PHYS 115 PROJECT
Two boys are lost in deep woods in rugged te
ain. You are asked to employ your knowledge of infrared sensors to help out the state police with recommendations for the appropriate technology for a search. Please keep in mind that the boys were not ca
ying anything like cellphones and have been out for over 36 hours.
What you need to know to solve the challenge (key concepts):
Sensors (cameras) are available in several ranges of infrared – short wave, mid wave and long wave. They each have their own advantages for specific applications.
Background
Anticipated Search Area
The Park Rangers estimated that the hikers could be as far as 30 miles from when they were last seen in a parking lot. This is a huge search area, with:
Search_Area = Pi * Radius^2.
Search_Area = Pi * (30 miles)^2 = 2,827 square miles.
Characteristics of the Park Area
The park area is characterized by steep te
ain and heavily wooded regions. Steep ravines and creek beds make it difficult for individuals to cross in certain areas. Roads and various farms and rural villages may be within miles, but out of visual and audible range. As you can imagine, there is a lot of area to search and the potential for the hikers to be obscured by either te
ain or foliage from the search team(s). While this is a rural area with a small human population density, there are likely a thousand deer in the area, and thousands more smaller mammals. For this discussion we will define a "confuser" as any other mammal (or natural object) that may look like the hiker to the imaging system. For this example, at night there are likely to be several thousand more confusers than the two hikers in this region. It would be advantageous to have a sensor that could verify if the 'potential hikers" are indeed wildlife to save dispatching a human search team to each potential area.
3) Unmanned Aerial Vehicle (UAV) Assets
a) Viking 100 mid-sized UAV – Can handle a 20 lb. payload, with loiter time of up to six hours, and 65 knot airspeed. This can handle one of the mid-sized sensors that might be used as proposed in this project.
) Silver Fox – A small, lightweight UAV, with a typical airspeed of 40 knots, payload capacity of 5 lbs., and mission endurance of 8-10 hours. This could handle one of the smaller sized sensors proposed in this project. The lower airspeeds would be suitable for low-altitude flying in rugged te
ain.
Drone/Manned Aircraft Assets
Cessna 206 Manned Aircraft- Can handle a payload of greater than 400 lbs, with enough fuel to cover long duration missions. This airframe is sized to handle fairly large IR sensors, and could potentially overcome its mission requirements to fly at higher altitudes (to avoid the trees) with a high-sensitivity, na
ow Fieldof-View (NFOV) optical system.
Readily Available Imaging Sensors
Thermal sensor performance (MWIR and LWIR) is often characterized using the Night Vision Thermal Imaging Systems Performance Model, or NVTherm, developed by the U.S. Army. Sensors are described in terms of the range (distance) for target detection, recognition or identification. The target detection range is the distance at which a target is seen in the image as a small but detectable blur that wa
ants further investigation. The recognition range is the distance at which it is possible to distinguish among classes of objects, for example, to discriminate between a person and an automobile. This requires that at least a small cluster of pixels form the image. Finally, the image identification range indicates that a specific target can be identified, for example, a specific type of automobile.
Please submit the answers to the following questions BY DECEMBER 4:
What dangers could the lost hikers be facing while lost in the woods?
How could the dangers the hikers are facing affect your search techniques?
What is thermal infrared energy?
What is a micron?
What temperature does the average human have in Celsius? (A helpful hint for your work: humans usually have a temperature that is 1.5 degrees higher than any background temperature they are in.)
What kind of sensors could be use to locate the hikers? Are there other instruments that could be used to find the hikers besides sensors?
What considerations need to be taken when selecting a sensor for finding the hikers?