The integration of Remotely Piloted Vehicles (RPVs) into civil airspace will require new methods of ensuring traffic avoidance. This paper discusses issues affecting requirements for RPV traffic avoidance systems and describes the safety evaluation process that the international community has deemed necessary to certify such systems. Alternative methods for RPVs to perform traffic avoidance are discussed, including the potential use of new seeand-avoid sensors or the Traffic Alert and Collision Avoidance System (TCAS). Concerns that must be addressed to allow the use of TCAS on RPVs are presented. The paper then details the safety evaluation process that is being implemented to evaluate the safety of TCAS on Global Hawk. The same evaluation process can be extended to other RPVs and traffic avoidance systems for which thorough safety analyses will also be required.

A Safety Analysis Process for the Traffic Alert and Collision Avoidance System (TCAS) and See-and-Avoid Systems on Remotely Piloted Vehicles

The integration of remotely piloted vehicles (RPVs) into civil airspace requires new methods of ensuring aircraft separation. This work discusses issues affecting requirements for RPV traffic avoidance systems and for performing the safety evaluations that are necessary to certify such systems. The paper outlines current ways in which traffic avoidance is assured depending on the type of airspace and type of traffic that is encountered. Alternative methods for RPVs to perform traffic avoidance are discussed, including the potential use of new see-and-avoid sensors or the traffic alert and collision avoidance system (TCAS). Finally, the paper outlines an established safety evaluation process that can be adapted to assure regulatory authorities that RPVs meet level of safety requirements.

http://ieeexplore.ieee.org/iel5/9579/30281/01390836.pdf

Remotely piloted vehicles in civil airspace: requirements and analysis methods for the traffic alert and collision avoidance system (TCAS) and see-and-avoid systems

Students enrolled in “Underwater Acoustics and Sonar” at the Naval Academy benefit from a “hands‐on” demonstration of binary detection theory. The relationships between the respective probabilities of detection, miss, false alarm, and null [P(D), P(MISS), P(FA), P(NULL)] are examined for different thresholds. Two loudspeakers, driven respectively by random noise and a pure tone, simulate the acoustical environment. The output of a microphone is sent through an analog multiplier and a low‐pass filter, which act as the detector. An Apple IIe computer with a digital oscilloscope card displays the output and performs the probability density function on the processed signal. PDFs of (a) noise alone and (b) noise plus a signal are used to generate the receiver operating characteristic (ROC) curve. [Work supported by the Naval Academy Research Council.]

Classroom demonstration—Generating an ROC curve from the energy detection of signals in random noise

The integration of Remotely Piloted Vehicles (RF'Vs) into civil airspace will require new methods of ensuring aircraft separation. This paper discusses issues affecting requirements for RF'V traffic avoidance systems and for performing the safety evaluations that will be necessary to certify such systems. The paper outlines current ways in which traffic avoidance is assured depending on the type of airspace and type of traffic that is encountered. Altemative methods for RPVs to perform traffic avoidance are discussed, including the potential use of new see-and-avoid sensors or the Traffic Alert and Collision Avoidance System (TCAS). Finally, the paper outlines an established safety evaluation process that can be adapted to assure regulatory authorities that RPVs meet level of safety requirements.

Remotely piloted vehicles in civil airspace: requirements and analysis methods for the traffic alert and collision

: This report finds that a light weight, passive collision avoidance (PCAS) system based on uncooled LWIR sensors is feasible for Hunter/Predator class UAVs. The candidate PCAS system is analyzed using a statistical measure based on warning time provided. Typically warning times of 10s of seconds could be provided with very low probability of missed detection due to encounters with light aircraft under contrast reversal conditions.

/pdf/feasibility-of-a-passive-collision-avoidance-system-pcas-21djerja2u.pdf

R. G. Priest

Papers

Feasibility of a Passive Collision Avoidance System (PCAS) Based on Staring Infrared Sensors