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INNOVATIONS.AVIATION.SPACE
HAB PLATFORM
Development of Unmmaned Aerial Vechile (UAV) Based High Altitude Balloon Platform for Active Aerosol Sampling
Development of Low-cost Near-infrared Agricultural Imaging (IR-ARGI) Subsystem Using High Altitude Balloon (HAB) Platform
Development of Unmmaned Aerial Vechile (UAV) Based High Altitude Balloon Platform for Active Aerosol Sampling
Knowledge on the abundance and diversity of the minute particles or aerosols in our stratosphere is still in its infancy, as aerosol sampling at high-altitude possess a lot of challenges. High-altitude aerosol sampling has been conducted mostly using manned flights, which requires enormous financial and logistical resources. There had been researches for the utilisation of high altitude balloon (HAB) for active and passive aerosol samplings in the stratosphere. However, the gathered samples in the payload were either brought down by controlling the balloon air pressure or were just dropped with a parachute to slow the descend speed in order to reduce impact when landing. In most cases, the drop location of the sample are unfavorable such as in the middle of the sea, dense foliage etc. Hence we designed and tested a system that actively samples aerosols at high-altitude and improve the delivery method in terms of quality and reliability using unmanned aerial vehicle (UAV). To the best of our knowledge, there is yet work on HAB-based aerosol sampling utilizing UAV platform for the safe return of samples.
Aerosol sampling is a method to collect aerosol particles at a specific area. Aerosol sampling is defined as capturing the contaminant from a known volume of air, then measuring the amount of contaminant captured and lastly expressing it as a concentration. Normally, aerosol sampling is done by capturing the contaminant using a filter paper which can have a different range of pore size. Subsequently, the volume of the air is measured against a number of air particles captured and this gives the concentration, which is expressed either as milligrams per cubic metre (mg/m3) or parts per million (ppm). Then, the volume of air is calculated by multiplying the flow rate through the filter medium by the time in minutes.
Figure 1 : SEM/DEX Analysis result
Figure 2 : Design of payload and sampling device
Development of Low-cost Near-infrared Agricultural Imaging (NIRAM) Subsystem Using High Altitude Balloon (HAB) Platform
Figure 1 : Near Infrared image of Paddy field, felcra seberang perak (Left), analyzed image (right)
Near-infrared imaging of agricultural sites can be applied for precision farming. This paper outline how a low-cost near-infrared agricultural imaging (NIRAM) can be applied as a subsystem of the Unmanned Aerial Vehicle (UAV) attached to the high altitude balloon (HAB) .The main mission of NIRAM on HAB was to demonstrate the feasibility of taking near-infrared videos (images) using a modified general-purpose lightweight mini camera. The subsystem has been demonstrated to provide near-infrared images of paddy fields to determine the crop conditions.
Our eyes can only see the reflected pigment of leaf, which is green. A healthy plant absorbs red and blue light produces energy via photosynthesis and produces more chlorophyll.
The more chlorophyll is produced, the more near-infrared energy is reflected. As the NIR radiations reflected by plants, are not visible through our naked eye, utilization of infrared (IR) filter will help to filter out the radiations.
In general the plant that produces more chlorophyll will reflect more NIR energy than the dying plant with less or no chlorophyll. The analysis of aerial images of crops that shows the range for both absorption and reflection of visible and IR wavelengths can give information about the plant’s healthiness and productivity.The relation of reflectance vs. wavelengths and the vegetation conditions and soil is shown in Figure 2.
Figure 2
Effect of Temperature at High Altitudes on Shape Memory Alloy (SMA) Response
Shape memory alloys are used in various fields, including aerospace. They have two distinct abilities, one being the ability to memorize a certain shape and return to that original state after being deformed. The other is that, they can produce strain through heating or electrical activation. They are widely applied as actuators in place of conventional ones, such as hydraulic, pneumatic, electric and mechanical due to the lightweight characteristics and small size. Shape memory alloys are part of a larger group of materials known as shape memory materials. Other common shape memory materials include shape memory ceramics and shape memory polymers. This paper will cover the study of the actuation response of a nickel-titanium shape memory alloy given surrounding conditions of varying temperature due to the change of altitude.
Shape memory alloys react to temperature changes by changing its dimension, specifically its length. Temperature changes can be achieved by normal heating or Joule heating. The size of the shape memory alloy allows them to replace larger, conventional actuators, to be used in smaller structures. Shape memory alloys has been proposed to be used in subsystem of aircrafts, including helicopters and airplanes. Blades of helicopters are retracted to save space while wings of airplanes are controlled to enable the morphing wing concept. According to a work by Darren Hartl and Dimitris C. Lagoudas, spacecraft such as small satellites use SMA wires too as release mechanisms, and also for energy or shock dissipation to counter vibrations.
