by Thomas Schuster
Vancouver-based Aero Geometrics has been providing Geomatics services and expertise for local and international clients for over four decades now. During this period there have been tremendous technological advances as digital imagery has replaced film, digital data has replaced mylar and paper, and computers and software have replaced massive stereo plotters.
Over the years Aero Geometrics has successfully integrated this new technology and is now a leading provider of a wide range of services which include: Satellite Imagery acquisition, Ground and Aerial Survey, Terrestrial Laser Scanning, 3D Digital Mapping, Aerial Triangulation, Orthophoto, Volumetric Calculations, Aerial LIDAR and Hyperspectral Imagery.
The firm serves all levels of government, as well as engineer-ing, forestry, mining, and environmental consulting companies. Some of its more wellknown resource industry clients include Teck Resources, Pretium Resources, Copper Mountain Mining, Xstrata, Vale and many others.
“Our paramount focus is on client satisfaction; we go to all ends to do the job on time and never over budget,” commented Tim Daly, President of Aero Geometrics. “Over four decades of repeat clients will attest to our quality workmanship. We focus on exceeding the expectations of our clients in order to ensure their complete satisfaction.”
According to Daly, UAV (unmanned aerial vehicle) work is taking off (pardon the pun) and is one of the company’s biggest growth sectors along with Ground Based Laser Scanning solutions.
Last year the company has acquired several quad copters to complement its aerial acquisition capabilities. These quad copters are outfitted with a built-in Inertial Measurement Unit (IMU), as well as an Airborne Geo Positioning System (ABGPS) and high quality cameras that allow AeroGeo to service clients with tight deadlines, weather constraints or other unique requirements. The data the drones gather is processed via specialized software that can provide high quality solutions often for lower cost than stan-dard aerial surveys.
Using the more traditional fixed-wing or helicopter platforms, the company has completed thousands of aerial photo sorties through-out Canada and the world. Canadian projects range from BC to Newfoundland and include many locations in the Yukon, Northwest Territories and Nunavut. South and Central America as well as the USA and Mexico are also important areas of operation, with scattered work coming from Africa, Europe and the Middle East.
Aero Geometrics can capture stunning digital imagery in either RGB (Red Green Blue) or RGBI (Red Green Blue and Infrared) and will fly to provide pixel resolutions of between 5 and 40 centimetres. ABGPS and an IMU on the aircraft provide geo-referenced pictures which can then be mosaiced into large, seamless orthophotos. The company’s software can also display the imagery in stereo and be used to accurately capture planimetric detail, create contours or calculate volumes.
Planimetric elements in geography are those features that are independent of elevation, such as roads, building footprints, and rivers and lakes. They are represented on two-dimensional maps as they are seen from the air. These features are often digitized from orthorectified aerial photography into data layers that can be used for analysis and cartographic outputs.
Creating 3D imagery is one of Aero Geometrics many special-ties. After receiving imagery from aircraft, the data is triangulated using common points which are passed between photos and flight lines. Surveyed target control points are then introduced to orient the entire block of photos so that each stereo pair can now be viewed in 3D stereo using a soft copy workstation. A softcopy workstation displays a left and right image on a dual computer screen that uses polarization and 3D glasses to uniquely separate the left and right image allowing full 3D viewing.
From this point, all stereo models can be accurately measured and vector lines can be created to represent planimetric features. A DTM (digital terrain model) is then created by capturing break lines and spot elevations which accurately represent the ground surface. This DTM is then triangulated to create a surface mesh which can generate contours at various intervals and can be used to measure piles and calculate volumes.
Aero Geometrics also utilizes state-of-the-art Global Navigational Satellite Systems (GNSS) dual frequency receivers and has many years of experience conducting drill hole surveys, establishing target coordinates, establishing benchmarks and coordinating local survey points to UTM Nad83, which enables all data sets to be layered together, providing a comprehensive map of existing information.
Another quickly advancing field in remote sensing arena is Hyperspectral surveying. “These surveys are the MRI of the earth and can predict elements and associated indicators with many of them,” said Daly. “It is a highly specialized and an evolving technology.”
A Hyperspectral survey utilizes aircraft equipped with instruments that emit light. When the light hits a material, some of the light is reflected back, allowing it to be measured with a spec-trometer. The shape of the spectrum is like a fingerprint that reveals the chemical composition of the rocks. This has been found to be increasingly useful when looking for various types of deposits based on their alteration signatures.
Another technology that AeroGeo utilizes is LiDAR “Light Detection and Ranging.” This technology measures distance by illuminating a target with a laser and analyzing the reflected light. Lidar is a technology for making 3D “Point Clouds” of data which is a vector-based structure – each point in the cloud has an XYZ co-ordinate and some attributes called components like flight time, flight line, intensity, colour etc.
AeroGeo can also provide clients who already have LiDAR data with vector data using stereo LiDAR grammetry. This software enables linear data features to be determined from the 3D LiDAR images or “Point Clouds.” Vector data uses X and Y coordinates to define the locations of points, lines, and areas that correspond to map features. AeroGeo conducts aerial LiDAR surveys with both helicopter and fixed-wing aircraft, and expects to add a LiDAR capable drone in the near future. Airborne LiDAR has a precision of about 10 cm and a spacing of 4-to-40 points per square metre.
LaserGeo is yet another branch of Aero Geometrics that is rapidly advancing. The company uses German-made Z+F laser scanners that are world renowned for their quality, accuracy and durability. These laser scanners can capture over one million points per second with a precision of 1-to-2 mm and have an inbuilt HDR (High Dynamic Range) camera. The laser scanners are so accurate that the data produced can be used to document anything from structural movement, to building preservation, to CSI and Forensics.
Daly also commented that companies should be aware of the myriad efficiencies created by using the technologies now available. Accurate information will save time and resources by basing decisions on reality rather than guess work. Even greater efficiencies can be gained by overlaying different technologies where unique levels of information are stacked to provide an even clearer picture of potentials and efficiencies. These practices can not only save money, but may speed permitting, expose better alternatives and create additional value added solutions.