BVLOS and the use of long range LRFs in SAR

The cadence of commercial UAV innovation and applications is relentless, often creating challenges where regulations try to keep pace with technology.

UAV designers and operators want to exploit the full potential of their fleets’ sensor payloads, especially for emergency response missions like search and rescue (SAR). Yet regulators must be mindful of airspace traffic density and collision risk, which creates regulatory limits regarding flight range and altitude.

Visual line of sight (VLOS) is the first operational barrier for most UAV operators, but everyone, from industry to government agencies and regulators, recognizes the enormous potential of beyond visual line of sight (BVLOS) operations. Regulators are reshaping industry expectations by responding to advances in technology and operational realities, with the promise of evolving BVLOS approvals, which could dramatically enhance SAR mission reach and success rates.

The developing BVLOS and UAV space

The limitations of VLOS for SAR teams using UAVs are apparent. In Europe, VLOS and BLVOS altitudes are set at 150m (492ft), but with an airspace observer, BVLOS operators can range up to 2km (1.2mi) horizontally. In the US, that VLOS hard ceiling is 122m (400ft).

During the last two years, the US Federal Aviation Administration (FAA) has allowed more first responders and law enforcement agencies to operate UAVs in the BVLOS role. The FAA Reauthorization Act of 2024 is working to finalize Rule 108 this year, which could unlock new regulations and standards, advancing greater operational freedom in altitude and range for commercial UAVs in the BVLOS role.

The framework created by Rule 108 is expected to generate a demand surge for high-performance commercial grade sensors. BVLOS is unquestionably the next frontier for commercial drone operations, but what about the industry’s tier 1 sensor suppliers, who must service the market with appropriate product, as demand surges? Is the UAV and gimbal supply chain ready with sensors that feature the performance, ultra-light, energy efficiency, integration and cost to enable UAV and gimbal builders to meet the surge in BVLOS operational needs?

Better sensors for BVLOS SAR
When SAR teams succeed with near-range, low-altitude search patterns, operators gain more confidence and realize the potential of using UAVs at longer ranges and higher altitudes. This creates the need for sensors that are part of the EO/IR gimbal payload – sensors that can perform at greater ranges and altitudes without creating a size and weight issue, or increasing power consumption, and as a result reducing flight endurance.

The laser rangefinder (LRF) is crucial to any SAR mission. It makes sense of a search area by providing accurate depth perception and distance measurements. That data, in combination with the UAV’s GPS, can be developed into shareable, real-time location coordinates. When a missing person or object of interest in the search area is identified, localization coordinates can be shared, helping the SAR mission develop from a ‘search’ to ‘rescue’ phase.

Without a long range LRF as part of its sensor payload, UAVs operating in the SAR role might visually/optically locate a missing person, but fail to provide the accurate coordinates to aid the rescue ground team. Depth perception, distance measurement, sharply focused images and location information are invaluable to SAR teams. Understanding and interpreting the search area is impossible without real-time depth and distance data provided by a LRF to help confirm localization.

With BVLOS roaming freedom, SAR teams using UAVs can rapidly cover huge search areas, regardless of topography – deep into ravines or in adjacent valleys, way beyond the UAV operator’s line of sight. Flying at higher altitudes also gives the SAR UAV’s sensor payload a greater area scanning perspective.

BVLOS capabilities require LRFs with a broader spectrum of depth and distance measurement compared to traditional VLOS. Imagine the capability of a long range LRF with coverage from only a few feet above ground to altitudes and reach distance quadruple that of conventional 400-500ft VLOS regulated environments.

The challenge for SAR teams is sourcing UAVs and sensor payloads that feature long range high-performance LRFs with excellent operational efficiency configured for the BVLOS role and its extended ranges, at an acceptable cost.

SWaP-C always applies
For designers reimagining the specification of these EO/IR sensor payloads, there’s a need for long range LRFs that can deliver all the reach required in a BVLOS application, with excellent gimbal integration, lower possible power draw and weight.

BVLOS capability helps to solve the tyranny of range and urgency when operating across vast search areas. UAVs that fly higher, further and for longer can scan a more extensive search area. However, the issues prevalent in all UAV designs and SAR capability needs also apply to BVLOS operations: the technology and commercial UAV paradox of size, weight, power and cost (SWaP-C).

Efficiency margins matter for any SAR mission. LRFs that are too heavy decay flight endurance and hovering times. If they are oversized, there are packaging issues complicating gimbal sensor integration. Suppose the long range LRF you want is too expensive. In that case, you might only be able to afford a single SAR-effective UAV, instead of being able to convert the available budget to a fleet of high-performance long range LRF-equipped UAVs.

There’s no margin for error when operating BLVOS on an SAR mission. The control link between UAV and pilot cannot afford interruption when operating over vast or complex terrain beyond conventional signal networks. Excellent connectivity confidence and communications redundancy is not an expectation, it’s a necessity.

The multilink communication and signalling hardware enabling BVLOS add to the on-board power demands for SAR UAVs. That makes the overall sensor payload SWaP-C calculations crucial to conserve battery life and extend flight time, without depriving sensors of power and limiting their functionality.

Conserving power to enhance range
How valuable is saving battery power with a high-performance LRF drawing only 120mA, as part of your EO/IR gimbal sensor payload? The overall efficiency gain of having such a low-power draw as part of your sensor payload conserves battery power. Any on-board efficiency gain adds additional flight time, increasing the likelihood of a missing person’s discovery.

For first responder teams and law enforcement agencies, regulations are being reshaped to enable wider BVLOS allowances for the SAR mission. A more demanding mission scenario that requires long range LRFs with the best balance of SWaP-C principles to help build those BVLOS SAR fleets in numbers that first responder agencies need.

Evolving regulations are allowing more UAVs the operational freedom of BVLOS. For commercial UAV applications, like first responders operating in the SAR role, the developing need is matching sensor payloads with SWaP-C requirements. BVLOS operations are demanding, meaning the size, weight and power considerations matter for flight endurance, and cost is always an influence. Have you discovered the long-range gimbal integrated LRF that fulfils SWaP-C needs for your SAR teams operating UAVs in demanding BVLOS missions?