Unmanned Aerial Systems Mission Planning
Introduction
Unmanned Aerial Systems (UAS) constitute a wide variety of remotely controlled aerial systems, ranging from fixed-wing, single-rotor, and multi-rotor aerial vehicles (Colomina and Molina, 2014; Military Factory, 2015). The versatility of these systems allow for a plethora of uses from helping with precision agriculture, to 3D mapping, to helping with search and rescue efforts (Handwerk, 2013). UAS's have been around for quite some time now and were originally developed for use as military reconnaissance. In recent years, focus has shifted from only using unmanned aerial systems for use in military operations to recreational and commercial use. A multitude of technology exists to outfit these UAS systems for the multitude of tasks they will be used for. Certain cameras and sensors that can be put on the aircraft have different capabilities (Colomina and Molina, 2014). These different sensors can see in different spectral ranges, spectral bands, thermal sensitivities and visible band resolutions (Colomina and Molina, 2014). Armed with this knowledge, it will be possible to assess a number of different scenarios and determine the best way to use unmanned aerial systems to solve the issues presented.
Scenario 1
A power line company spends lots of money on a helicopter company monitoring and fixing problems on their line. One of the biggest costs is the helicopter having to fly up to these things just to see if there is a problem with the tower. Another issue is the cost of just figuring how to get to the things from the closest airport.
In the situation provided above, a rotary wing UAS, such as the Draganflyer S6, would be the most fitting to complete this task (Figure 1). The S6 retails for $8995 per unit and comes equipped with a Sony QX100 digital camera with HD live stream video capabilities.
 |
| Figure 1. This shows an example of a rotary wing UAS. There are four rotors on this aerial system, improving maneuverability, stability, allowing for direct vertical or horizontal movements, and allowing for the ability to hover (Draganfly.com). |
Rotary wing systems have a number of strategic advantages over fixed wing systems that make rotary wing systems better for this type of a job. The rotary wing system is able to move vertically and horizontally as need be and are also able to maneuver with greater agility than the fixed wing counterparts (UAV Insider, 2013). However, there are a number of questions that would need to be asked before a decision was made.
- What is the necessary flight range?
- What is the necessary flight duration?
- What weather conditions can be expected?
Rotary wing systems are more mechanically advanced than fixed wings, leading to shorter flight ranges and lower speeds (UAV Insider, 2013). If the distance of flight is too great, a rotary wing system will possibly not be able to accomplish the task because it will be out of range or the amount of battery will not be great enough to finish the mission. Weather is also a constant factor to be wary off with UAS's, as they are small and are susceptible to being pushed around by wind higher in the sky.
If all necessary conditions are met, the next steps will be to decide on the proper equipment for the job. In this case, sensors will not be a necessary piece of equipment, because only items within the visible spectrum need to be examined. A good camera that will be able to relay live feed video back to field headquarters station will be a necessary piece of equipment. This will allow the fliers to see where the downed lines are and record information that will allow others to know where to go and what the issues may be to fix the lines.
A number of live feed cameras exist that are mountable on UAS's. One particular camera, the Sony QX100, retails for $1595 (Figure 2). The Sony QX100 is gyro stabilized, easily mountable to a UAS, and transmits a live feed that can be synced to a smart phone with a Sony app, allows the user to control the zoom, and allows the user to trigger the shutter. The Sony QX100 has a 20 Megapixel lens, effective resolution of 5472 x 3649, and video resolution of 1440 x 1080 (Draganfly.com).
 |
| Figure 2. This camera is mountable on a UAS and provides live feed to a smart phone and the ability for the smart phone user to control the zoom and shutter (Draganfly.com). |
This equipment should provide the necessary equipment to properly monitor the power lines for damage and provide a visual avenue to remotely assess the damage.
Scenario 2
A pineapple plantation has about 8000 acres, and they want you to give them an idea of where they have vegetation that is not healthy, as well as help them out with when might be a good time to harvest.
Given the study area in the situation provided above, a fixed wing UAS would be the most fitting to complete this task (Figure 3).
 |
| Figure 3. This shows a fixed wing system being launched. The Falcon system can carry a payload of 2 lbs, making it perfect for the equipment that will be explained. It also is able to travel long distances and has over a 3 mile range, making it a prime candidate for this type of mission (Falconunmanned.com). |
A fixed wing provides longer flight durations and higher speeds that make this system better equipped for large areas, however it does require a runway for takeoff and landing, unlike the rotary wing system. The fixed wing in Figure 3 is the Falcon, retailing for $12000.
A number of questions should be addressed to better determine if unmanned aerial systems provide a viable option to assist the needs of the pineapple plantation.
- What is the potential cause of the unhealthy vegetation?
- What time of year is it?
- What have current weather conditions been like?
The factor that will be examined is the Normalized Difference Vegetation Index (NDVI), which essentially determines the density of green in a certain area (NASA EO). Healthy green plants absorb wavelengths in the visible spectrum and reflect wavelengths in the near infrared spectrum. Unhealthy plants with less chlorophyll are not as able to absorb the visible spectrum wavelengths and instead take in more of the near infrared spectrum. (Figure 4 and Figure 5).
 |
| Figure 4. This shows the electromagnetic spectrum from ultraviolet wavelengths to far infrared wavelengths (Vividlight.com). The two wavelength ranges necessary from this study are the visible light range and the near infrared rage. The visible range will be used to monitor the color of pineapples as they grow. The near infrared spectrum will be used to calculate a NDVI index. |
 |
| Figure 5. This shows the amount of absorption of the visible and near infrared light spectrums (NASA EO). The health vegetation on the left absorbs mostly visible light, reflecting roughly 8% of it, while reflecting 50% of the near infrared light. The unhealthy vegetation on the right reflects only 40% of the near infrared spectrum and reflects over three times the amount of visible light as the healthy vegetation. |
A few pieces of equipment will be necessary for this assessment. The Tetracam Lightweight Agricultural Digital Camera (ADC-Lite) provides imaging in the 450-1050 wavelengths, perfect for capturing visible and near infrared imagery, and retails at $3795 (Figure 6). This can be used to create a NDVI image, using a program such as Erdas Imagine.
 |
| Figure 6. This shows the Lightweight Agricultural Digital Camera (ADC-Lite) (Tetracam.com). This camera acquires imagery in the wavelengths between 450-1050 nm (Colomina and Molina, 2014). |
A higher end visible light spectrum camera, such as the Sony Nex-7 would be able to show vegetation colors and potentially help to show when the pineapples are ripe and have changed colors. This unit retails for $1099 and a multitude of lenses can be purchased to enhance the zoom capabilities of the camera (Figure 7).
 |
| Figure 7. The Sony Nex 7 is a favorite visible light spectrum camera for UAS purposes (Colomina and Molina, 2014). |
Conclusion
The use of unmanned aerial systems is a growing industry. Commercial and recreational uses continue to expand as low altitude airspace continues to fill up with more and more users. This ability of a company or business to utilize UAS to assess issues that may arise offers an interesting alternative to issues previously solved using conventional aerial methods or by pricey ground reconnaissance. As the industry continues to grow, UAS will continue to grow in demand and everything from precision agriculture, to monitoring protected herds of animals, to monitoring chemicals in the atmosphere will provide us with a never ending well of data to analyze. Being informed and understanding the equipment necessary to complete a mission are essential concepts to making the use of a UAS a cost-saving venture.
References Cited
Colomina, I., & Molina, P. (2014). Unmanned aerial systems for photogrammetry and remote sensing: A review. ISPRS Journal of Photogrammetry and Remote Sensing, 92, 79-97. Retrieved March 1, 2015, from http://www.sciencedirect.com/science/article/pii/S0924271614000501
Draganfly.com. (n.d.). Sony QX100 Camera System with Single Axis Stabilized Camera Mount. Retrieved March 1, 2015, from http://www.draganfly.com/sku/DF-QX100I-1B.php5#Zoom
Falconunmanned.com. (n.d.). Retrieved March 2, 2015, from http://www.falconunmanned.com/
Handwerk, B. (2013, December 2). 5 Surprising Drone Uses (Besides Amazon Delivery). Retrieved March 1, 2015, from http://news.nationalgeographic.com/news/2013/12/131202-drone-uav-uas-amazon-octocopter-bezos-science-aircraft-unmanned-robot/
Krock, L. (2002). Spies that fly. Retrieved March 1, 2015, from http://www.pbs.org/wgbh/nova/spiesfly/uavs.html
Military Factory. (2015, January 4). UAV and Drone Aircraft. Retrieved March 1, 2015, from http://www.militaryfactory.com/aircraft/unmanned-aerial-vehicle-uav.asp
NASA EO. (n.d.). Measuring Vegetation (NDVI & EVI). Retrieved March 1, 2015, from http://earthobservatory.nasa.gov/Features/MeasuringVegetation/measuring_vegetation_2.php
Tetracam.com. (n.d.). Tetracam Products. Retrieved March 1, 2015, from http://www.tetracam.com/Products1.htm
UAV Insider. (2013, September 8). Rotary Wing vs Fixed Wing UAVs. Retrieved March 1, 2015, from http://www.uavinsider.com/rotary-wing-vs-fixed-wing-uavs/
Vividlight.com (n.d.). Spectrum of Light. Retrieved March 1, 2015, from http://www.vividlight.com/29/images/Spectrum%20of%20Light.jpg
No comments:
Post a Comment