Case Analysis Effectiveness

The case analysis project is a great assignment, that allowed me to formulate, organize, and deliver some suggestions on some important issues pertaining to the unmanned aircraft systems (UAS) operations. In my opinion, the case analysis paper presented a great approach to problem solving. It allowed me to analyze the problem, recommend alternate strategies, and select the most appropriate actions to mitigate the selected issue. The precise and direct problem statement allowed me to focus on a specific problem, such as UAS sense-and-avoid capability, without “overlapping” into other UAS issues. Consequently, the entire research project was dedicated to a particular problem. It allowed me to come up with concise alternative solutions to a particular issue. I found it helpful to review some examples of the problem statements online (Decker, n.d.).

The significance of the issue chapter helped me deliver an in-depth overview of the UAS sense-and-avoid issues. It allowed me to research the historical perspective of SAA capabilities of manned aircraft and apply this information to UAS operations. During my work on this chapter of the case analysis, I have also reviewed existing regulations pertaining to the UAS and specifically to sense-and-avoid capabilities.

The chapter on alternative actions allowed me to concisely select two appropriate migration strategies and describe their advantages and drawbacks. This helped me seamlessly flow into the formulation of recommendations for sense-and-avoid problem mitigation. I think, that the fact that we could be creative in our recommendations and express every idea we have in this chapter, was a great approach. It is very similar to “brain storming” used in problem solving. The ideas were not restricted by any existing limitations, which made it easier to express them. Of course, some of the recommendations may not be feasible to implement right away based on the current regulations and the current state of technology. However, it is possible that in the near future the opportunity to use some of these ideas will arise.

In my opinion, the case analysis approach would be beneficial in my current profession. First, as a pilot and aviation department manager, I frequently encounter situations when decisions have to be made in a timely manner. Often, we have a time constraints, budget constraints, regulatory constraints, which limit the possible decisions that can be made. However, we can always come up with several alternative courses of action, evaluate each advantage and drawback of these actions and elect the best approach.

I think this class was very informative and well structured. It presented us with a lot of valuable and current information on unmanned aerial systems. It not only included some of the technological, operational, and application aspects of the UAS, but also involved ethical, legal, and regulatory aspects as well. By providing peer reviews to other classmates’ posts, we also had an opportunity to learn and collaborate on different subjects. I think this interaction aspect of the class was very beneficial. Case analysis peer reviews were also quite beneficial. Since it allowed the students to exchange ideas and provide some recommendations for each other work.

In my personal opinion, writing and posting my discussions and blog posts as well as case analysis assignments before reading my classmates posts gave me a chance to really focus on forming my own ideas and solutions. However, peer reviews gave us an opportunity to expand our knowledge and see different outlooks on the same topics or issues.

Overall, I really enjoyed this class and the collaboration with our professor and classmates. Looking forward to the new semester. Good luck to all of you in your future endeavors.

Respectfully,

Elena

References

Decker, G. (n.d.). Formulating problem statement. Retrieved from http://www.personal.psu.edu/users/c/v/cvm115/proposal/formulating_problem_statements.htm

Request for Proposal

Natural disasters strike unexpectedly, often taking countless lives and causing significant economic impact on the affected areas. Time is a critical factor when it comes to the emergency recovery missions. Unmanned aerial systems (UAS) applications during disaster recovery missions offer many valuable advantages for the emergency personnel. UAS has been utilized in several search and rescue missions during hurricane recovery efforts (Nitti, 2011). The National Astronautics and Space Administration (NASA) together with National Oceanic and Atmospheric Administration (NOAA) employed a Global Hawk UAS to collect data on hurricane Matthew, which recently affected the east coast of the United States (Vanian, 2016). The Ikhana UAS was deployed during wildfires in California. It was collecting temperature data and mapping fire locations. This UAS transmitted fire spot information to multiagency management centers and emergency workers on the ground helping the firefighting operations (National Astronautics and Space Administration [NASA], 2010).

UAS can also serve as a communication relay or wireless “hot spots” in case of communication infrastructure damage in the area. In fact, Verizon has tested this application utilizing a UAS as a mobile hot spot for its cell phone network. This capability can help first responders communicate and have access to online resources. This technology is even more valuable in remote locations where the wireless is damaged or destroyed or even in areas that currently have wireless service. (Hamblen, 2016).

For this paper the author selected the UAS that can be used in hurricane recovery missions. First, let’s discuss some of the baseline and derived requirements for this type of UAS. The time line for design, development, testing, and deployment of this UAS would be approximately one year. The vehicle platform should be small enough to be easily transported to the disaster area and launched on the moment’s notice. It will require high definition still camera and video sensors to provide the recovery workers with complete picture of the area. The sensory payload would also include a thermal sensor and a night vision sensor to aid in location of stranded persons during poor visibility and low light operations. The UAS should be capable of providing imagery of the area supplemented with the GPS location tags for quick position reference. The vehicle should be able to withstand moderate wind gusts since it may need to be deployed immediately after storm passage. Therefore, the base and derivative requirements will include the following parameters:

1.     Air vehicle element shall be able to house all required systems, payload equipment, and provide sound aerodynamic flight capabilities.

1.1  The UAS shall be able to operate at altitudes of 300 feet above ground level.

1.2  The UAS shall be able to offer one-hour endurance.

1.3  The UAS shall be able to cover a range of 3 nautical miles.

1.4  The UAS shall be able to hover.

1.5  The UAS shall be hand launched.

1.6  The UAS shall be able to perform landing without requiring runway or approved landing area.

1.7  The UAS shall have a sufficient physical dimension to incorporate all required payload equipment.

1.8  The UAS shall be equipped with sufficient power system to sustain flight operations and support payload equipment.

1.9       The UAS shall be able to operate during wind speeds of 30 miles per hour.

1.10         The UAS shall be able to withstand wind gusts up to 30 miles per hour.

1.11         The UAS shall be able to be prepared for launch within 20 minutes.

1.12         The UAS shall feature a robust design for operations in the adverse weather condition.

1.13         The UAS shall have a waterproof design to protect the vehicle and sensors from the elements during operations in precipitations.

1.14         The UAS shall incorporate both autonomous and manual operational capabilities.

2.               Payload element. Payload sensors shall provide means for an area inspection and for victim location.

2.1 The Payload shall be capable of color motion video recording up to 300 feet.

2.2 The Payload shall incorporate an infrared (IR) sensor.

2.3 The Payload shall incorporate a thermal sensor.

2.4 The Payload shall utilize the main power system of the UAS.

2.5 The Payload shall be able to communicate acquired data via datalink to the ground control station (GCS) in real time.

 3. The communication (data-link) shall provide a robust connection between the UAS and the GCS. It shall enable The UAS to receive commands from the GCS and downlink sensory data and UAS status to the operator.

 3.1 It shall incorporate lost- link contingency procedures.

3.2 It shall be able to provide uninterrupted communication within a 3 miles’ radius.

3.3 It shall provide a means of real-time video transmission to the GCS.

3.4 It shall provide a means of still pictures transmissions to the GCS.

3.5 I shall provide real-time vehicle telemetry and “health” status.

3.6 It shall be powered by the UAS power system.

3.7 I shall accommodate a means of redundancy for the C3 systems.

Now that base and derived requirements are defined, it is important to discuss some of the testing requirements that can be used to validate and verify that base parameters have been met (Torun, 1999).

1.     Testing requirements.

1.1  Vehicle element

1.1.2 Test aerodynamic capabilities of the UAS using wind tunnel testing.

1.1.3 Test wind tolerance, gust tolerance during all cruise, takeoff, and landing conditions in the wind tunnel.

1.1.4 Test if the platform is waterproof using various precipitation levels.

1.1.5 Test the take-off and landing capabilities.

1.1.6 Test the hover/ orbiting capabilities of the vehicle.

1.1.7 Test that the vehicle platform will have sufficient space for all sensor payload and subsystems by physically incorporating each system into the vehicle.

1.1.8 Ensure proper center of gravity location.

1.1.9 Conduct manual flight testing in a real- world scenarios.

1.1.10 Conduct automated flight testing.

1.2 Payload

1.2.1 Bench test payload equipment to determine if the UAS power system will provide sufficient power for the payload operation.

1.2.2 Test various commercial-off-the-shelf (COTS) sensor options available and compare their size, weight, and power requirements.

1.2.3 Test the GPS data tags accuracy using predetermined locations on the ground.

1.2.4. Test the payload interoperability with C2 and the data-link subsystems.

1.3 Communications (data-link).

1.3.1 Test the communication range of the UAS in different geophysical setting, such as flat terrain, mountainous areas, hilly areas to determine how the topography will affect communications.

1.3.2 Assess lost-link procedures and vehicle performance during lost communication scenarios.

1.3.3 Test functionality of the redundant communication channels.

1.3.4 Test the procedure for switching to the redundant means of communication.

1.3.5 Test data uplink channel volume and speed of communications.

1.3.6 Test down-link channel volume of speed of communications.

1.3.7 Test if communication subsystem has sufficient power provided from the vehicle element.

Now, that testing requirements have been established, it is important to note, that the UAS test site may need to be reserved well in advance to enable on-time testing and ensure seamless transition between design, development, and testing phases of the project (Austin, 2010). It is important to develop a time line for the design project, that will include various stages of the design and the time allocated for each phase (Figure 1). It is advantageous to maintain a detailed record of any change made during the design process (Gurd, 2013). Traceability is extremely important, since even a minor change in any of the UAS sub-systems may affect other system design and may compromise the entire project (Austin, 2010). Also, it is imperative to assign specific tasks to each personnel to maintain accountability.  Each person must also define a level of authority thought the entire project to ensure a timely completion

Figure 1. The UAS project planner and timeline. This chart was created using a Microsoft Excel Gantt Chart.

Another important step is the UAS certification.  The appropriate regulatory agencies, such as the Federal Aviation Administration (FAA) should be contacted in the early stages of the UAS design. The assigned UAS company representative shall maintain close communication with the Agency in order to receive any feedback and incorporate any required changes into the design process to help speed up the certification process after project completion (Austin, 2010).

Since hurricane recovery missions are never standard, the UAS platform shall have a modular design that allows it to incorporate interchangeable payloads (Torun, 1999). It is advisable to use COTS products to meet this requirement. COTS products can present a significant advantage for designers especially in the selection of sensors and camera equipment. COTS will save time on development, and less expensive than customized payload design. Another advantage of modular design and the use of COTS systems is the possibility of future upgrades and further customization. As technology progresses and sensor capabilities improve, new payloads may be incorporated in the existing UAS platform.

As we can see, the UAS design process is a complex task, which requires careful planning, constant control, continuous adaptation to changes, and rigorous testing. After the UAS is built, tested, certified, and released to the customer, it will need to be supported, maintained, and possibly upgraded to maintain its efficiency, reliability, and safety. By carefully outlining the base and derivative requirements, including accountability, traceability and adhering to the timeline, the UAS project will be successful and produce a marketable product.

References

Austin, R. (2010). Unmanned aircraft systems. UAVS design, development, and deployment. West Essex, United Kindgom: John Wiley & Sons.

Gurd, A. (2013). Managing your requirements 101 – A refresher. Part 4: what is traceability? Retrieved from https://www.ibm.com/developerworks/community/blogs/requirementsmanagement/entry/managing_your_requirements_101_a_refresher_part_4_what_is_traceability7?lang=en

Hamblen, M. (2016). Drones could help in disasters like hurricane Matthew. Retrieved from http://www.computerworld.com/article/3128357/emerging-technology/drones-could-help-with-disasters-like-hurricane-matthew.html

National Astronautics and Space Administration. (2010). NASA’s Ikhana aircraft helps fight 1,000+ California fires. Retrieved from http://www.nasa.gov/offices/ipp/centers/dfrc/news_events/SS-Ikhana.html#.V_5SW4WcFPZ

Nitti, K. (2011). Unmanned aircraft offer new tools for the emergency response arsenal. Retrieved from http://www.emergencymgmt.com/disaster/Unmanned-Aircraft-Emergency-Response-032411.html

Torun, E. (1999). UAS requirements and design considerations. Retrieved from Turkish land forces command: http://ftp.rta.nato.int/public//PubFulltext/RTO/MP/RTO-MP-044///MP-044-B04.pdf

Vanian, J. (2016). NASA is flying a huge drone over hurricane Mathew. Retrieved from http://fortune.com/2016/10/07/nasa-drone-hurricane-matthew/

UAS law enforcement surveillance missions

Unmanned aerial systems (UAS) have been employed in a diversity of applications. Mission requirements and vehicle’s operational environment will largely influence the UAS design, payload, and flight envelope parameters. For the purpose of this paper, the author has selected the law enforcement surveillance applications of UAS. This research will identify the mission parameters, requirements, and challenges. It will also point out some legal and ethical concerns regarding UAS use for law enforcement. It will describe several suitable platforms and discuss their specific features that make them particularly advantageous for law enforcement missions.

Many law enforcement agencies use UAS on a daily basis. They are used in many missions to include tactical operations, criminal pursuit and crowd control. Their use has been expanded to include some non-conventional missions such as forensics and traffic management and also the more conventional rolls in search and rescue, and emergency services. This particular paper will focus on UAS law enforcement surveillance missions. Law enforcement surveillance can take place during suspect pursuits and property observation. Law enforcement can also use UAS for covert surveillance missions in order to collect evidence on suspected criminal or terrorist activity. The main requirements for a police surveillance UAS include:

-        Sufficient endurance and range to remain on station for an extended period of time, if required.

-        Easy launch and recovery capability to allow operations from the unimproved fields and congested areas. Use of vertical take-off and landing (VTOL) UAS platform may be preferred.

-        Quality camera sensor in order to produce high definition video and still images for evidence.

-        Low noise propulsion system to allow for covert surveillance missions if required.

-        Other sensors such as night vision, thermal, and infrared can be used for night operations.

-        Rugged platform, which is capable of operating in the adverse weather conditions, such as high winds and in both low and high temperature environments.

-        Vehicle’s operational safety. Safety of the officers and the civilians is the top priority. Choosing a reliable UAS platform will ensure that the wellbeing of persons on the ground and their property will be protected. It is important to incorporate safety and trouble-shooting features into the UAS to alert the UAS operator of any malfunction (Aerion, 2011).

For the purpose of this mission the author has selected three UAS platforms that can be used for police surveillance missions. The first UAS platform is the Qube made by the AeroVironment (Figure 1). The Qube features an easy control system and intuitive user interface. Weighting just 5.5 pounds, it is small enough to be easily transported in a police car and quickly launched on site (AeroVironment, n.d.). It incorporates advanced sensors, such as a high definition video camera and a thermal camera with zoom. This dual sensor suit will allow the UAS to acquire surveillance footage in both day and night conditions. The Qube has 40 minutes endurance and over half a mile range, which makes it suitable for short range surveillance operations (AeroVironment, n.d.).

Figure 1. The AeroVironemnt Qube. Adapted from “Qube,” by the AeroVironment, n.d. Copyright by AeroVironment.

The second vehicle is the Yuneec Typhoon H Pro UAS (Figure 2). It features a high definition CGO3+ 4K camera with a gimbal and a powerful real-time video transmitter, which is able to downlink video within a one-mile range, making it useful for law enforcement surveillance (Yuneec, n.d.). One great feature of this UAS is that in incorporates Intel® RealSense™ Technology, which allows it to navigate in confined environments, detect and avoid obstacles, while simultaneously following the operator (Homeland surveillance and electronics [HSE], n.d.). The Typhoon also has several flight modes, which can be preprogrammed before launch. These modes include journey, point of interest, follow me, and return home. The Typhon is a six rotor VTOL UAS. For additional safety, it can automatically switch to five rotor mode operations in case of a single rotor failure. The disadvantage of this vehicle is its limited range and restricted endurance. The battery on this UAS can only last around 25 minutes (Yuneec, n.d.).

Figure 2. The Typhoon with high definition camera. Adapted from “Typhoon UAS,” by Yuneec, n.d. Copyright by Yuneec.

The third option for surveillance applications is the Aeryon SkyRanger UAS. It has the longest endurance from all three represented vehicles. It is capable of staying aloft for up to 50 minutes. The SkyRanger features intuitive touchscreen interface and easy operation. It can be launched in the minutes’ notice and start simultaneously transmitting video and infrared imaging in real-time. It also can operate in the adverse weather conditions, such as high winds (up to 55 mph gusts) and extreme temperatures (-22F to 122 F) (Aerion, n.d.).

It features low-latency encrypted digital network, which enables simultaneous video streaming to multiple devices. It has the ability to include geotags and metadata along with images. The SkyRanger can operate beyond-line -of-sight with up to 3.1-mile range, keeping law enforcement personnel out of direct danger.

Figure 3. SkyRanger UAS. Adapted from “Aerion SkyRanger,” by Aerion, n.d. Copyright by Aerion.

The main benefit of UAS applications for law enforcement surveillance is keeping the law enforcement informed about criminal activity in real-time while keeping the officers out of direct danger. The UAS will greatly increase situational awareness and help prevent police ambushes. They can provide valuable surveillance on suspect’s location and let the police know if the person is armed. Law enforcement can benefit from the use of UAS for evidence collection, by inspecting difficult to access areas, while remaining undetected.

However, there are some issues with UAS use for surveillance that need to be discussed. These include ethical, legal, and moral considerations. First of all, police surveillance should take into consideration the citizens right for privacy. It is important to consider the circumstances when and if the warrant for evidence collection should be obtained prior to use of UAS. In some urgent cases, such as criminal standoff, there is not enough time to obtain a warrant. Therefore, in life-and death situations, police may choose to immediately launch a UAS to obtain the footage on suspect’s location and status.

UAS surveillance missions also can raise some ethical concerns. UAS can operate at much lower altitudes than manned aircraft. The vehicles can descend to window- level and record images inside of the person’s residence. Some UAS may operate virtually undetected due to their quiet propulsion and small size. All of these factors make people associate UAS with “spying” and cause concerns and even avid protests from private citizens. Balancing ethical considerations and legal aspects of the police surveillance is one of the major challenges law enforcement has to currently deal with in the use of UAS.

It is interesting to note, that some citizens have would resort to shooting down a police UAS if one overflew their property. According to a recent poll, almost fifty percent of Americans believe that they have the "right to destroy" a drone that flies over their property (Koebler, 2013). Approximately two thirds of Americans are concerned that the law enforcement drones will invade their privacy. Therefore, it is import to educate the general public on UAS benefits in order to gain acceptance for this new technology among the civilians.

At this time there is no lethally armed UAS used in law enforcement. In 2015, North Dakota passed a law, which approved the use of non-lethal weapons, such as rubber bullets, tear gas, and pepper spray on UAS (Reese, 2015). Although, lethally-armed UAS are still quite a distant future in law enforcement, it is important to consider the moral and ethical aspects of these kinds of missions.

Use of UAS in police surveillance applications can provide a valuable insight on criminal and terrorist activity and ultimately prevent crimes and save lives. UAS can offer a variety of benefits for law enforcement, while preserving lives of officers operating on the front lines. However, it is important to consider ethical, moral, and legal aspects of these types of missions. Proper legal framework should be established to help guide UAS use for surveillance. The general public should be educated on the benefits of UAS to increase public acceptance and to help law enforcement to fully explore its benefits of this emerging technology.

References

Aerion. (2011). Considerations in selecting a small UAV for police operations. Retrieved from https://www.aeryon.com/whitepaper/whitepaperpolice

Aerion. (n.d.). Aerion SkyRanger. Retrieved from https://www.aeryon.com/aeryon-skyranger

AeroVironment. (n.d.). Qube. Retrieved from http://www.avinc.com/uas/view/qube

Homeland surveillance and electronics LLC UAS. (n.d.). YUNEEC - Typhoon H Pro with Intel® RealSense™ technology. Retrieved from http://hse-uav.com/yuneec_typhoon_h_pro_detect_avoid.htm

Koebler, J. (2013, March 20). Senate weighs benefits, privacy concerns of domestic drones. U.S. News and World Report. Retrieved from http://www.usnews.com/news/articles/2013/03/20/senate-weighs-benefits-privacy-concerns-of-domestic-drones

Reese, H. (2015). Police are now using drones to apprehend suspects and administer non-lethal force: A police chief weighs in. Retrieved from http://www.techrepublic.com/article/police-are-now-using-drones-to-apprehend-suspects-and-administer-non-lethal-force-a-police-chief/

Yuneec. (n.d.). Typhoon UAS. Retrieved from http://www.yuneecuav.com/yuneec-drones/

Unmanned Aerial Systems in the National Aerospace System

The integration of the unmanned aerial systems (UAS) into the National Aerospace System (NAS) brings out the subject of maintaining operational safety. Several important topics pertaining to the safe UAS operations have been discussed in recent years. They include establishing regulatory standards for UAS, communication link security, operator training and currency, vehicle maintenance requirements, and privacy concerns. This paper will focus on the UAS traffic separation requirements in the NAS. This issue is directly connected to UAS operational safety, since potential air traffic collision may result in a loss of life of manned aircraft occupants and persons on the ground.

Air traffic separation considerations

The main difference between the UAS and manned aircraft is the absence of a human pilot onboard of UAS. Traditionally, the pilot at the controls of a manned aircraft is in charge to see-and-avoid the nearby air traffic when operating in the visual meteorological conditions (Federal Aviation Administration [FAA], 2013). When flying in instrument conditions, air traffic control (ATC) provides traffic separation to all manned aircraft under their control. Pilots also rely on traffic collision avoidance technology that is available in the cockpit (Ramasami & Sabatini, 2015). For line-of-sight UAS operations, the operator on the ground has the authority to see and avoid other air traffic. However, visual traffic detection may be complicated at night and in adverse weather conditions. When operating a UAS beyond-line-of-sight, the vehicle controller is responsible for avoiding other traffic by relying on visual information and other available technology. However, the UAS operator’s situational awareness may be limited due to the restricted field of view, control signal latency, and lack of visual cues (Lam, Boschloo, Mulder, & Paassen, 2009). These limiting factors may negatively affect the UAS pilot’s ability to see and avoid other traffic. Therefore, UAS separation from other aircraft should be based on sense-and-avoid (SAA) technology installed on board the vehicle. Additional traffic separation can be provided by ATC, which can issue traffic advisories and alerts. Instead of communicating with the UAS itself, ATC would provide this information to the operator located at the ground control station (GCS). The disadvantage of this method is the possible delay in the communications and delayed collision avoidance execution due to signal latency.

Sense-and-avoid considerations for different UAS groups

The UAS operational altitudes, speeds, and sizes vary considerably depending on the UAS group. Therefore, the SAA technology selection should be based on the specific characteristics of the UAS. There is no one-size-fits-all SAA system currently available to fulfill the SAA requirements for all groups of the UAS (Gageik, Benz, & Montenegro, 2015). For instance, the Traffic Alert and Collision Avoidance System (TCAS), which is presently widely employed in manned aircraft could potentially be used in UAS. However, the large size and excessive weight of current TCAS equipment may prohibit its usage on some lighter UAS. Some of the smaller UAS may also be difficult to detect visually by a manned aircraft pilot due to their size. For example, a pilot of a manned aircraft travelling at 300 knots may not have enough time to see, react and avoid a small UAS. Pilots who routinely scan and locate full sized aircraft may have a difficult time locating small UAS and this may result in mid-air collision.

Consideration should also be given to different airframe designs of the UAS. For example, lighter than air UAS may lack maneuverability when compared to fixed-wing aircraft and may be unable to execute the evasive maneuver in a timely manner. However, their large size makes them more visible and their slower speeds decreases their closure rate with conflicting traffic.  

 Current sense-and-avoid technology

The current technology employed by manned aircraft includes both the ground-based traffic detection and separation and the airborne traffic detection and avoidance technologies.  ATC employs radars to monitor and manage aircraft traffic. Current ATC radars feature clutter reduction technology to include only primary traffic detection. Due to their small size some UAS may not be displayed on the radar screen. Therefore, modifications to radar processing may be required to allow UAS detection by the ATC (Lacher, Zetlin, Maroney, Markin, & Ludwig, 2010). Another option is to design the UAS to be easier to detect both visually and on radar. This is just the opposite of military UAS that need to be stealthy and hard to detect. Commercial UAS operation in the NAS should be designed to be easily seen and detected on radar. Day glow reflective paints schemes for visual detection and the use of sharp angles and highly reflective materials for radar detection will make the job of detection much easier for both pilot and controllers.  

A Ground Based Sense and Avoid (GBSAA) capability especially developed by the U.S. Army for UAS. The GBSAA is designed for traffic separation in the busy airspace segments, such as terminal areas. However, ground based sense-and avoid has limitations and needs to be supplemented with airborne sense-and-avoid technology (Department of Defense [DoD], 2016). For example, ground based SAA is susceptible to signal latency and may not be usable during lost link scenarios.

The airborne sense-and-avoid technologies includes both cooperative and non-cooperative sensors. Cooperative sensors obtain radio signals from another aircraft to determine its position and altitude. Cooperative sensors include: transponders, Automatic Dependent Surveillance – Broadcast (ADS-B), Automatic Dependent Surveillance – Contract (ADS-C) (Ramasami & Sabatini, 2015). TCAS is also a cooperative technology employed in manned aircraft, which is based on the aircraft's transponder equipment. It provides the pilot with traffic information, automated traffic alerts, and smart conflict resolution advisories. The disadvantage of cooperative sensors for SAA is that cooperative technology will only function if all participating traffic is equipped with transponders (Lacher et al., 2010). ADS-B and ADS-C is based on the satellite surveillance. This technology does not require ground based interrogation by a radar. Currently, cooperative sensors are not required in all classes of airspace. (Delves & Angelov, 2012). Figure 1 depicts UAS SAA system.

Figure 1. SAA system diagram for UAS. Adapted from “MIDCAS sense-and-avoid” by MIDCAS, 2011. Copyright 2011 by MIDCAS.

Non-cooperative sensors passively acquire target information or actively emit energy to perceive the surrounding traffic. The non-cooperative SAA sensors will function even if other aircraft are not carrying similar equipment. Non-cooperative sensors include millimeter wave radar, electro-optical/ infrared, thermal, and acoustic sensors (Lacher, Maroney, & Zeitlin, 2007). Different sensors has their own advantages and limitations (Ramasami & Sabatini, 2015). A full description of these sensors go beyond the scope of this paper. Some researchers offer a sensor fusion approach for UAS SAA in order to satisfy collision avoidance requirements. Figure 2 depicts sensor data fusion schematic.

Figure 2. Sensor data fusion for SAA technologies and system process. Adapted from “A unified approach to cooperative and non-cooperative sense-and-avoid,” by S. Ramasamy, S., & R. Sabatini, 2015. Copyright 2015 by S. Ramasamy, S., & R. Sabatini.

This is just a brief description of available SAA technology. As we can see, there are a variety of SAA methods employed in manned aircraft. It is possible to use some of these traffic avoidance methods for UAS. The author would recommend employing ground based surveillance together with airborne sensors for UAS to ensure proper traffic separation in the NAS. However, due to size, weight, and power limitations of different UAS groups, there is no one universal airborne sensor available for SAA. Therefore, it is important to select appropriate sensor based on the unique characteristics and operational parameters of the UAS.  For added safety an automated collision avoidance and evasive maneuver execution will be necessary to make the SAA protocols effective. Automated traffic avoidance execution will be especially useful in case of loss of link. Similar to car that will apply the brakes themselves when no input from the driver is detected. A last line of defense avoidance maneuver should be incorporated.    

With fast technological progress, it is likely, that SAA capabilities will increase rapidly. Smaller, and more capable sensors together with ground and satellite based traffic separation methods will enable safe UAS operations in the NAS.

References

Delves, P., & Angelov, P. (2012). Sense and avoid in UAS: Research and application. In Sense an avoid (2nd ed.). Retrieved from http://www.ebrary.com

Department of Defense. (2016). Airborne based Sense and Avoid (ABSAA) sensor for tracking non-cooperative aircraft for RQ-7 Shadow and larger UAS. Retrieved from https://www.sbir.gov/sbirsearch/detail/870673

Federal Aviation Administration. (2013). Integration of civil Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) roadmap. Retrieved from http://www.faa.gov/uas/ media/uas_roadmap_2013.pdf

Gageik, N., Benz, P., & Montenegro, A. (2015). Obstacle detection and collision avoidance for a UAV with complementary low-cost sensors. Retrieved from http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=7105819

Lacher, A., Zetlin, A., Maroney, D., Markin, K., & Ludwig, D. (2010). Airspace integration alternatives for unmanned aircraft. Retrieved from http://www.mitre.org/sites/default/files/pdf/10_0090.pdf

Lam, T., Boschloo, H. W., Mulder, M., & Paassen, M. V. (2009, November). Artificial force field for haptic feedback in UAV teleoperation. IEEE transactions on systems, man, and cybernetics, 39, 1316-1331. Retrieved from http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=5263033&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D5263033

MIDCAS. (2011). http://www.midcas.org/News/News/Midcas-Flight-tests-press-release,i196.html

Ramasami, S., & Sabatini, R. (2015). A unified approach to cooperative and non-cooperative Sense-and-Avoid. Retrieved from http://ieeexplore.ieee.org.ezproxy.libproxy.db.erau.edu/xpls/icp.jsp?arnumber=7152360

Weeding out a solution

The design process is complex and requires extensive planning. The entire project can be compromised if problems are not found early in the design stage. It is important to identify possible issues within the project early in the design process to minimize risk of project failure and to avoid unnecessary costs and delays. A systems engineer’s responsibility is to manage the entire project. He will define derivative requirements based on customer needs and specifications. He will solve conflicts arising between the design teams and select the appropriate solutions. He will be responsible for the final product approval, launch, and support. It is a tremendous task, which can only be accomplished with careful planning, constant monitoring, and critical decision making.

The system engineer will have to take the role of mediator to solve conflicts between the two design teams. Sometimes the solution will require both teams to modify their systems in order to achieve a functioning end product (Loewen, 2013).

The current scenario describes the situation when an UAS system was built overweight. A major contributing factor to this issue is that the guidance, navigation, control and payload delivery system were all purchased from an outside vendor. This resulted in both systems going over their allotted weight budgets. This resulted in the inability of the UAS to carry a sufficient weight to spray a certain amount of fertilizer over the specified area without cutting into the fuel margin.

The customer is already expecting the UAS to meet certain performance requirements. Therefore, changing the system’s spraying capacity or range will potentially result in the customer cancelling its order and the entire project may be compromised. Therefore, we need to decide how we can change the UAS to accommodate the customers’ requirements and still be within the weight budget.

What are your considerations?

The primary focus in the systems engineering process are the project requirements. The entire project is focused on transforming the requirements into final product. The main idea is to fulfill these requirements within the constraints: limited resources, limited time, limited weight, etc. (Department of Defense [DoD], 2001). The requirement-based design is an approach which can be used to maintain “quality control” of the project and ensure that design team efforts match what the UAS must accomplish (Loewen, 2013). For this particular project it is important to consider the following:

1. We cannot cut fuel margin, since it will compromise the safety of the system and also reduce its range. Although, it may be possible to modify the power system to be more fuel efficient in order to provide longer endurance with the same fuel amount. However, this may result in significant increase in project cost and time required to complete the process.

2. We can custom design the payload delivery system and/or navigation, control, and guidance system. However, this option will also result in extra costs and time delays. However, certain modification may allow a decrease in size and weight of each system and, therefore, decrease overall gross weight of the UAS.

One solution is to modify the payload delivery (spraying) system by installing a pressurized fluid reservoir instead of electric motor driven pump. The pressurized spraying system will eliminate the need and weight of the motor, the pump and its wiring and hardware. This modification will also lower the overall power requirements for the UAS and save fuel. The reservoir would be filled and then pre-charged with compressed air to deliver the spray under pressure. Another solution is to modify the navigation, control, and guidance system by placing some required navigation and guidance subsystems in the ground control station (GCS) instead directly on the vehicle. It will also save weight and free up the extra space onboard.

3. We could find a different vendor for these system. It is possible to replace the control/navigation and guidance system with lighter off-the-shelf equipment. However, the availability may not be certain. Another concern is the safety and quality of the off-the-shelf products. Before making a commitment to purchase a system from the outside vendors, it imperative to review and verify its safety and quality characteristics.

4. We could increase a size of the UAS platform itself, this would allow it to house the existing systems.

5. We could incorporate lighter composite materials to help reduce the overall weight of the UAS.

6. We could compensate for weight increase by reducing the weight of other systems? For example, if we eliminate any redundant equipment, the UAS weight will be decreased. However, it is important to maintain certain level of redundancy to maintain operational safety.

What are your priorities?

First of all, we have to keep in mind the customer requirements. The entire project should be focused on creating a UAS, which will be able to carry out the customer specified mission. Another priority is to achieve the finished product within budget and with the time constraints. A quick time- to-market is another important consideration. Delays in production may hinder project success and allow competition to step in. Quality of the product is another priority. The product should be designed to be easily supported after release and throughout its lifecycle. It should be easy to maintain and, and if necessary, upgrade.  Of course safety should also be a major priority. Although, some may believe that since the system is unmanned, the levels of safety are not as important as with manned systems. However, it is imperative to keep in mind the safety aspect for UAS, considering that the vehicle may overfly populated areas and could easily become a hazard to personnel on the ground.

The systems engineer deals with solving conflicts between the design teams. The phase-gate approach can be used in systems development. This includes a periodic review of each system. The design team cannot continue past a certain point in the design process unless the corresponding review has been satisfactory completed. The review can be formal or informal (peer) review. Projects executed in a phase gate model have three main fundamentals: deliverables, criteria and outputs (Innotas, n.d.). Another important aspect to consider is traceability throughout the entire project. Traceability will ensure that each team is accountable for its design and this will allow the designers to trace their steps back to mistakes (Loewen, 2013). 

There are several steps in managing conflict: 

1. Explore the reasons for the conflict.

2. Find an alternate resolution for the disagreement.

3. Choose the most appropriate solution. 

4. Implement the solution.

5. Evaluate the solution (Rainey, n.d.).

This steps can be applied to any conflict. In this particular case, the system engineer will have to serve as the “mediator” between teams and recommend the best resolution.

 What do you think about the future prospects for the “next generation, enhanced” version of the system as a result of your approach?

It is important to keep in mind future missions for designed UAS. Maybe the customer requirements will change and an even larger spaying capacity will be required. It is also possible that a customer will add additional payload systems into the UAS, such as sensor and cameras for crop evaluation and monitoring. In this case, increasing size of the vehicle may be advantageous at this stage to allow for a larger payload capability in the future. Incorporating a modular design could be beneficial for future applications as well. It will allow the incorporation of “next generation” payloads without redesigning the UAS.

References

Department of Defense. (2001). Systems engineering fundamentals. Retrieved from http://ocw.mit.edu/courses/aeronautics-and-astronautics/16-885j-aircraft-systems-engineering-fall-2005/readings/sefguide_01_01.pdf

Innotas. (n.d.). Phase-gate approach project management. Retrieved from https://www.innotas.com/solutions-topic/phase-gate-approach-project-management

Loewen, H. (2013). Requirement-based UAS design process explained. Retrieved from https://www.micropilot.com/pdf/requirements-based-uav.pdf

Rainey, M. (n.d.). Resolving team conflicts. Retrieved from http://michaelrainey.com/pdf/NegTeamConflict.pdf

History of Unmanned Aerial Systems

Unmanned aerial systems came a long way since they were first introduced. The first UAS were merely small remotely controlled vehicles, which were simple, carried minimal payloads, and were often disposed of after completing their missions. Modern UAS incorporate sophisticated designs, use advanced navigation equipment, employ the latest technologies for control, command, and communications. They carry advanced modular payloads, have onboard data processing capabilities, and disseminate data directly to the users. They can stay aloft for extended periods of time and feature stealthy signatures. However, all of these technological advancements were acquired through the lengthy process of research, trials, and mistakes encountered during the early stages of UAS development. For the purpose for this research, the author has selected two UAS platforms, designed for similar missions of military reconnaissance. First vehicle- the SD-1 falconer represents an early UAS design. The second UAS, the Spy’Ranger is an example of a contemporary UAS design. 

Northrop /Radioplane SD-1/RP-71/MQM-57 Falconer

The Falconer was built in 1955 by Radioplane company, which later became knowns as Northrop (Western museum of flight, n.d.). The Falconer UAS evolved from target drones. This 13 feet long vehicle had a wingspan of 11 feet and weighed 430 pound (Figure 1).

Figure 1. The RP-71 Falconer UAS. Adapted from “Northrop SD-1/MQM-57 Falconer,” by A. Parsch, 2007. Copyright by via Ordway/Wakeford, n.d.

It was capable of speeds up to 185 miles per hour, operating at top altitude of 15000 feet. It was equipped with McCulloch O-100-1 72 horse power piston engine. This UAS had 40- minute mission endurance and range of 100 miles (Parsch, 2007). The Falconer primary mission was battlefield reconnaissance. It was equipped with a still picture camera. An optional TV camera was also available. For night missions, the Falconer used flares to illuminate the survey area.

Flight control was accomplished with an autopilot, which also had a radio-control backup. The Falconer was launched via rocket-assisted takeoff launcher and used a parachute recovery system for landing (RPAV, n.d.). 

The Falconer continued to be used by the military until the mid-1970s. A total of 1500 Falconers were built by Northrop. The next UAS was built to carry out the same missions as the Falconer, however, it uses the latest technological advancements to give the vehicle superior capabilities in military applications.

Spy’Ranger UAS

This mini- UAS was developed by Europe's leading UAS developer- Thales. The Spy’Ranger is a relatively small platform, which weighs only 55 pounds. It is constructed mainly out of carbon-fiber material, which gives the vehicle’s airframe strength and durability (Figure 2).

Figure 2. The Spy’Ranger UAS. Adapted from “Spy’Ranger, the fruit of collaboration between an SME and a prime,” by C. Mackenzie, 2016. Copyright 2016 by N. Gain.

The UAS can be disassembled for transportation and assembled on-site in less than 10 minutes (Mackenzie, 2016). Similar to the Falconer, this UAS was specifically designed to perform reconnaissance missions. This mini-UAS features an electro-optical/ infrared (EO/IR) sensor, housed on the gimbal, which gives a greater view of the survey area and allows the operator to focus the camera and sensor equipment on target during vehicle maneuvering. The Spy’Ranger is also capable of real-time target acquisition with a high-definition imaging sensor and a laser pointer. The Spy’Ranger is able to downlink the collected sensor information in real time, which is critical on the battlefield. The Falconer was lacking this important capibilty. The Spy’Ranger features a range of up to 18- miles and has 2.5-hour endurance (Thales, 2016).

 The vehicle is launched with a lightweight launch system, which is similar to the Falconer UAS. It can be setup in minimal time and can allows take-off in any direction. It only requires a small areas to launch and is capable of  all weather operations. The Spy’Ranger has an electric propulsion system, which gives the vehicle extra stealth capability. The Spy’Ranger can perform precise landings even in constrained areas. With help of specially designed software, the Spy’Ranger can calculate the best approach and landing taking into account wind and obstacle information. It features a landing cushion constructed from a Foam-Kevlar hybrid, which protects the vehicles during landings and helps absorb the shock (Thales, n.d.). The precise landing capability makes it easier to recover upon mission completion. The Falconer, on the other hand, could be difficult to locate after landing. The recovery parachute was greatly affected by the wind and in some cases, the Falconer was damaged while being dragged by the recovery parachute after touch-down or lost completely.

Another feature, which was not use in the early years of UAS is datalink protection. The Spy-Ranger uses a secure encrypted datalink, which prevent jamming and intrusion by an enemy.

As we can see, both of the described UAS were designed for reconnaissance. They feature similar size and weight characteristics. A similar catapult launch systems were used for both platforms. However, the materials used for airframe construction are more advanced in the Spy’Ranger UAS, comparing to the metal airframe of Falconer. New stealth characteristics are also taken into account with the use of an electric propulsion system on the Spy’Ranger. The real-time communication and datalink capability of the Spy’Ranger is crucial for today’s military applications. Datalink security is another priority for modern UAS operations, which was not a consideration in the early UAS designs.

UAS has been operating since World War II in the role of Surveillance and reconnaissance. They provide commanders with critical information on the battlefield. However, as we can see from two of these examples, the UAS technology has evolved significantly since the early years of UAS conception.  

References

Mackenzie, C. (2016). Spy’Ranger, the fruit of collaboration between an SME and a prime. Retrieved from http://forcesoperations.com/en/spyranger-the-fruit-of-collaboration-between-an-sme-and-a-prime/

Parsch, A. (2007). Northrop (Radioplane) SD-1/MQM-57 Falconer. Retrieved from http://www.designation-systems.net/dusrm/m-57.html

Remotely piloted aerial vehicles. (n.d.). Retrieved from http://www.ctie.monash.edu.au/hargrave/rpav_radioplane6.html

Thales. (2016). Sky’Ranger UAS: catch me if you can! Retrieved from http://events.thalesgroup.com/farnborough/en/article/762231/%20Spy-Ranger-mini-UAS-catch-me-if-you-can-

Thales (n.d.). Mini-UAV system for reconnaissance roles. Retrieved from https://www.thalesgroup.com/en/worldwide/defence/mini-uav-system-reconnaissance-roles

Western museum of flight. (n.d.). Northrop Radioplane RP-71 Falconer, SD-l. Retrieved from http://wmof.com/rp71falconer.html