Search and Rescue (SAR) is a practice done to salvage people from disasters. This practice is done by professionals who are specialized in particular disasters, for instance, following a hurricane or earthquake. These professionals serve to protect life to the best of their ability in each and every operation they encounter. As such, they need as much information before venturing into a potentially life-threatening disaster area. A mechanism is, therefore, required to provide all the necessary information to the SAR professionals. An excellent solution is this scenario would be an unmanned aerial vehicle that can record and relay real-time information of the situation on the ground. The real-time information provided to the rescue team can be used to formulate a plan of approach and priority of the rescue efforts.
It is unfortunate that the American Samoa region suffered an earthquake in the recent past. The disaster was the combination of an earthquake that escalated into a tsunami. The result of this was the loss of over 100 souls. What is more concerning was the major challenge faced by the SAR team to access the area and the victims in need of assistance. Noticeably, this was mainly due to inadequate information that hampered efforts of assessing routes to access the victims and plan of rescue.
The purpose of this essay is to recount the extent of the disaster, the severity of injury to locals, the prevailing conditions hampering rescue efforts and the solutions that a UAV can provide in the future should such a scenario present itself.
According to a report compiled by the Government of Samoa, the region is mainly composed of volcanic islands and a heavy ground cover of vegetation. The four islands are independent of one another and fall under the jurisdiction of the United Nations. It is home to approximately 200,000 people, 70% of whom reside along the shores of the four islands. Going by this information, therefore, given the irregular and hilly terrain, a direct line of sight (LOS) for communication with the UAV might be challenging. The 40-mile shoreline is rather flexible in terms of LOS to a limit: around obstructing objects (Marshall et al., 2016). The hilly sections and canyons exhibit areas characterized by obstructions. Also, the heavy vegetation cover makes it crucial to use Beyond Line of Sight (BLOS) type of UAV (Marshall et al., 2016). The assumption being that those who get the chance will retreat uphill in case of a tsunami: as was the case in the Samoan Islands according to a Red Cross report. Uphill is characterized by heavy vegetation cover hence the need for IR sensors. The rescue efforts may go into the night; therefore, a Forward Looking Infrared Camera (FLIR) would be appropriate in this case. It is equipped with thermo-graphic equipment that can accurately read heat signatures. Therefore, the UAV can easily pick out survivors in the dark, under rubble or the dense forest cover. Given the implications on time, the need for continuous real-time information for SAR workers below, the criteria for choosing a suitable will also be based on in its endurance in the air. In addition, the irregular terrain makes it impossible to navigate a UAV without onboard sensors to provide a warning on impending object collision. The nearest airport, Pago Pago International Airport, is on the Tutuila Island. The selection of UAV will, therefore, be specific to the parameters that best describe the island and the function for which it will be employed.
There are a few prevailing issues hampering SAR efforts. The cell towers will most likely be rendered unusable during a disaster. Radio communication available for five miles LOS: this will be used to effect LOS UAV communication. The hilly obstruction can be mitigated by increasing the number of console vehicles with on-board UAV control systems. The airport is unusable hence the need to have helicopter UAV available to first responders. Also, 70% of the population lives along the shore: this translates to more people on the water if a tsunami hits. The six fishing boats available can be used in collaboration with the helicopter UAV to begin rescue activity. The cloud cover can be mitigated by arming the medium and high altitude fixed wing UAV with the thermo-graphics payload.
A typical drone is defined by several features. For the purposes of the subject at hand and the parameters set, this discussion will focus mainly on the notable technology relevant to the case of Samoan disaster. As previously discussed, most of the people retreated uphill to seek refuge on higher ground away from the flooding at the shoreline. The first priority for rescue workers would be to assess their position in the affected area and the clusters of groups and their locations on the ground. A UAV can be used to accurately determine this information: identify the clusters of survivors and pinpoint their location. This UAV would have to be fitted with a thermal camera that can work to locate and identify victims. An example of a camera that can be used for these purposes would be an FLIR or an Electro-Optical/Infrared Camera (EO/IR). FLIR is designed as a sensor to show heat signatures from a long distance. EO/IR, on the other hand, is the kind of infrared sensor that can be adjusted for the purposes of identifying people on the ground. It is capable of homing in on the target with greater accuracy. Since a limited number of UAVs will be allowed in the air at any one time, two of those will have to carry a payload of EO/IR and FLIR. The FLIR will provide holistic picture while the EO/IR UAV will home in on specific targets of priority as directed by SAR teams.
During an emergency, the airport will be prioritized of flights taking out passengers from the island and victims being airlifted to referral hospitals. The two payloads composed of thermographic sensors will be fixed wing UAV. Therefore, the initial deployment will take quite a while. Therefore, a UAV that can take off vertically and assist first responders to the scene is important. A helicopter UAV will be used for this purposes. The MQ-8B Fire Scout is a helicopter UAV equipped with Brite Star II payload sensor. The MQ-8B has the capability to hover over an area of interest. The payload has been in use by the US Marine Corps in the ground and maritime operations. First responders will rush in to help victims in immediate danger of drowning. This helicopter UAV can be instrumental in identifying and hovering in place till help arrives at the victim(s). However, since the helicopter UAV is only capable of using LOS communication, a member of the SAR team must be responsible for controlling it during rescue efforts.
Regarding endurance, different UAVs offer varying endurance. At high altitudes, aircraft tend to spend relatively less fuel compared to medium or lower altitudes. Therefore, the fixed wing UAV operating at the highest altitude will carry an FLIR payload. The medium altitude fixed wing UAV will carry the EO/IR payload to pinpoint the location inferred by the former at high altitude. Lastly, two helicopter UAV will be needed to operate in the lowest atmosphere in tandem with SAR team. They can span approximately 2hours and therefore two will be required to be used interchangeably.
The long range fixed wing UAV at the highest altitude will be equipped with low-resolution forward-looking IR camera. In addition to this, it will be equipped with a geo-referencing payload on board to infer the position of targets on the ground. It will communicate with satellite to relay real-time IR video feed to ground crew. The medium altitude fixed wing UAV will also provide a real-time feed to ground crew. Two medium altitudes UAV can work in a grid pattern as rescue efforts progress. The payload will include an IR camera with an EO camera enslaved to it. In addition to GPS on board, this UAV will need a high-definition thermal camera to provide an excellent picture of thermal feed to the ground crew. Its geo-referencing will be more accurate hence a limited field of view: and it will be equipped with zooming and panning feature camera. Ground control vehicles can be set up in areas of proximity. Inaccessible areas by vehicle can be accessed by single individuals moving with the console.
Therefore, five UAVs in total will be recommended for acquisition by the Government of Samoa. Of these UAVs, there will be two different types, the fixed wing and the helicopter UAV. The helicopter UAV, two of them, will be available to the search and Rescue team on site. The two helicopter UAV will be launched immediately to assist in rescue efforts of victims in the water. The medium and high altitude fixed wing drones can be deployed at the nearest airport in the Samoa region. One fixed wing UAV can be launched by departing planes to the higher atmosphere to identify clusters of thermal imaging on the ground relayed to SAR teams. The second can be launched to a medium altitude. The fixed wing UAV in the highest altitude will be autonomously controlled by satellite, whose permission can be granted by the FAA through the UN: since the UN has jurisdiction over the area. Likewise, the permission to use the airspace can be granted through similar channels. The high altitude fixed wing has a longer endurance and will carry an FLIR payload for observing and identifying payload on the ground. This information can be communicated through a ground console which, dependent on the recommendation of the SAR team, can direct the second UAV to areas of priority rescue. The third UAV can be used to facilitate the rescue of victims from water and under rubble by hovering directly over heat signature. The UAV at high altitude can endure but cannot provide accurate location of target better than the medium altitude fixed wing whose field of view is specific and therefore limited holistically. This is tackled by the lower altitude helicopter UAV, which has the ability to hover over specific victims in needs of rescuing.
References
Cox, T. H., Nagy, C. J., Skoog, M. A., & Somers, I. A. (2004). Civil UAV Capability Assessment. National Aeronautics and Space Administration.
FLIR. (2011). Unmanned Systems: DEVELOPED FOR AIRBORNE, LAND & MARITIME APPLICATIONS. Boston, Massachusetts , United States of America.
Government of Samoa. (2010). Tsunami. Pago Pago: Government of Samoa.
International Federation of Red Cross and Red Cresent Societies. (2011). Samoa: Earthquake and Tsunami. International Federation of Red Cross and Red Cresent Societies.
Marshall, D. M., Barnhart, R. K., Hottman, S. B., Shappee, E., & Most, M. T. (2016). Introduction to Unmanned Aircraft Systems. New York: CRC Press.
Nationa Park of American Samoa. (2016). Directions. Retrieved June 19, 2016, from Nationa Park of American Samoa: https://www.nps.gov/npsa/planyourvisit/directions.htm
