Enhancing Imaging Capabilities of Unmanned Systems with Precision Optical Materials

Unmanned and autonomous systems, ranging from drones and UAVs (unmanned aerial vehicles) to underwater and ground-based robots such as AUVs (autonomous underwater vehicles), and UGVs (unmanned ground vehicles), are increasingly dependent on sophisticated imaging systems. Whether it’s for surveillance, navigation, environmental monitoring, or industrial inspection, these systems rely on highly engineered optical components to deliver performance, reliability, and efficiency.

The Role of Optics in Autonomous Platforms

Imaging systems integrated into these unmanned platforms utilize a variety of sensors that cover the spectrum, from visible light to infrared. These imaging systems require high-precision optical components and assemblies that are designed to not only perform under challenging environmental conditions but also minimize SWaP (size, weight, and power), a critical consideration for airborne and mobile platforms.

Imaging systems commonly used in unmanned platform applications

Robotics and autonomous systems use visible light cameras for applications such as aerial photography, obstacle avoidance, and object tracking for navigation, and thermal imaging systems which often utilize SWIR (Short Wavelength Infrared), MWIR (Medium Wavelength Infrared), or LWIR (Long Wavelength Infrared) for applications like search and rescue, border surveillance, and pipeline inspections.

How optical components affect imaging systems performance

Precision optics can improve clarity, minimize distortion, and optimize transmission, which are crucial for data accuracy and real-time decision-making. This is vital to commercial applications such as industrial drone inspection and UAV mapping and survey, and also for military, law enforcement and public safety applications, for example drones used for monitoring and surveillance, situational awareness, and also CUAS systems.

What are the best lens configurations for UAV imaging applications?

Long focal length and continuous zoom lenses are often preferred for capturing high-resolution imagery at varying distances.

Optical lenses for drones and other unmanned platforms are crafted using a variety of substrates and geometries to suit specific applications. UAVs, for instance, often require long focal length lenses for capturing high-resolution images from significant altitudes. Continuous zoom lenses can provide flexibility across multiple scenarios while saving weight and space compared to interchangeable lenses.

Speaking about the selection of lenses for UAV gimbals, Dale DeJoy, Sales and Marketing Director at Meller Optics, explains;

“Sapphire windows offer critical protection for camera systems when in extreme conditions or fast flight. The windows can be coated to provide increased transmission, reduced absorption, salt fog and humidity resistance, and more.”

Considerations when selecting optical windows

Optical windows protect sensors and ensure optimal transmission for selected wavelength ranges, making them vital in harsh or dynamic environments. These flat, optically transparent elements protect sensors while maximizing light transmission within a specific wavelength range, be it UV, visible, or infrared.

Factors to consider when selecting optical materials include transmission range, refractive index, mechanical durability, and environmental resistance. Material selection is essential, as it must match the refractive index and environmental durability required by the application, such as high-speed drone flight or deep-sea exploration.

According to the experts at Meller Optics, sapphire provides transmission from UV through visible, near infrared and mid wave infrared. However it doesn’t transmit past 5000 nm well. “It provides strength and very good thermal qualities, with a melting temperature of 2400c” explains Dale DeJoy.

Optical domes and why they are used in robotic and marine systems

Domes offer environmental protection and wide-angle transmission, making them suitable for mobile, airborne, or underwater vision systems for example they are used on ROVs (remotely operated vehicles) to to protect cameras and sonar systems, enabling underwater exploration, inspection, and surveillance.

Protective and aerodynamic, optical domes are vital for housing imaging assemblies on mobile platforms. They maintain excellent transmission while offering mechanical strength and resistance to environmental wear. Materials such as UV fused silica, sapphire, and specialized polymers are often used, with advanced coatings applied to reduce reflection and enhance performance.

“Sapphire is the strongest and hardest optical material second only to diamond. A sapphire dome provides the strength required for extreme pressure experienced in deep dives and the dome shape allows a camera to have greater capability in regard to radius of view. The configuration is also the strongest available.”

– Dale DeJoy, Sales and Marketing Director at Meller Optics

The role of optical filters in precision unmanned applications

Optical filters isolate specific wavelengths for sensor calibration or environmental analysis. They play a critical role in allowing only desired wavelengths to reach the sensors while blocking all others. They are especially useful for applications such as industrial inspection and precision agriculture, where filtered spectral data can indicate plant health, hydration levels, and crop stress.

As unmanned and autonomous systems continue to advance, the demand for high-performance optical components grows in tandem. From surveillance drones to underwater ROVs, optics play a pivotal role in gathering critical data, ensuring mission success, and enhancing the capabilities of autonomous technologies.

Thanks to our expert contributors:

• Meller Optics – a leading manufacturer of high-precision custom optical windows, domes and lenses with 70+ years of sapphire optics fabrication.
• Knight Optical – a leading global supplier of metrology-tested, ultra-high-precision optical components for UAV, ROV, and robotics systems.

Featured image credit: Chess Dynamics, Boxfish Robotics, & Trillium Engineering