Telecommunication

What is VLOS (Visual line of sight)

Admin

— 2 min read

VLOS: Maintaining a Clear View for Drone Operations

VLOS, standing for Visual Line of Sight, is a critical concept in the realm of Unmanned Aerial Vehicles (UAVs), commonly known as drones. It refers to the requirement that the pilot or a designated visual observer must maintain continuous, unaided visual contact with the drone during flight.

Importance of VLOS:

  • Safety: Maintaining VLOS allows the pilot to directly observe the drone's position, movement, and surroundings. This enables them to react swiftly and safely in case of emergencies, obstacles, or unexpected situations.
  • Situational Awareness: VLOS fosters better situational awareness for the pilot, allowing them to make informed decisions about flight path adjustments, obstacle avoidance, and safe landing procedures.
  • Regulatory Requirement: In many countries, regulations mandate VLOS operation for certain drone categories or airspace restrictions. Violating VLOS requirements can lead to fines or even grounding of the drone.

Factors Affecting VLOS Range:

  • Drone Size: Larger drones with more prominent silhouettes are generally easier to see at greater distances compared to smaller, more compact drones.
  • Pilot's Visual Acuity: The pilot's eyesight plays a crucial role. Individuals with better visual acuity can typically maintain VLOS at greater distances.
  • Weather Conditions: Visibility significantly impacts VLOS range. Clear skies with good visibility allow for longer VLOS ranges, while fog, haze, or low clouds can significantly reduce the distance at which a drone can be reliably tracked visually.
  • Terrain: VLOS can be hampered by terrain features like hills, buildings, or dense vegetation that obstruct the pilot's line of sight to the drone.

Maintaining VLOS During Flight:

  • Pre-Flight Planning: Pilots should carefully plan their flight paths beforehand, considering potential obstacles and ensuring they can maintain VLOS throughout the planned flight route.
  • Visual Observer: In some cases, regulations might require a designated visual observer to assist the pilot, especially for complex operations or when the pilot's view might be obstructed.
  • Technology Assistance: While not a replacement for VLOS, some drone models offer features like First-Person View (FPV) systems that provide a real-time video feed from a camera mounted on the drone. However, FPV should never be solely relied upon for maintaining situational awareness and ensuring safety.

Limitations of VLOS:

  • Distance Constraints: The effective range of VLOS is limited by the pilot's eyesight and environmental factors. This can restrict the operational range of drones compared to other communication methods.
  • Human Error: Fatigue, distractions, or misjudgments can lead to pilots losing sight of the drone, potentially compromising safety.
  • Night Operations: Maintaining VLOS becomes extremely difficult or impossible during nighttime operations without proper lighting or night vision equipment.

The Future of VLOS:

While VLOS remains a cornerstone for safe drone operation in many scenarios, advancements in technology might lead to its evolution:

  • Beyond Visual Line of Sight (BVLOS): Regulations for Beyond Visual Line of Sight (BVLOS) operations are evolving, allowing for drone flights beyond the pilot's direct line of sight. However, these operations typically require additional safety measures like air traffic control authorization and robust communication systems.
  • Enhanced Situational Awareness Tools: Augmented reality (AR) technology integrated with pilot displays could potentially overlay real-time data and obstacle warnings on the pilot's view, improving situational awareness even with limited VLOS.
  • Autonomous Drone Operations: Advancements in drone autonomy might lead to scenarios where some flights can be conducted autonomously with human oversight, potentially reducing the reliance on VLOS for certain applications.

By understanding the technical details of VLOS, you gain valuable knowledge about a fundamental principle for safe and responsible drone operation. Maintaining VLOS ensures that drone pilots can effectively manage their flights, avoid hazards, and comply with regulations.

Read more