DATAhawk is a compact mapping UAV designed specifically for easy-of-use, rapid deployment, high resolution, photogrammetry missions. Fully autonomous with multiple landing options including para landing, the main sensor in the surveying edition takes the incredible 20.1mp Sony QX1 in a gimbaled mount. Including Pix4D Mapper, the system provides a turnkey solution. Endurance is great; expect up to 1hr of flight with coverage up to 20 square kilometres. The entire ultra-rugged drone is sub-2Kg, with a 115cm wingspan.
The agricultural edition - DATAhawk Ag - mirrors the surveyor in capability - replacing the main sensor with a MicaSense RedEdge multispectral unit. This advanced, lightweight camera is optimised for use in UAVs of our type and size and provides accurate multi-band data for agricultural remote sensing applications. Crop health, growth and feed patterns can all be monitored with the data retrieved.
QuestUAV's Flying Team Starts Large Team International Training
One of QuestUAV Ltd's flight training teams arrived in Indonesia this past weekend, to provide in-country training for GGP (Great Giant Pineapple). Sunday saw the completion of a successful series of test flights with Q-200 AGRI Twin NDVI aircraft.
Q-200 Surveyor Pro Flight Training (L) Stuart; QuestUAV Pilot with GGP Trainees (R).
Training began in earnest yesterday and today saw the first flights with the flight teams in-country. Some 18 people from these teams (and other GGP staff with a need to understand the technology) are taking part in QuestUAV international training within Indonesia this week.
GGP grow a majority of premium Pineapple crop, although they are also responsible for Banana, Palm Oil and Casava plantation areas and a growing segment of other
tropical fruits. The plantations are over 30,000 Ha in area.
UAV images and the UAV project are phase one of GGPs initiative to integrate precision agriculture firmly within their growing processes. Phase 1 of this initiative are the UAV flight, monitoring and image collection missions that this current training is enabling.
Phase 2 will see GGP purchase large GPS-driven farm machinery to make use of the GIS output provided by the teams in Phase 1.
QuestUAV Addressing Safety Standards in Urban Environments
Drone mapping is growing at a rapid rate in almost every country in the world. Unfortunately, incidents with drones are also growing at the same time. Just like any other aircraft, drones not only need to be flown in a safe manner but flight operations need to fully integrated within a countries civil and/or military regulatory aviation environment.
Authorities such as the British Civil Aviation Authority (CAA), the European Aviation Safety Authority (EASA) or the Federal Aviation Administration (FAA) of the United States provide rules and regulations for a safe and legal operation with the aim of minimising dangers to people, property and other aircraft.
In this case study we look at measures and counter measures that QuestUAV have employed to enhance safety when operating in urban environments through the example of our Korean flight team from Hojung Solutions. The team operates QuestUAV drones for a variety of urban applications while they are obliged to follow the strict rules of the South Korean aviation authority. Their advanced in-country training from QuestUAV has allowed new standards to be set for the use of drones for civil applications in South Korea.
Different kinds of UAVs have specific applications. While rotary drones are designed to inspect small areas in highest detail, fixed-wing drones can be operated over long distances and cover large areas in a short amount of time.
QuestUAV has long been a thought leader for safe drone operations and we support the highest standards of safety for fixed wing UAVs.
Applications and Safety in Urban Areas
Urban areas have various faces and UAVs can be used for a wide range of applications, starting from mapping urban zoning and expansion through 3D modelling of cities and cadastral surveys to inspecting infrastructure elements such as roads, pipelines and buildings. This study focuses on the experiences of the team from Hojung Solutions in South Korea, presented as an excellent example of the challenges of operating fixed wing UAV in built up and congested areas. Bearing in mind that South Korean safety requirements to UAVs are similar to the UK, QuestUAV drones are setting the standard for fixed wing drones in the country. Most importantly: the Hojung team is well-trained by QuestUAV as manufacturer and 100-percent professional in following safety standards and procedures at any mission.
South Korean team in action: pre-takeoff checks of a Q-100 DATAhawk (left) and pilot during flight (right).
Primarily the issue of maintaining Visual Line Of Sight (VLOS) whilst still retaining full control of the UAV were the highest concerns. However other issues such as higher rate of local interference, loss of visibility from high buildings, poor selection of emergency landing areas, higher risks of unexpected interferences (including unexpected public interactions and unexpected interactions as and when moving on highways) were of concern.
QuestUAV’s first level of consultation took us to examination of the aircraft, its safety functions and how it could fit governmental regulatory requirements. Parachute, manual and auto landings, motor failure and energy dissipation on impact, risk of unlawful interference and poor GPS signal, were all aspects that were considered and blended into the software and hardware setup for the UAV fleet to be used in South Korea.
The second level of consultation required verification of the QuestUAV system in South Korea and a detailed investigation into training sites that could be used where challenges were realistic but real risks were low. A site on the outskirts of a newly developed city was chosen that provided all the elements density and high structure to the East and North, whilst having open and safe spaces for operations to the South and West.
The on-site flight teams needed to be skilled in a larger range of disciplines. Third level of QuestUAV’s consultation was therefore the standard manufacturer training in South Korea. The lead pilot had also received further QuestUAV training in UK.
Ground Image of the Northern sector of the Survey Area (L) Crew brief and mission preparation (R).
The day to day process of briefing and equipment preparation needed to become an artform that raised standards in every area. One example is to use radio communication disciplines to allow remote observers to participate in an effective safety strategy that covered visibility in blind spots and better forecasting of events that might become risks.
Urban Mapping Examples
Our South Korean team from Hojung Solutions has been successfully flying in urban areas since autumn 2015. Their list of achievements is incredible. Some of the most impressive examples are already published on our website. The 300km road survey in South Korea was probably the team’s most difficult challenge.
In order to keep Visual Line Of Sight (VLOS) the flight team had to follow their Q-200 Surveyor drone on the ground in an open car and never be further away than 500m. The team took advantage of the QuestUAV safety features like dual system, ERP and orbiting options greatly supporting the mobile operations.
Other great achievements are the survey of Madang City in Papua New Guinea as basis to design a municipal storm drainage system and several high accuracy topographic surveys for the South Korean governmental survey agency. The figure below shows several examples of urban features and the general QuestUAV image quality.
QuestUAV image quality: Populated high-rise buildings, road intersection including road markings, river weir, village centre.
QuestUAV Safety Features In Deail
A well trained crew is of utmost importance for a safe flight mission. QuestUAV places high priority on training clients on a safe UAV operation, which involves more than just practicing takeoffs and landings. The whole workflow has to be practiced over and over again, starting from mission planning, base checks and crew briefing through to operating a UAV in different scenarios and a safe UAV recovery after landing. QuestUAV has long-term experience in operating UAVs in different conditions and for various applications. Proven workflows are one of our outstanding safety strengths.
An outstanding QuestUAV safety feature: the airdock stick launch.
QuestUAV drones involve great safety features, starting with the material characteristics of the UAV itself. Our drones are light but also very robust, meaning that they can absorb a high amount of energy during any impact. Depending on the system QuestUAV drones are launched via airdock (Q-100 DATAhawk) or launch line (Q-200 systems), which avoids direct contact between launch person and drone. QuestUAV drones are generally flown in automatic mode (including auto-takeoffs and auto-landings), but in case of an emergency the pilot can always take control and fly the UAV in assisted or manual mode. Our drones are dual-systems, meaning that either the pilot can take control with the remote control or the commander can operate the aircraft from the flight laptop. QuestUAV drones have an outstanding redundancy, including commercial avionics, fail-safe, geo-fencing, return-to-home options, battery warnings, ERP (Emergency Rally Point) and orbiting options.
UAVs must always be flown in a safe manner both with respect to other aircraft in the air and also to people and properties on the ground, especially when operating in urban areas. QuestUAV drones come with great safety features to reduce mission risk and provide high quality data at the same time. Professional manufacturer training on flight operation, safety and proven workflows is the outstanding safety feature of QuestUAV.
KAZ Minerals operate a large operation at Aktogay in eastern Kazakhstan, with an open-pit mine and on-site concentrator - Aktogay Open-Pit Mine
From this autumn KAZ Minerals surveyors have begun to use a Q-200 Surveyor Pro UAS (Unmanned Aerial System) in Kazakhstan. The UAS (also known as a "drone") greatly improves the efficiency of geodetic work, makes the results more accurate and increases the efficiency of developing the site.
The essence of the UAS at first glance is simple: traversing the sky above the survey site along with a neatly planned flight-path, the UAS takes numerous sensor images along with accurate location data for each image. Previously, surveying of this sort would require a lot of effort and resources on the ground - today this is many times faster.What's Involved
Sengeldy Bijanov, Senior Surveyor for KAZ Minerals at the Aktogay mine site
"Surveying services have remained in their current form for decades. Technology developments are continuously being placed in the hands of ordinary surveyors, we are no exception. Originally working one way, we have moved on to electronic tachometers and then with another step into GPS technology. And today begins our work with drones. Very quickly the UAS can obtain very detailed images. Usually, if a company needs aerial imagery a plane is employed, but this is very expensive and cannot always be used for this reason."
"Surveying in Aktogay today is mainly a photographic career. The work of the surveyor forms the basis for all further work in developing the mineral resources. Spatial geometric measurements are taken of the earth's surface, which are then used to develop and display the plans, maps and profiles required for mining and exploration"
How often do you collect imagery?
“Daily. To create the planning framework in which each location is shown on the plan, with further work performed by our engineers, planners and geologists. We also perform daily inspection surveys of the ore collected from the mining operations. To this end we have a team of experts trained, 8 at this stage - all fully trained to be able to fly and manage the UAS.”
Who performed the initial training?
“Fully qualified trainers from the UK, direct from the manufacturer of the Q-200 system. The first teams have been trained and now, if necessary we can receive further technical support remotely from the UK.”
Who spearheaded the initiative to buy a UAS for this service?
"The idea came from our chief surveyor, Gavin Cheshire. He is constantly looking for ways to introduce new technologies and new solutions, which can be used at different sites in a range of countries. A number of drone systems were evaluated and compared, before settling on the Q-200 Surveyor"
Drones are a fairly young technology, but they are already available widely - from military use to toy units for teenagers. The UAS you use was created specifically for industrial operations?
“Yes, this is a special Q-200 Surveyor UAS from QuestUAV. The company was founded in 2008 by the CEO, Nigel King - himself a former military pilot and Air Force instructor. They have developed different models, introducing models for civilian purposes - for example, agriculture and large area surveying.”
Reasonably expensive as a package with all sensors and sets of spare batteries
Training and Operations
Operation is probably different to a standard copter?
“Yes, training is not simple, it is very detailed and takes days. The UAS is not just a gadget with a remote - there is a laptop-based station with special control programmes installed on it. Flight trajectory and all flight data is displayed and so on. Another important moment is launch - everything needs to be timed, observed and adjusted for - wind speed, direction, hand position, etc.”
How have your colleagues found the training?
“The theory is supported by the practice. Already there is noticeable progress.”
And you learned how to operate it? I would think that at first, all hands would shake at the thought that you could cause these expensive devices to fall?
“Yes (laughs), but in that case repairs and spare parts can be ordered again, for delivery directly from the manufacturer in England.”
Briefly, tell us about the characteristics of the drone.
“Speed - about 1 km per minute. Maximum range - 55-60 km. One flight can last up to an hour. This is important for large areas and for areas that are difficult to organise flights around. For example, a panel of heap leaching (leach pit) - when they initially have their ore load laid you could get inside to start surveying, but today everything is acidic and direct ground access is severely limited.”
What will be the next technological leap, I wonder? What do you see next?
“I don't know, it will most certainly be possible to do everything without leaving the office. Prepare and pre-program everything, the aircraft itself will still fly and collect the data, process the results and here you are.”
Esengeldy Bijanov was interviewed by Almas Sadykov
Q-200 Launch Line System V2 - Safety and Efficiency Combined.
The Q-200 airframe, the workhorse of the QuestUAV fleet now flies with an upgraded launch line system. The system improves upon the original launch line in several ways, bringing more efficient and safer launches to flight crews for every mission.
Line Launched UAV
The Q-200 is a 2m wingspan UAV that launches via an extending bungee line.
-Dual Ground/Air launch trigger
Seamless transfer of launch power from line to prop.
-70% shorter line length
With a much-reduced line length, the launch area required is considerably smaller - opening up more options for launch site selection when flying missions.
-Raised Anchor Point
The new setup includes a static tripod guide which raises the line well above the final anchor point - keeping the launch profile well about Foreign object Debris (FoD) levels. The new higher end-point flattens the launch line angle which improves the UAV's launch trajectory.
-Double the power delivery
With the improved line materials, the power transferred to the UAV during launch is doubled, giving the UAV motor a head-start and saving launch battery power.
-Accurate Launch Trigger
-Static tripod guide
raises the launch above Foreign Object Debris (FoD) levels and optimises the launch trajectory.
-50% more efficient.
-Well specified for the entire fleet of sensor mounts.
The new launch system is capable of launching UAVs weighing up to 6kg - well in excess of QuestUAV's current line-up.
-Zero wind and cross wind capable
No power on until 2m from operator (safety)
Still packs down to 30x20
ZERO failed launches with the new line.
Passed the stringent safety standards for the world's mining community.
7 Tips for Successful Drone/UAV Operations in Cold Environments
Whatever the application around the world, be it mining, engineering, research or agriculture, in general terms small mapping UAVs are being increasingly utilized to observe the Earth’s surface in great detail - to monitor change over time. The analysis of this data enables better decision-making, resulting in increased efficiencies and cost savings to its adopters.
To do this efficiently and effectively in many locations, the technology and its users must be capable of operating all year round - effectively in either hot or cold environments. In this article we will look at some of the capabilities and disciplines required to operate in cold environments.
Cold sub-zero temperatures, wind-chill factor, snow and frozen solid ground are just some of the factors that make UAV operations in cold environments one of the most complicated tasks. Combining cold ops with a demanding flight schedule ? It does not get tougher than this.
To operate in cold environments, there a number of crucial operational factors to consider:
1. A well-trained and disciplined crew is worth their weight in gold:
Freezing temperatures and wind chill will significantly reduce the efficiency and performance of the team and equipment.
A well-trained, well-rehearsed and experienced team who understand the effects of low temperatures on both the crew and the equipment is key. Training, crew preparation, cold ops risk assessments, and equipment preparation for cold operations will best prepare the team and develop efficient workflows and procedures to mitigate risks to the mission.
Live mission simulations at the training site will pay dividends in understanding performance of UAV and crew in low temperatures - remember training is the best insurance policy as it focuses on learning new skills in a safe environment where there is the space and opportunity to safely make mistakes.
Live ops has limited scope for learning and focuses on data acquisition rather than UAV team building, cooperation and efficiency.
For crews, at zero degrees everything takes twice as long to complete, compared to +10°c operations. At -10°c everything takes at least four times as long. Crew roles and organisation becomes critical in the fight to prevent UAVs becoming cold-soaked during pre-flight preparations.
Remember – a well-trained team, combined with a well-planned mission will result in a safe and successful data collection.
2. Battery Performance
Small Mapping UAVs, on-board sensors, ground control laptops and transmitters are predominantly powered by Lithium polymer batteries (LiPo). It’s a fact, LiPO batteries are susceptible to performance issues when operating in cold environments. To combat this issue, many UAVs now use temperature sensors to warn the operators when a critical external temperature has been reached, triggering safety mode and disabling flight. Whilst this is a great safety feature, this presents a huge issue for businesses and research institutions that have time critical data requirements in cold environments.
At QuestUAV, we believe that the users must be able to dictate their own flight schedules in all environments. By implementing strict procedures and guidelines, the operators are able to get full performance from their UAVs in cold climates. Understanding the technology, the environment, utilizing a combination of on-board climate monitoring sensors and thorough pre-flight and in-flight checks, flying at sub-zero temperatures is an everyday reality.
Mobile ops vehicles need to prepared for safe transport of crew and equipment - all organized for efficient and rapid deployment. A 300w 12volt inverter is essential as power supply backup. Aircraft set-up/configuration correct for mission - Example: corridor mapping ‘point and click plan’ – use the gimbaled sensor Q-POD for the Q-200. This enables vertical mapping of the target whilst the UAV is in a bank - the UAV will bank on planned turns and in high or gusty winds. For Grid Plans – use the non-gimbaled sensor Q-POD, more robust and simple to use.
Keep UAV in Warm controlled environment (out of wind), vehicle or heated ops tent. Use spare LIPO and camera battery for pre-flights, insert fresh pre-warmed fully charged batteries prior to launch. Keeping batteries in coats or near heaters in vehicle can help to keep them warm. Ailerons hinges - Exercise ailerons pre start, ensure free moving and not ridged from severe cold. Remember at high altitudes the temperature will be colder – falling -1 degrees per 400ft)
Monitor flight time and battery voltage, if battery drains rapidly due to insufficient pre-warming, recover UAV and solve the issue. For example, replace freezing batteries with pre-warmed batteries and resume mission.
Out in the field, transport, mobile ops set-up, crews, efficient workflows, tools and spare equipment, documentation etc. are critical. Experience will continuously inform and advance operational capability, as long as crews adhere to their training.
Make sure all spotters are well briefed, including full safety card procedures, locations and telecoms etc.
Crew preparation - Trained, fully briefed on all stages of the mission, on-time and kitted out for cold ops.
Use all available resources including additional spotters if you can.
Re-evaluate risk assessments in cases of crew and spotter changes.
Desk Study, Risk Assessments, 48hr Checks and UAV Base-Checks must be fully understood and systematically completed and documented. All crew fully mission briefed, crew roles and hierarchy firmly established. Remember last minute crew changes carry high risks that require teams to either mitigate the risks or potentially cancel the operation.
Remember your operations documentation and video your missions for post flight analysis and crew training – it is very important!
4. Field-serviceable technology.
Spare and repair equipment is essential for all operations. Remember in cold operations the crews will have limited ability to repair on-site, however spare components are required to succeed. Landings are tougher on a cold UAV airframe, most materials become more brittle as temperatures fall - causing increased risk of damage through the fracturing of cold materials. Sustained exposure to the cold whilst handling equipment and fine electronics can lead to rapid crew inefficiency or incapacitation. In cold environments, field repair capability is limited. Normal tapes no longer adhere and glue repairs don't set. Airframe EPP foam will experience shrinkage, wing surface laminates will slightly wrinkle and increased prone to cracking. EPP becomes solid, doesn't compress and therefore transmit increased landing shock through the UAV. Gimbals become tighter in the EPP body.
Remote operations in cold environments require task specific spares. Pack cold ops spares.
A good sized vehicle is important for UAV pre-start warmth, crew protection, UAV ops, keeping batteries, laptop and transmitter warm, carry spares. Alternately use a 4m x 4m heated operations tent kept at 10°c (Electric or gas radiator heaters)
5. DATA – what it's all about!
After all the fixation on the array of aerial data collection vehicles available on the market, weeks spent scrutinizing specifications and deciding which one fits your needs, essentially UAVs are there to carry a sensor to capture accurate, quality data. So what about the all-important DATA and how can cold operations affect it?
Usually, there is less light available at all stages, resulting in small flight windows. Also, remember low light will have a negative effect on your image quality.
In addition, unbroken snow can prove problematic when processing your data - similar to difficulties with mapping water bodies.
For the operations team, everything must go right to be safe and successful - make sure they understand and follow all cold-weather procedures.
6. Flight Planning.
Assess target area and weather. Visit site if possible, carry out full desk study and 48hr checks. Calculate flight time, factor in potential loss of endurance due to flight plan altitude, temperature and weather.
Avoid planning a downwind position of UAV at end of flight, batteries will be low and fighting against wind will not help.
Equipment Preparation - Full base checks. Use a shadow board.
Remote operations in cold environments require task specific spares. Pack cold ops spares and UAV in one vehicle.
Send planning documents to QuestUAV or your technology partner for pre-ops analysis.
7. Technology Partner
Finding the right equipment for the job is crucial. Understanding the equipment and your roles in deploying it are equally important. Harsh environment proven systems and accompanying workflows are a basic requirement and a technology partner that will support you directly is often overlooked and plays a pivotal role in successful application of the technology.
Demonstration of High Geospatial Accuracy Achieved by a Fixed Wing UAV
1 (3cm) pixel accuracy across 2 Km grid using a QuestUAV Surveyor Pro UAV
1 Survey Objectives and Deliverable Items
The purpose of this survey was to achieve a high accuracy topographic map and Digital Elevation Model (DEM) of a study area in a foreign country that:
(a) was managed by an independent and competent third party, totally independent to QuestUAV. (b) provided the opportunity to compare QuestUAV performance against other UAV vendors such as EBEE, Dronematrix, Trimble, UAVER
The survey was conducted in August 2015 in South Korea, under the auspices of LX, the South Korea governmental survey agency.
The agency laid out a set of twelve Ground Control Points (GCP) spread across the 1200m x 1200m survey area.
To check consistency the agency also laid out six Control Points (CP’s) across the survey area with the intention that these be used to independently confirm the accuracy of the survey after it had been completed. The survey has returned excellent results with an average accuracy of 3cm (1 pixel) across the survey area, using the control points for validation.
In accordance with our agreement with the agency, QuestUAV has the following deliverables associated with this survey. (All deliverables are available through our Geotech department, identified at the end of this document.)
Survey report (this document), including a survey description, a summary of the results and a basic image analysis.
A3 map of the survey area (PDF format).
Image processing report (Agisoft Photoscan).
Agisoft Photoscan project file (PSZ format).
Natural Colour Image with 3cm spatial resolution (GeoTiff, KML and ECW format).
Digital Elevation Model with 6cm spatial resolution (GeoTiff, KML and ECW format).
Ground Image of the Northern sector of the Survey Area
2 About the Survey, and the Equipment Used
The QuestUAV survey was undertaken on 26 August 2015 with a standard QuestUAV Surveyor Pro (see front page for the UAV) in a built up area close to Jeonjo, Southern Korea. The UAV was equipped with a gimballed Sony A6000 camera operating on a 2 second trigger. 1,350 images were acquired in total with an overlap of 80% in-flight and 60% side lap. The figure below shows the flight path and indicates the image overlap. (The irregular area to the top is the result of high ground reducing the overlap.)
The area of survey has 13 GCP’s and 6 control points for accuracy assessment and is contained within approximately a 1 square kilometre grid.
The UAV took off from the school grounds in the centre of the survey area and flew the area once EAST-WEST and then routed to a NORTH-SOUTH grid, all within a single fight. The UAV returned to the launch area for a parachute landing. The flight took approximately 45 minutes.
A crew of two was used for the survey; a pilot (N King) and a laptop commander (R Moore). The UAV was visible throughout the flight. Flight was autonomous from take off until the decision for parachute landing preparation.
Launching the QuestUAV Surveyor 200 (L) Natural colour image of the study area showing distribution of ground control points (R)
3 Image Processing
An A4 sheet was laid on the ground with an identifying mark in the centre of the sheet. The centre was referenced using high accuracy DGPS survey instruments returning mm accuracy.The image processing was completed in Agisoft Photoscan. The computer used took approximately 18 hours to complete the dense point cloud creation – the longest part of the processing.
Input for the image processing were the following 3 datasets:
A total area of 2.3 square kilometres has been processed. Details on the image processing can be taken from the Agisoft Photoscan Processing Report, which is part of our deliverables.
4 Image Accuracy
The outcome of the image processing was a high resolution Natural Colour mosaic with a spatial resolution of 3cm and a Digital Surface Model (DSM) with a spatial resolution of 6cm.
The accuracy error, calculated through the CP’s, throughout the mosaic was on average one pixel (ie the same as the spatial resolution).
The processed Natural Colour Image shows:
Land usage: Spread of buildings. Building and land boundaries can be clearly identified. Heights of buildings can be assessed.
Power lines routing and condition.
Roads and highways: Sizes, dimensions, road surfaces, barriers, road marking, dangers from signals and signage
Agricultural information: Field boundaries and field roads can be identified. Crop types, crop status and crop health can be assessed. Presence of illegal crops or illegal usage of land can be detected.
River boundaries and conditions: Conditions of river structures, flow of water and water colour.
Detail from the Natural Colour Image
Different crop types of agricultural areas can be easily identified.(L) Markings on a road intersection. (R)
4.1 Digital Elevation Model
A Digital Elevation Model (DEM) is a digital representation of the elevation of a terrain. Each pixel of a DEM contains an elevation value. Our DEM of the study area shows a minimum elevation of 45 meters and a maximum elevation of 105 meters above sea level. The terrain rises from the centre line of the study area in both directions, Northwest and Southeast.
Digital elevation models are the basis for in-depth terrain analysis and hydrologic calculations, like for example:
Determining the slope of roads
Calculation of height profiles along roads
Derivation of contour lines
Calculation of hill slopes and determination of aspects
Determining watersheds and stream networks
Modelling flow accumulation and runoff volumes
Please note there is no universal usage of the terms Digital Elevation Model (DEM), Digital Terrain Model (DTM) and Digital Surface Model (DSM) in scientific literature. In most cases the term digital surface model represents the earth's surface and includes all objects on it. In contrast to a DSM, the digital terrain model represents the bare ground surface without any objects like plants and buildings
In our case we have produced a Digital Surface Model (DSM), showing the elevation of all objects on the ground. A DSM can be used as basis to derive a Digital Terrain Model (DTM).
The accuracy of the DEM was assessed by comparing the elevation values of the ground measurements (GCPs and CPs) with the DEM values at the ground control locations. The table below shows how good the elevation of GCP and DEM match. The average difference is between 0 and 3 cm.
5. Land Mapping and Elevation Analysis
The survey can return a vast array of data in terms of land mapping, infrastructure, elevation change, agriculture, social change, road usage, and many more subjects. The following sub-chapters show examples of an in-depth data analysis.
5.1 Mapping the Location and Size of Buildings The location and size of buildings or other objects on the ground (field boundaries, ponds, parking areas, etc.) can be precisely determined on the basis of the Natural Colour Image.
Each pixel of the Natural Colour Image has a unique geo-coordinate and represents an area of 3 cm x 3 cm. With such a high spatial resolution, roofs can be easily identified and digitized inside a Geo-Information System (GIS). A GIS allows to automatically calculate the roof area.
Example of mapping greenhouses and determination of roof sizes.
5.2 Determining the Slope of a Road
The slope is a measure of the steepness of a road and can be determined on the basis of a Digital Elevation Model (DEM). Slopes are calculated by determining the change in elevation along two points. Height profiles allow us to understand the elevation changes and show the ups and downs along a track. The figure below shows the height profile along a road section in the north-eastern corner of the study area.
The elevation changes in south-north direction from 49.2m to 53.8m, along a length of 346m. According to the common slope formula (slope = rise/run x 100), the slope of the road section is 1.3 %.
Please visit our dataset page for more examples - Datasets
New fleet of Q-100 DATAhawks arrives in South Korea
A fleet of DATAhawk mapping UAVs have arrived in South Korea, ready to perform mapping duties as part of an ongoing, large-scale cadastral survey mission by government departments.
A nationwide effort to create datasets that can be used by government and citizens looking to monitor and manage a wide range of land uses has been underway for some time
The DATAhawk fleet will bolster those efforts, with a flight time of up to an hour and a QX series imaging sensor giving a 3.2cm GSD - allowing fine ground details to be captured easily. The aircraft is easily launched by hand or from the AirDock system (seen below) and comes as standard with parachute recovery for landings.
HELImetrex - a QuestUAV Australian partner - is hosting the first Pix4D User Workshop in Brisbane.
This is the perfect opportunity to meet face-to-face with HELImetrex experts and develop your knowledge.
The course runs on September 7th, 8th and 9th.
Day 1 (from 9AM to 5:30PM)
From Images to 3D Points (Theory)
Pix4Dmapper Outputs (Compatibility with CAD/GIS software)
Georeferencing and Accuracy
Pix4Dmapper Best Practices
Pix4Dmapper Basic Demo
Hardware and Processing Time
Future plans of Pix4D
Day 2 (from 9AM to 5:00PM)
Flight 1 (Copter)
light 2 (Fixed Wing)
Hands-on exercise session:
Create a project
Add Manual Tie Points/GCPs
Evaluate the Quality of the project
Add Scale Constraints
Merge 2 projects
Q: What level of experience is the Workshop intended for? A: This workshop is geared towards beginner and intermediate users. It covers topics such as best practices for data acquisition and the different processing options. While the workshop can be attended without any previous exposure to Pix4Dmapper, we recommend having processed at least 1 project to get the most out of the event.
Q: Is lunch included in the Workshop price? A: Lunch, coffee/tea, snacks and water are included in the price.
Attending the Workshop also gives you access to a 30-day license of Pix4Dmapper Pro
As we run through the process of testing and proving our new PPK product, Nigel King - the drive behind the company - felt the best way to convey the accuracy and testing schedule information was to run a blog with fuller details and faster status updates.
One week later - QuestUAV present the launch of our new Technical Overview Blog, which will begin with PPK and run on with insider details of our other products and services as they present themselves.
For now, the plan is to cover PPK with the topics:
What is really achievable in terms of Accuracy and Ease of Use?