for unmanned aerial vehicles (UAV) to Forest Service applications. The Remote Internet Protocol Communication (RIPCom) system that is being developed by NASA-GSFC is of particular interest to the Forest Service because it can be used to download fire imagery during flight, which will save the Forest Service time and money while enhancing safety. RIPCom is a wireless communication system that makes any RIPCom equipped aircraft look like a network node in the sky. RIPCom provides an Ethernet to Radio Frequency (RF) connection solution for real-time data transmission, and its design allows the end points of the communication system to become nodes on a network with assigned IP address. RIPCom’s versatility makes it valuable for any system that requires a high-speed, digital wireless network.

NASA-GSFC has modified the original RIPCom design so that it meets Forest Service requirements. These include the ability to dump data at much faster rates and at greater ranges.

Specific Forest Service requirements include:

Fig. 1 - RIPCom Concept

• providing a wireless network connection at a distance of at least 10 miles
• supplying a data rate of at least 1 Mbps
• providing a long-distance wireless network that can also maintain a connection with a moving target
• design for aircraft that is 10,000 feet above-ground-level (AGL)
• data acquired at the ground station from an aircraft operating at 300 miles-per-hour (mph).

Fig. 2 - Detailed diagram

The RIPCom consists of COTS components from different vendors chosen because of their unique performance characteristics to meet Forest Service goals. Numerous wireless network technologies currently exist that are candidates for RIPCom, and many factors such as frequency, RF power output, size, and cost were considered for the Forest Service system design. The aircraft and ground station nodes were designed individually due to the unique conditions of each environment. Figures 1 and 2 illustrate the major components of the RIPCom concept and details of the system’s ground station and aircraft components.

Fig. 3 - View of the aircraft gain blade antenna

The major consideration for the airborne components is the antenna, which must be very aerodynamic while still providing a workable radiation pattern for this implementation. In addition, the antenna must be placed so that shadowing by the wings or other aircraft components is minimized. A 2.4 GHz, 5dB gain blade antenna (Figure 3) has been installed on the aircraft’s fuselage just aft of the forward landing gear bay, which gives the antenna an excellent field of view.

RIPCom’s ground station is designed so that it is able to provide bi-directional communication with a lower gain antenna 10 miles away. The ground station accomplishes this by utilizing a 3-sector, omni-directional antenna. The resulting system is able to provide a point-to-point connection for high-speed data transfer at an affordable cost ($7500 for the ground station, less tripod, and $3200 for aircraft station, less installation). Because RIPCom is platform independent, (it does not matter which operating system is used), the only requirement is that ground station and aircraft have a TCP/IP (Transmission Control Protocol/Internet Protocol) connection.