Drone-Spectrometer With Great Applications In Life

Unmanned Aerial Vehicles (UAVs), commonly known as drones, have become indispensable tools for research and analysis across various industries. One of the most powerful and transformative technologies being implemented on these flying platforms is the drone spectrometer, which is essentially a spectrometer mounted on a UAV. This technology enables the analysis of light intensity at each wavelength, providing valuable insights into the composition, structure, and other characteristics of the objects or materials being examined. The implementation of UAV spectrometers has facilitated advanced research and analysis in numerous industries, leading to improved efficiency, reduced expenses, and the creation of new revenue streams. This article explores the industries that benefit from drone spectrometers and the range of tasks they can perform. It presents real-world examples of their impact on cost reduction and revenue generation.

METHODOLOGY

The process of data collection involves the use of a drone equipped with a spectrometer and a camera to fly over the target area and gather reflected or emitted light from the objects or materials under study. This data is then used to create a comprehensive database of spectra and RGB images. Subsequently, the collected data undergoes thorough processing and interpretation. It has been observed in numerous studies that the combination of sensitive spectral variables with robust and efficient algorithms leads to the generation of accurate models. There are many different processing algorithms, and the choice of the appropriate algorithm depends on the type of application. Commonly used algorithms include linear regression (LR), image differencing, matching pixel-by-pixel (mpp), artificial neural networks (ANN), and the Manning–Strickler and adaptive cosine estimator has been highlighted for their efficacy in interpreting spectral data.

Following a detailed method as in the reference that studies the method of using drone-spectrometer measurement and machine learning method to investigate land classification by using thermal sensing devices.

The spectral exposure is determined by applying the detector counts to the conversion function derived from the spectrometer calibration. The resulting spectral exposure values are then plotted against wavelength to illustrate the land cover signature at the specific footprint location, as depicted in Figure 1. The labeling of the plot is based on prior knowledge and visual assessment of the corresponding RGB image. 

Figure 1. Spectral Exposures of various land cover elements.

Spatial interpolation was conducted to address the discontinuity in terrain coverage observed in the spectrometer data. The inverse distance weighted technique was employed to interpolate from the irregularly distributed labeled spectrometer points. This process resulted in the generation of a continuous land cover classification map with a resolution of 20 cm, depicted in Figure 2a.

The classification process involved two distinct stages, beginning with imagery segmentation followed by object classification. Utilizing specialized software, the RGB orthomosaic underwent imagery segmentation to produce a classification map, which is depicted in Figure 2b.

Figure 2. Land Cover Classification and Assessment. a) Classification map produced by interpolation of labeled spectrometer points. b) Classification map produced by object-based image segmentation.

A spatial overlay operation was performed on the two classification map layers to identify the common land cover regions between them. Figure 3 illustrates how the land cover classes from the spectrometer classification intersect with various classes from the object-based classification.

Figure 3. Intersecting land cover classes.

APPLICATIONS

UAV spectrometers have revolutionized various industries with their ability to provide precise and valuable data. In agriculture, these spectrometers offer insights into crop health, soil composition, and moisture levels, empowering farmers to make informed decisions about irrigation, fertilization, and pest control. This ultimately leads to increased crop yield and revenue. Furthermore, in environmental monitoring, drone-mounted spectrometers enable swift assessment of air and water quality, as well as the monitoring of endangered species and habitats. In the energy sector, UAV spectrometers play a crucial role in inspecting renewable energy infrastructure such as solar panels and wind turbines, identifying issues, and enhancing overall efficiency. Additionally, in the oil and gas industry, these spectrometers are utilized to detect gas leaks, monitor pipeline integrity, and optimize extraction processes by assessing geological features. Lastly, in the field of archaeology, UAV-mounted spectrometers facilitate non-invasive analysis of artifact composition and the discovery of hidden structures, contributing to a deeper understanding of ancient civilizations.

SYSTEM  DESCRIPTION

The camera and spectrometer are mounted in parallel and perpendicular to the investigated plane, as depicted in Figure 4. A collimating lens is positioned at the entrance slit to capture the incident light. It is essential that the field of view (FoV) of the camera adequately covers that of the spectrometer to ensure comprehensive data capture and analysis.

Figure 4. Drone-spectrometer setup with a camera and a spectrometer are mounted by a drone.

The spectrometer plays a crucial role in this system, serving as the cornerstone of its functionality. The range of machines utilized in this system offers varying wavelength capabilities to accommodate different applications, allowing customers to select the most suitable device for their specific needs. Commonly used product lines such as ST, Ocean SR, Ocean FX, and FLAME are offered by Intins, each of which is compact and non-bulky, making them ideal for drone-spectrometer applications. These product lines, provided by Ocean Optics, are designed to be highly convenient and efficient for a wide range of spectroscopy applications.

The ST product line offers ultra-compact size, measuring 42.1 x 40.3 x 26.6 mm, making it suitable for various applications. It covers three wavelength ranges: ST-UV (180 – 650 nm), ST-VIS (350 – 810 nm), and ST-NIR (646 – 1085 nm), catering to diverse spectral measurement needs. With a short integration time of 3.8 ms – 6 s, the product is highly sensitive and ideal for use with moving drones, ensuring accurate and efficient data collection.

Ocean Optics also offers the 74-DA collimating lens, designed to provide optimal lighting collection. These lenses are versatile, with options optimized for the UV-VIS range (185-2500 nm) or the VIS-NIR range (350-2500 nm). They come in multiple versions including single, achromatic, and long focal length options. Additionally, the lenses are adjustable, allowing users to position them for converging to diverging field of view (~25°). The lens material is f/2 BaF10 and FD10 fused silica, ensuring high performance and durability.

Additionally, Intins is dedicated to providing customers with convenient and user-friendly drone-spectrometer control software. Our goal is to ensure that our software meets the specific requirements and applications of each customer, by offering the most convenient features for easy control and usage. We are committed to delivering a professional and seamless user experience, enabling our customers to effectively manage and utilize their drone-spectrometer systems with ease.

CONCLUSION

UAV spectrometers offer significant advantages by facilitating advanced research and analysis across a wide range of industries. Their capability to provide real-time and precise data on various parameters has proven to be immensely valuable in fields such as agriculture, environmental monitoring, energy, oil and gas, and archaeology. As technology continues to progress, the role of UAV spectrometers in revolutionizing research and analysis across industries is expected to become increasingly vital. With exceptional features readily available from Ocean Optics, customers can easily find a system that meets their requirements, making it one of the top choices in the market.