The employment of drones and automatic image analysis offers new possibilities in traffic surveys, thanks to the accuracy of the measurement, the coverage range and the uniqueness of the obtained data. The camera is the most sensitive on the change of the position of ground objects in all directions when using the bird’s eye view. The dynamic occlusion between individual objects is minimalized as well.
These factual reasons together with advanced algorithms for extraction of traffic data ensure perfect information about every single participant of traffic flow.
- Angle of recording/ drone position
- Lens speed / parasitic optical phenomena
- Resolution & framerate & bitrate
Angle of recording / drone position
In terms of accuracy of vehicle localization, the most ideal drone position is directly above the intersection — so-called TOP DOWN VIEW. At this position, the camera is the most sensitive to the change of the position of the object in the scene, therefore an extremely precise measurement of vehicle speed and acceleration is made possible. At the same time, the dynamic occlusion between individual objects is minimalized. Nevertheless, drone suspension directly above the traffic node is not always possible due to safety regulation and applicable legislation. In a situation like this, a simple rule applies — place the drone in such position that the view of the analyzed section is near to the bird’s eye view.
The procedure is as follows:
- Fly with the drone to the nearest possible place in the middle of the intersection.
- Ascend to the maximum possible height. However, do not cross the height where a pixel resolution of monitored objects would be less than 20×20 pixels.
There is a notable drop of the accuracy of the vehicle localization (please note that this does NOT hold for DETECTION or for CLASSIFICATION) if the angle of the view is higher than 55 degree.
A simple rule is as follows:
- Angle of incidence ˂ 55 degrees = the drone should always be higher than the distance between the projection of the drone position on the ground and the center of the intersection.
- 45 degrees means, that the drone altitude is the same as its distance from the center of the intersection.
- 0 degrees means that the drone is directly above the intersection.
The drone should always be positioned in that way so the dynamic and static occlusions are avoided. Occlusions increase the probability of failure of object tracking and of disengagement of continuous trajectories, in other words, one object will have a higher number of shorter trajectories. The systems are robust against short occlusions, but long occlusions can cause the disengagement of continuous trajectories into more parts.
Try to keep the drone in the same position when recording. Do not change the drone altitude nor the camera take and zoom when recording. All parameters should have been set before the start of recording. For high-quality recordings, it is better to use a camera with ultra-wide range lens, not with fish eye lens, which causes high distortion especially noticeable at image margins.
Parasitic optical phenomena / lens speed and scene acuity
When recording, try to avoid parasitic optical phenomena in camera take, which may be caused for instance by the sun or another strong source of light. Always turn the camera in such a way that this strong source of light is not recorded by a camera. Takes of scenes with sky should be avoided.
Focusing should always be carried out in such a way so the vehicles / objects are not blurred in a take. At the same try to set the camera in such a way so the objects are contrasting but not over-bright nor too much dark. This should be considered even at the expense of other parts of the shot. In case of night recordings or the recordings at the low light conditions, it is important that besides vehicles also the traffic elements are visibly identifiable.
An image from camera ought not to be deformed by shaking (caused by drone motor vibrations) as a majority of cameras use the rolling shutter function to load image data in rows. If the vibrations are not sufficiently damped, their effect will occur in the form of shaking in between rows within the image. This shaking then lowers the accuracy of the used stabilization methods. Motor vibrations can be damped with suitable damping elements.
Resolution, FPS and bitrate
Resolution is a key attribute for the detection and classification of objects. The minimal size of an object within the image (for its detection) is 15×15 pixels, while for its correct classification, a resolution of 30×30 pixels is needed. A recommended size for objects within the image is between 30×30 pixels up to 150×150 pixels in the whole monitored area within the intersection. Object size depends on the following parameters:
- Image resolution
- Drone’s position — altitude / angle
- Mutual position of a monitored object and a drone/camera
A common rule is that if you record the video with maximal resolution used by modern cameras these days (e.g. 4K or 5K), it will be sufficient, as it is always possible to reduce the quality, but not the other way around. The following is a simple guide for resolutions:
- A distance with oblique angle < or = 120 meters -> FULL HD (1920×1200) resolution will be sufficient, but it is better to use a higher resolution (2k/4k)
- A distance with oblique angle > 120 to 300 meters -> use 4K video resolution
Framerate represents the sampling frequency of measurements. For vehicle speed up to 70 km/h, it is possible to use a framerate 15FPS. For vehicle speed over 50 km/h, it is better to use sampling frequency around 25 FPS. Sampling frequency over 35 FPS has no further positive effect on the quality of measurement, but only makes the video and its size unnecessarily large. The final quality of the video is also greatly influenced by bitrate settings. At FULL HD videos, coded with the H264 coding format, the bitrate should be at least 10 Mbit/s. At 4K videos, coded with H264, a minimum of 20 Mbit/s is necessary. The video must not be blurry, pixelated, or any signs of damage caused by compressing algorithms.
Tip for beginners: record video with 4K resolution and 25 FPS with standard bitrate (approx. 20 Mbit/s)
By following these rules you will get suitable videos for automatic processing to extract super-accurate data for your traffic study. Before the final recording, we recommend to carry out a test flight or make a few sample recordings in order to get acquainted with the basic principles. If you have any questions, do not hesitate to contact us.
Legislation & safety
Before the recording itself, always check what are the legal conditions for the recording of traffic in your country. Legislation differs from country to country and sometimes it is required to use services of a professional pilot with necessary permissions. There is also a predefined maximal flight altitude for drones in many countries (usually 120 meters), as well as a minimal safety distance (usually 50–120 meters away from objects). If the recording is carried out by a professional pilot, it is possible to gain permission even at different conditions. Always take the possible risks of technical failure into consideration.
If you do not want to carry out the recording by yourself, do not hesitate to contact us. We have a network of experienced and certified pilots all around the globe within the DataFromSky PILOT program. We will provide you with consultations about your project and its requirements in order to find the most suitable solution. We can also carry out the recording for you if necessary.
DataFromSky is a complex system for fully automated extraction of accurate traffic data using AI and machine learning methods. It has been developed and used for the purpose of traffic studies since 2013. DataFromSky AERIAL is a state-of-the-art and fully automated service for video analysis from the bird’s eye view (drones, balloons) for acquiring of super-accurate data not only for traffic research. DataFromSky LIGHT is a service for data analysis from low-altitude cameras for standard traffic research, fully automated as well. Try and see all the traffic magic FOR FREE!
We are happy to announce a release of a new version of DataFromSky Viewer and we have one breaking news for you: DFS Viewer LIGHT and DFS Viewer AERIAL were merged into ONE common software application DataFromSky Viewer. From now on, you do not have to install two different software, one for videos analyzed by LIGHT platform (light.datafromsky.com) and the other one analyzed by Aerial platform. The aggregated Viewer SW will display the features according to the log you open in it – what does it mean? If you have video processed by DFS Light and open the tlgx file in Viewer, the SW will show you the features for the LIGHT Viewer, and on the other hand, if you have a drone video analyzed by DFS Aerial and open the tlgx file in this aggregated Viewer, the SW will automatically enable you all the advanced features available for Aerial analysis. Be smart and use one application for all results!
New features of DataFromSky Viewer:
* one common version for both services AERIAL & LIGHT (automatic SW configuration according to opened file)
* GRID maps
* new type of filter “Traffic Region” – measuring time of staying, number of vehicles within the defined zone (region)
* supported new speed units: kilometers per hour [km/h], miles per hour [mi/h] or feet per second
* significantly speed up video playback even for 4k video
* new option to export the visualization video in .mp4
* new option to specify export resolution (“Original”, “2160p”, “1080p” and “720p”)
* option to lock project tlgx file (only in registrated, licensed version)
You don’t have an account on DataFromSky Web Platform yet? Go to light.datafromsky.com, create an Account for free and test the automatic video analysis on your own videos! You will receive some free Credits as a welcome gift. Download new version of DataFromSky Viewer directly at this link or go to the Task manager on your User Account. Tricks and tips on how to use the SW are “hidden” in our Help section.
How to deal with busy streets in the center of Berlin? Buses, trams, cars, cyclists, pedestrians can be seen everywhere moving without any rules. Is it possible to build car-free, bicycle-friendly & human-oriented city? Macromedia University of Applied Science in Berlin did concentrate on this issue as a part of Master Course Smart City Design and DataFromSky played a key role in the process of analysis of traffic and behavioral patterns and creating proposals for design changes!
How was the whole concept proceed?
Different groups of objects have been defined at the beginning of the analysis. Then a video of chosen intersection or street was taken and analyzed by DataFromSky software. Based on these data new concept of the intersection/street was designed.
Students have chosen different places around Berlin for the analysis. We have decided to choose 3 of them as a Use Case of our DataFromSky Light service.
Crossing Redesign Analysis and Concept
This analysis was done for an Intersection of Köpenicker Straße and Manteuffelstraße. Video from this intersection was analyzed by DataFromSky to get number of objects. Based on obtained data new concept of the people-oriented street was designed. New concept includes 2-Way Bike lane with limited speed, lines for cars & buses with slowing elements and giant crosswalk in the middle of the intersection with light signalization that helps to manage the flow of all participants.
Situation before and after, Author: Anja Lüttmann
Car-Free & Bicycle-Friendly & Human-oriented place
One of the analysis was focused on the heavy used intersection of Kurfürstendamm and Joachimsthaler Straße nearby Berlin city center. The aim of this analysis was to design car-free, bicycle-friendly & human-oriented place. Thanks to DataFromSky software most common vehicle, bicycle paths and pedestrians movements were identified and based on these data new concept of car-free place was designed. See the analysis output below:
Authors: Bensu Ece Tugyan — Tugan Can Tureli
Aim of this analysis was to analyze and design new car-free concept of Bergmanstrasse in Bergmannkiez. The objects (such as Cars, Bicycles and Motorcycles) were analyzed by DataFromSky software – counted, analyzed the trajectories, behavior patterns etc. Based on this analysis new concept of street lanes were defined. See a proposed design below:
Author: Alicia Baeck
Read the whole article from Berlin Macromedia School here.
Do you want to use DataFromSky and analyze the traffic in your city?
Thanks to DataFromSky Light you can get:
– Origin-destination matrix, turn-movements
– gate counting
– stationary time
– recognition of colors of objects
– object classification, up to 16 categories in total
– various export options (Excel, CSV, visualizations)
– …and much more!
Try it now on your own videos – register here.
In case it is not enough for you, try our DataFromSky Aerial service that can provide complete and detailed telemetry data about each traffic participant:
– complete object trajectories (time, position, speed, acceleration in coordinate system UTM or WGS84)
– classification of all objects into 7 main categories (including bicycles and pedestrians)
– vehicle counts via configurable counting gates
– detailed OD matrix and turning movements count in defined directions
– speed and acceleration anywhere in the scene, heatmaps
– lane assignment
– measurement of critical headway (gap) and follow-up headway, capacity estimation
– safety analysis (Time to collision measurement, PET, Heavy breaking), see a video
– many other advanced features!
Do you want to use DataFromSky software or do you have any questions? Do not hesitate to contact us!
Can something as common as a camera be transformed into a complex mobile monitoring system for advanced analysis of traffic? Can we distinguish anomalous and aggressive behavior of drivers, acquire full trajectories of vehicles or even detect traffic accidents before they happen? These are some of the questions that the newest edition of a smart city magazine called D!CITY tries to answer, which included also two smart city solutions using cameras: DataFromSky and ParkingDetection and also smart city platform of our partner OMS Lighting.
In the past, the main task for cameras was to record stories, which could be, unfortunately, interpreted only by humans. Nowadays, thanks to the increasing availability of high-quality cameras and mainly due to the immense technological advancement in the field of artificial intelligence and machine learning, the camera has become a universal sensor with application in many fields of the smart city concept, as they can serve as “the smart eyes of smart cities”. This marks the beginning of a new era, where image can be processed also by machines and where camera represents a rich source of data at even very low costs. What are the main areas of traffic analysis, where a camera already proves itself in action?
In times where individual transport increases faster than ever before, traffic congestions or even collapses can occur on a daily basis. Fortunately, there are systems which can help to achieve more fluent traffic even without expensive infrastructure changes, you just need a certain bird’s eye view. If we give camera “wings”, for example by attaching it to an unmanned aerial vehicle, we get a monitoring system for advanced traffic analysis which is not only very accurate but also at an affordable price. This is exactly what our project DataFromSky deals with – as there are several research projects that require just this type of traffic analysis. The system can detect vehicles and other participants of the traffic flow, which includes not only their trajectories and speed but also detection of possibly dangerous behavior with deep-learning and artificial intelligence. This can even detect traffic accidents before they actually happen, which can provide the traffic engineers with very valuable data about causes of traffic accidents within the tested area in order to look for ways how to avoid them in the future with convenient preventive measures.
Cameras are becoming a prominent technology for traffic analysis also at so-called “adaptive intersections”, as they can accurately detect not only vehicles, but also pedestrians and cyclists, which also play an important role in the given traffic flow. With smart traffic lights control, based on data from a network of sensors, the whole system becomes way more fluent and flexible when it comes to reaction to rapid changes within the traffic, making it also a lot safer. Another use of cameras lies in the field of smart lighting, as the camera can collect visual data and use to analyze public spaces, monitor traffic or detect anomalous behavior. This gives us many possibilities of designing smart streets with the use of a smart camera system, using something as common as public lighting.
Traffic congestion can be also caused by the situation in parking, especially in situations when drivers are trying to find an empty parking space in an infrastructure, which is already overloaded. One of the possible solutions is to use current parking spots more effectively or even navigate drivers to parking lots with available places to park their car. This is the main area of focus of the system called ParkingDetection. As far as technical and economic aspects are concerned, a camera represents a suitable sensorial solution for monitoring of even tens or hundreds of parking spots, as even very large parking lots can be covered by a single smart camera at very low costs, while magnetic sensors would be extremely expensive and even less accurate. If we also add an ALPR camera for number plate reading into the system, we get a significant number of potential technical solutions for residential parking, reservation of individual parking spots or even increased safety within the parking lot.
Are we on the brink of an age of cameras? In the not-so-distant past, autonomous vehicles, or using drones for traffic analysis would sound like science fiction. Nowadays, these technologies are already becoming a reality, also thanks to the advancement in cameras and artificial intelligence. It is becoming clear that cameras will play an important role in the future of smart cities.
The whole magazine can be found at this link.
The whole team of RCE systems would like to thank all visitors of our stand on URBIS: Smart City Fair 2019, held in 5. and 6. 6. 2019 in Brno Fair Trade Centre.
We believe that solutions sparked the interest in technologies and services for cities of tomorrow. We are glad that we had a chance to introduce our solutions DataFromSky and Parking Detection to the public.
We have presented our newly released platform DataFromSky LIGHT, introducing the fully automated service of traffic from various ground video sources such as traffic surveillance cameras, action cameras, camcorders or even smartphone, and also DataFromSky AERIAL = advanced technology for traffic analysis of aerial videos recorded by a drone or balloons. Our public presentation about drones, AI and traffic monitoring impressed the visitors as well.
Parking Detection was represented by a small interactive model, on which every visitor had a chance to find out how the system works and its key benefits = accuracy, cost-efficiency and openness for integration into other SmartCity platforms.
Thanks to our partner OMS Lightning we had a chance to show, how can ParkingDetection be integrated and contribute to a complex city IoT platform such as CitySys.
Have a look at few pics from the event below.