Drone-Based Downlinks: A Growing Part of Public Safety Operations

police drone

UAVs are rapidly becoming the platform of choice for situations where the use of conventional aircraft and crews may be cost-prohibitive or life-threatening. Their small and lightweight form factors allow them to be deployed quickly, providing a unique aerial overview for ground-based units to view, assess and control incidents. When configured with advanced downlink systems, like the Vislink AVDS, UAVs can play a critical role in public safety operations.

Public safety agencies have substantially increased their use of unmanned aircraft systems (UAVs, or drones) over the last few years. A recent study by the Atlas of Surveillance estimates that over 1,100 police departments nationwide are currently operating active drone programs, while many others are in the process of establishing UAS units. The interest is coming from both agencies without current airborne programs, as well as those with existing manned aviation programs that are starting to use drones to augment their capabilities.

Why are agencies interested in drones? Among the leading applications cited for utilizing UAV assets are to aid in tactical operations, criminal pursuit, search and rescue operations, crowd control and border patrol. Safety and cost are key drivers. Most LEO’s don’t necessarily need or cannot afford manned aviation programs, and UAVs can provide an alternative solution for many missions. This is especially true in cases where the deployment of conventional aircraft could potentially put crews in danger. Drones are generally small, lightweight, easy to operate and available at low cost. The ability to carry a camera capable of transmitting live video from the air to the ground allows a UAV to enhance situational awareness for personnel and improves the overall safety of all participants and bystanders on the ground during an incident. UAVs can also be fitted with night vision cameras and heat sensors, which provide imagery that enhances operational information.

Sending actionable video and data from a drone or aircraft to the ground, known as “downlinking,” is essential for a successful UAV program. Downlink technology has been around since the 1940s in one form or another. Early downlink systems carried in manned aircraft used analog technology, which required bulky, high- power transmitters and could only send data to a single, ground-based receive site.

The inability to receive video at multiple receive sites, along with other issues, resulted in limited adoption of downlinking by both civilian and public safety users. Because of advances in both UAV and downlinking technology, however, that has all changed for public safety agencies.

Today, drones are small enough to carry in a vehicle, which greatly enhances their usefulness. Most drone operations do not require a large support vehicle or mobile command post. A single operator and observer can respond to a scene and within 10 minutes be flying and receiving video. Information observed by the drone operator can be radioed to other support personnel who are either en route or already at the scene.

Key Applications

Search and rescue operations (SAR), particularly in remote locations, are one of the most widely used applications of UAS. The operator uses the drone’s cameras, either daylight or IR, to search within a defined area. Once the operator locates the missing person, the condition of the person and their coordinates can be radioed to ground teams for recovery.

The use of a drone in SAR situations is a relatively simple and cost-effective way to take advantage of video and downlinking capabilities. The drone acts as a force multiplier, which allows search teams to cover more ground with fewer personnel. The use of drones on SAR operations can also free up helicopters to transport teams in and out of the search area. Close coordination between the UAS operator and manned aircraft is crucial to ensuring flight safety.

Drones are also increasingly deployed for firefighting operations. Wildland firefighters are taking small UAS into the field with them and are using the drones do low-level flight reconnaissance of the spread and collect video and data on oxygen and toxin levels, flame spread and likely source of the fire.  In close coordination with manned aircraft operations, firefighters are to locate hotspots and provide real- time video showing how the fire is behaving around them.

Drones have also started to see use during active shooter situations, allowing law enforcement officials to better coordinate their entry strategies without exposing their personnel unnecessarily to risk.

Downlinking Up

The digital age has ushered in new technology, allowing airborne downlink systems to became smaller and more reliable. The systems can now downlink encrypted high or standard definition video to multiple receive sites. With additional equipment, IP (internet protocol) technology can also be used to distribute video over the internet to an unlimited number of viewers with the proper software and sign-on credentials.

Using drones to downlink video first came into use by the military during airborne intelligence, surveillance and reconnaissance missions. Battlefield commanders on the ground use the actionable information provided by UAS to make better-informed decisions or for tactical planning purposes.

The majority of drones used in public safety operations today offer many of the same benefits of their earlier iterations but are less expensive and complex. Several years ago, small and easy-to-fly quadrotor drones arrived on the civilian market. These drones, mostly manufactured by DJI, are relatively inexpensive, can capture still images and downlink video, and are the most widely used by public safety agencies today.

Information Relay: Key Elements

When deploying and operating UAVs, public safety agencies typically use a team comprised of a vehicle operator and observer. The operator is often the only one who sees video from the drone. Depending on the mission, the operator or observer typically radios information directly to an incident commander.

Regardless of the use case, key elements are essential to the acquisition, gathering and transmission of visual information from drones used in law enforcement to parties on the ground. The first is video quality. The difference between mission success and failure can be the result of poor picture quality when making critical operational decisions. Today’s most advanced airborne downlink systems employ coded orthogonal frequency division multiplexing (COFDM) modulation. Unlike other modulation schemes, COFDM maximizes its parameters for uncompromising reliability, delivering robust, non- line-of-sight video transmission over extended distances.

A second crucial element, which first gained traction in military drone usage and is becoming a must-have for law enforcement, is the ability to simultaneously broadcast video to multiple devices. Today’s leading professional-grade downlink systems allow multiple disconnected devices to view drone-captured transmissions by wirelessly sharing the video to incident commanders and other responders at mobile command assets on handheld devices and at receive sites across a wide area.

Having the ability to relay feeds from receivers using 5G and bonded cellular technologies further enables low-latency, broadcast-quality transmissions. Thanks to Vislink’s recent acquisition of Mobile Viewpoint — an innovator in mobile streaming solutions for news, sport, security and public safety agencies — we now offer complete security solutions for real-time, encrypted, low latency mobile video surveillance and temporary fixed setup using 5G and bonded cellular connections.

MVP drone downlink workflow 2

Using the Mobile Viewpoint streaming platform for drones, it is possible to connect a camera and live stream securely over multiple 5G/4G networks, Wi-Fi and fixed lines simultaneously back to a control room reliably and with the highest quality by using Mobile Viewpoint’s IP bonding transmitters. Video is downlinked to the drone ground base station using normal streaming functionality, then via an HDMI port to the ground base station, and finally in real-time to a control room.

Ensuring that real-time, uninterrupted video from all aerial assets is transmitted to decision makers, regardless of their geographic location, allows the full benefit of airborne systems to be realized. The growing number of use cases that are amenable to UAV deployments make it very likely that they will increasingly play a role in public safety operations.

Vislink’s Airborne Video Downlink System (AVDS) is an IP-centric, bidirectional, comprehensive solution comprised of downlink transmitters, receivers and antennas that capture real-time, seamless high-definition video from drones, helicopters and other aircraft. Vislink’s Air-to-AnywhereTM design allows collected video to be distributed, viewed and managed across wide areas to all deployed assets. The video can be forwarded over secure IP networks and streamed over cellular and WiFi networks for remote viewing on smartphones and tablets. Vislink AVDS can help ensure operational flexibility and enhanced tactical advantage for broadcasting/ENG, law enforcement, military and OGA customers.

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