Drones

The radar technology will signal the following on the remote controller display;

• Signal that enough drone GNSS satellites have been detected and the drone is ready to fly
• Display the current position and location  of the drone in relation to the pilot
• Record the home point for ‘Return To Home’ safety feature

Most of the latest UAVs have 3 types of Return to Home drone technology as follows;

• Pilot initiated return to home by pressing button on Remote Controller or in an app
• A low battery level, where the UAV will fly automatically back to the home point
• Loss of contact between the UAV and Remote Controller, with the UAV flying back automatically to its home point

The latest Mavic Air 2 technology can sense obstacles during automatic return to home.

The propulsion system (motors, electronic speed controllers and propellers) are the drone technology, which move the UAV into the air and to fly in any direction or hover.  On a quadcopter, the motors and propellers work in pairs with 2 motors / propellers rotating clockwise (CW Propellers) and 2 motors rotating Counter Clockwise (CCW Propellers).

They receive data from the flight controller and the electronic speed controllers (ESC) on the drone motor direction to either fly or hover.

Top UAV drone motors and propulsion systems are highly advanced and include the following components;

• Motor Stator
• Motor Bell (rotor)
• Windings
• Bearings
• Cooling System
• Electronic Speed Controllers
• ESC Updater
• Propellers
• Wiring
• Arm

The Electronic Speed Controllers signal to the drone motors information on speed, braking and also provide monitoring and fault tolerance on the drone motors.

Nearly all drones have a Ground Station Controller (GSC) or a smartphone app, allowing you to fly the drone and to keep track of the current flight telemetry. Telemetry data showing on the remote controller  many include UAV range, height, speed, GNSS strength, remaining battery power and warnings.

Many UAV drone ground controllers use FPV (First Person View), which transmit the video from the drone to the controller or mobile device.

In order to increase flight safety and prevent accidents in restricted areas, the latest drones from DJI and other manufacturers include a “No Fly Zone” feature.

The no fly zones are regulated and categorized by the Federal Aviation Authority (FAA).  Manufacturers can change the no fly zone drone technology using UAV firmware updates.

When the compass is calibrated, it then seeks the location of GPS satellites. When more than 6 are found, it allows the drone to fly in “Ready To Fly” Mode.

Allows the UAV drone and remote control system to know exactly its flight location. A home point can be set and this is the location the drone will return to, if the drone and the remote control system stop connecting. This is also known as “fail-safe function”.

FPV means “First Person View”. A video camera is mounted on the unmanned aerial vehicle and this camera broadcasts the live video to the pilot on the ground.  The ground pilot is flying the aircraft as if they were on-board the aircraft instead of looking at the aircraft from the pilot’s actual ground position.

FPV allows the unmanned aircraft to fly much higher and further than you can from looking at the aircraft from the ground.  First Person View allows for more precise flying especially around obstacles.

FPV allows unmanned aerial vehicles to fly very easily indoors, or through forests and around buildings.

The exceptionally fast growth and development of the drone racing league would not be possible without FPV live video transmission technology.

This FPV technology uses radio signal to transmit and receive the live video.

The drone has a multi-band wireless FPV transmitter built in along with an antenna.  Depending on the drone, the receiver of the live video signals can be either the remote control unit, a computer, tablet or smartphone device.

This live video feed is related to the strength of the signal between the ground control on the drone.

The DJI Mavic 2 has an FPV live video range of 5 miles (8 km) with a 1080p quality video transmission.

Other, slightly older UAV drones such as the DJI Mavic and Phantom 4 Pro, can transmit live video up to 4.3 miles (7 km).  The Phantom 4 Pro and Inspire 2 use the latest DJI Lightbridge 2 transmission system.

Drones such as the DJI Mavic use integrated controllers and intelligent algorithms to set a new standard for wireless high definition image transmission by lowering latency and increasing maximum range and reliability.

Live video and maximizing the range of the transmission is fascinating drone technology. Here is a tremendous article entitled “Understanding FPV Live Video Transmission“.

In 2016, a new live video, which transmits over the 4G / LTE network, providing an unlimited range and low latency video was announced. This drone technology was released on the Sky Drone FPV 2 and comprises of a camera module, a data module and a 4G / LTE modem.

The flight control system communicates with a PC Assistant through a micro-USB cable. This allows configuration of the UAV and to upgrade the drone firmware.

A very simple description of a UAV drone is that it is a flying computer with a camera or sensor attached. Like computers, drones have firmware software, which send commands to the physical components in the aircraft or remote controller.

Drone manufacturers release firmware upgrades to fix bugs and add new features to the aircraft, remote control unit or software if it is used to fly the drone.

These are found at the front and the rear of the drone. Generally, drone LEDs will be green, yellow or red.

The front LED indicators light up to indicate the nose of the UAV.

The rear LEDs flight indicators light up to indicate the various status of the drone when power on, getting a firmware upgrade and flying.

It is a good to understand what the flashing LEDs on your quadcopter indicate.

All drones come with a user manual, which list what each type of flashing LED mean.

On the DJI Phantom(s), this is the wireless communication device using the 5.8 GHz frequency band. Remote controls systems are also known as ground control. The drone and the ground control should already be paired when it leaves the factory.

The location of the 5.8 GHz receiver technology link button is under the UAV. Almost, all the latest drones can use 2.4 or 5.8 GHz operating frequencies.

This is a wireless communication device which generally operate within the 2.4 GHz frequency. It is used to extend the range of communication between the smartphone or tablet and the drone in an open unobstructed area.
Transmission distance can reach up to 2300 Feet. Each range extender has a unique MAC address and network name (SSID).

The latest DJI drones out of the box can fly with a range of up to 5 miles (8 km).
Older drones from the other top manufacturers can’t fly as far as DJI drones.  However, products such as range extenders are very popular, which can push the distance even further.

Most of the UAV drones today can be flown by a remote controller or from a smartphone app, which can be downloaded from Google Play or the Apple Store. The app allows for full control of the drone.

Each manufacturer will have their own app such as the Go 4 app from DJI.

The latest drones from DJI, Walkera, Yuneec and other manufacturers now include cameras, which can shoot film in 4k video and can take 12 megapixel stills.
The earlier drones used cameras, which were not fully suitable for aerial filming.  These aerial shots had barrel distortion because of the wide angle lens.

However, the latest 4k video drones such as DJI Mavic series, DJI Inspire 1, Phantom 3 Professional and Phantom 4 have a camera which is specifically designed for aerial filming and photography.

The best drone for professional aerial filming is the DJI Inspire 2 mounted with the DJI Zenmuse X7 camera.  The Inspire 2 image processing system CineCore 2.1, records video at up to 6k in CinemaDNG/RAW and 5.2k in Apple ProRes when used with the Zenmuse X7 camera.

The Inspire 2 is used by Hollywood producers. In fact, the Inspire 2 filmed all aerial and ground shots in a short film called The Circle with cinematic quality.

In the past few years, a number of integrated gimbals with optical and digital zoom came to the market.

DJI released the Zenmuse Z3, which is an integrated aerial zoom camera and is optimized for still photography.  The Zenmuse Z3, which had a 7 x zoom made up of 3.5 x optical and 2x digital lossless zoom creating a 22 to 77 mm equivalent focal length range, making it ideal for industrial applications.

DJI later released the Zenmuse Z30 camera. This powerful Zenmuse Z30 is an integrated aerial zoom camera has a 30 x optical and 6 x digital zoom for a total magnification up to 180 x.

This allows for more industrial uses such as inspecting cell towers or wind turbines to get a very detailed look at structures, wires, modules and components to detect damage. The Zenmuse is compatible with DJI Matrice range of drones.

The Walkera Voyager 4 comes with an incredible 18 x zoom camera.  The 18 times optical zoom camera on the Voyager 4 has unobstructed 360 degree filming.  It can film in 4k at 30 frames per second. The  high definition image transmission system uses a 3-axis brushless stabilization gimbal technology.

Walkera have also released their latest Voyager 5. This has an incredible 30x optical zoom camera.

The Voyager 5 includes redundancy systems such as dual GPS, dual gyroscope and 3 battery systems. It also has optional thermal infrared and low light night vision camera.

Gimbal technology is vital to capture quality aerial photos, film or 3D imagery.

The gimbal allows the camera to tilt while in flight, creating unique angles.  More importantly, the gimbal reduces camera vibration. These are mostly 3 axis stabilized gimbals with 2 working modes. Non-FPV mode and FPV mode.

Practically all the latest drones have integrated gimbals and cameras.  The leader in aerial gimbal technology is DJI with their Zenmuse range.

Lidar, Multispectral and Photogrammetry sensors are being used to build 3D models of buildings and landscapes.  Low light night vision and Thermal vision sensors are being used on drones to  scan buildings and landscapes to assist in agriculture, firefighting, search and rescue.

Drones can carry different sensors with the software combining the data together for better results.  This technology is known as sensor fusion and works as follows;

Sensor fusion is software, which intelligently combines data from several different sensors such as a thermal camera and a regular RGB camera sensor for the purpose of improving application or system performance. Combining data from multiple sensors corrects the errors from individual sensors to calculate accurate position and orientation information.

For example, multispectral sensors on drones can create Digital Elevation Maps (DEMS) of land areas to provide precision data on the health of crops, flowers, fauna, shrubs and trees.

For lidar and photogrammetry mapping, the UAV is programmed to fly over an area autonomously, using waypoint navigation. The camera on the drone will take photographs at 0.5 or 1 second intervals. These photos are then stitched together using specialized photogrammetry software to create the 3D images.

DroneDeploy is one of the leaders in the creation of 3D mapping software.  Their mobile app and Live Map is being used in various sectors for creating 3D maps and models. They have a specialized solution for the agriculture sector and their software will work with most of the latest drones.

Capturing high resolution images on a stabilized drone is very important. Using top photogrammetry software to process the images into real maps and models is just as important.  Some of the top drone mapping software is as follows;

• DroneDeploy 3D Mapping Solutions
• Pix4D Mapper Photogrammetry Software
• AutoDesk ReCap Photogrammetry Software
• Maps Made Easy – Orthophoto and 3D Models
• 3DF Zephyr Photogrammetry Software
• Agisoft PhotoScan Photogrammetry Software
• PrecisionHawk Precision Mapper / Viewer
• Open Drone Map
• ESRI Drone2Map For ArcGIS

You can read a review on the above drone mapping software in this article on best photogrammetry software for 3D maps.

In 2016, drones using Time-of-Flight (ToF) sensors came on the market.  ToF sensors, also known as “Flash Lidar” can be used on their own or with RGB and regular lidar sensors to provide various solutions across the sectors.

ToF depth ranging camera sensors can be used for object scanning, indoor navigation, obstacle avoidance, gesture recognition, tracking objects, measure volumes, reactive altimeters, 3D photography, augmented reality games and much more.

Flash lidar Time-of-Flight cameras have a huge advantage over other technologies, as it is able to measure distances to objects within a complete scene in a single shot.

Helps to keep the stabilizer and camera connected to the unmanned aircraft.

Having an excellent quality video software is essential for post processing. Most of the latest drones can film in Adobe DNG raw, which mean that all the original image information is retained for later processing.

Most unmanned aircraft use Linux and a few MS Windows.  The Linux Foundation have a project launched in 2014 called the Dronecode project.

The Dronecode Project is an open source, collaborative project which brings together existing and future open source unmanned aerial vehicle projects under a nonprofit structure governed by The Linux Foundation. The result is a common, shared open source platform for Unmanned Aerial Vehicles (UAV).

UAV drones in many ways are like flying computers.  With an operating system, flight controllers and main boards with programmable code, they can also be hacked into.  Drones have been developed to fly around seeking other drones and hacking into the drones wireless network, disconnecting the owner and take over that drone.  However, there is some practical ways to protect your drone from hackers.

All these latest drones have intelligent flight controllers and modes such as Follow Me, Active Tracking, Waypoints, Return To Home and others.  The Phantom 4 Pro from DJI has the most autonomous intelligent flight modes of any drone.  The Phantom 4 Pro has the following intelligent flight modes;

• Active Track (Profile, Spotlight, Circle)
• Draw Waypoints
• TapFly
• Terrain Follow Mode
• Tripod Mode
• Gesture Mode
• S-Mode (Sport)
• P-Mode (Position)
• A-Mode (Attitude)
• Beginner Mode
• Course Lock
• Home Lock
• Obstacle Avoidance

One of the most exciting drone technologies is the ability to track subjects (people, vehicles, boats), particularly in the area of outdoor sports such as running, cycling, skiing etc.  The latest drones with excellent tracking abilities is the Mavic 2 and also the latest Skydio 2 where it’s tracking is so good that it never loses contact with the subject it is tracking.

These drones uses their vision systems, detection sensors, GNSS systems, flight controllers, central processing and specific software to be able to track their subject with 100 accuracy.

There are many different technologies used to track drones and you can read further on the best follow you drones here along with their tracking systems.

Drones have so many terrific uses.  When you mount a camera or sensor such as LiDAR, Thermal, ToF or Multispectral, then the range of uses for drones keeps expanding.  Here is an excellent list of drone uses

• Aerial photography for journalism and film
• Express shipping and delivery
• Gathering information or supplying essentials for disaster management
• Thermal sensor drones for search and rescue operations
• Geographic mapping of inaccessible terrain and locations
• Building safety inspections
• Precision crop monitoring
• Unmanned cargo transport
• Law enforcement and border control surveillance
• Storm tracking and forecasting hurricanes and tornadoes

Over the coming years, drones will transform our cities, revolutionizing how people travel, how goods are delivered and how buildings look and are constructed..