A picture tells a thousand words. An orthophoto tells a thousand words and enables a thousand measurements. Points can be defined in terms of co-ordinates. Lines (vectors) can be measured and digitised. Areas can be accurately measured.
An orthophoto is a scale-corrected 2D aerial photographic map. It provides a totally comprehensive background suite of data which is often used to interpret and supplement other data types and thematic layers. Scale distortions due to tip and tilt of the camera at the time of exposure, and relief displacement, the rise and fall of the terrain, are removed from the imagery prior to publication as an orthophoto.
The orthophoto is widely used in Geographic Information Systems. It is the most cost-effective map product to obtain precise georeferenced information in a 2D environment. Production time for digital orthophotos has been greatly reduced by the adoption of a fully digital workflow. The increasing demand of higher resolution imagery requires solutions for faster distribution, smarter and innovative viewing capability as well as cost-effective data storage and management.
Orthophotos are widely used in urban planning, infrastructure development, property development, civil and water engineering, parks and gardens management, agriculture, forestry, mining, renewable energies, disaster recovery, insurance and coastal management to name just a few applications.
A range of orthomosaic products to match different accuracy needs and turn-around times
Premium orthomosaic product of high radiometric and geometric quality
This top of the range seamless ortho-mosaic product is generated using a precise stereo-edited digital terrain model in order to provide very high geometric accuracy. Advanced colour balancing techniques and software ensure a radiometric seamless product. Three and/or four-band imagery in 8bits or 16bits can be produced.
This product is suitable for the widest range of 2D mapping applications. The philosophy is to produce a single product that can service every need. Engineers, surveyors, infrastructure and construction workers need decimetre accuracy or better to control major engineering planning studies or on-ground works. Coastal management authorities need best possible water penetration and absence of sun glare to monitor seagrass growth, so we fly runs and process carefully, specifically for water penetration.
Industry standard orthomosaic product
This semi-automatic ortho-mosaic is produced with the same care as our Ortho Plus product with a little more automation and optimal Quality Control. Three and/or four-band imagery can be produced. This product is most suited to fast production and in applications where currency is a high priority.
Fully automated orthomosaic product
This is a properly triangulated and ortho-rectified product and generally supplied to the full extents of the photography flown which gives a “bonus” area to the client. While, accuracy is not quoted, blemishes will rarely be evident in 50cm pixel imagery. Fast Ortho products are quick turn-around, with a focus on automation.
Fast Ortho is particularly useful for applications in which speed of delivery and currency are the highest priority. This can include areas of dynamic change, monitoring progress of a widespread event, or documenting widespread damage as quickly as possible. In some types of terrain such as deserts, Fast Ortho can approach the same level of quality as Standard Ortho or even Ortho Plus. This is because such areas do not contain large water bodies, forests or tall buildings, which require more manual attention.
Documentation of bushfire events is a common application of Fast Ortho. Imagery must be flown in good conditions to ensure comprehensiveness and long-term utility but must be flown and processed as quickly as possible to ensure that follow-up services have the information they need at their fingertips. The Fast Ortho for such an event, is often flown as 4-band (RGBI) imagery to document severity of burns and effects on vegetation. This service is regularly used by State Governments and insurance companies.
Fully automated with critical capture timing
Ideal for time-critical projects, the ortho-mosaic product can be delivered to the client in 1-3 days depending on the area covered. Accuracy is not specified and depending on the capture conditions, smoke, haze and water glare may be present in the end-products
In 2012, Aerometrex mapped the flood pulse of a major flood in the Broken Creek area of Victoria almost daily. The movement of the flood pulse down the river system was imaged 7 times in 12 days to determine the need to evacuate towns in its path. We performed the data capture and processed each coverage overnight to deliver the imagery the next morning.
This product is of great relevance to government agencies, insurance companies, police departments, coroners, and various State Emergency Services.
Free of building distortions/lean
Building lean (radial distortion) can obscure ground level features in orthophotos. Our True Ortho product corrects relief displacement for buildings as well as the terrain surface, thereby removing building ‘lean’ in imagery.
This is an ideal product used by many CBD districts and inner city councils, architects and asset managers. City councils can highly benefit from True Orthos to assess the condition of features such as pavements in a CBD area. Similarly, asset managers can use this product to map locations of signages, road markings, etc.
A raster of elevation values that can be edited to a Digital Terrain Model (DTM) or Digital Surface Model (DSM)
Elevation models of all types are automatically interpolated from extremely dense 3D point clouds which are extracted from aerial imagery. The best results for DTMs and DSMs are obtained by high-quality aerial mapping cameras with a wide-angle geometry. Best accuracy is achieved by applying advanced algorithms for image matching and data filtering.
A Digital Terrain Model (DTM) is a representation of the ‘bare-earth’ terrain surface. It is used in the production of other data types such as orthophotos, and is an important stand-alone product, enabling calculation of volumes (cut-and-fill / stockpile), slope and aspect, etc. The quality of a DTM is dependent on various factors relating to flying specifications, pixel size, camera geometry and processing software parameters as well as degree of editing needed. The capture of break lines where appropriate is essential to obtain a perfect fit of a DTM with the real-world.
Any application which requires accurate data on the shape, size and orientation of landforms needs DTMs. This opens a broad range of applications across civil construction, water services, bushfire modelling, engineering, mining, topographic mapping, recreation, defence, etc.
Premium Digital Terrain Model of engineering accuracy
DTM Plus is our top of the range Digital Terrain Model. This product is a result from the interpolation of extremely dense 3D point clouds which are extracted from the imagery, coupled with skilled operator review in 3D. It is fully stereo-edited and 3D breaklines are captured at sharp changes of slope to obtain a perfect fit of the DTM with the real world. The absolute accuracy provided is suitable for engineering-type projects where accuracy is a critical factor.
Industry standard, Stereo-edited Digital Terrain Model
Our Standard Digital Terrain Model is a stereo-edited regular grid that represents the ‘bare-earth’ terrain free of buildings, vegetation and other non-ground objects. Major break-lines can be collected and supplied.
Fully automated Digital Terrain Model
Raw 3D data is generated from aerial imagery by advanced stereo-correlation and image-matching software. Advanced automatic filtering algorithms are then applied to remove 3D points that may lay on top of buildings, vegetation and other non-ground objects.
A Digital Surface Model (DSM) is an elevation surface which includes buildings and trees as well as the bare terrain surface. DSMs are widely used in applications that require line-of-sight analysis, especially in telecommunications. The applications include placement of antennas for TV, wireless networks, mobile phone towers, microwave towers and others.
Our Digital Surface Models contain elevations of natural terrain in addition to the top of buildings, trees and any other objects. This product is analogous to the LiDAR ‘first-return’ elevation model. It is suitable for line of sight analysis, building extraction and transmission line obstacle analysis.
Aerometrex has generated large DSMs from some of its regular imagery coverages.
RAW frames for input into photogrammetric software
Mapping companies, surveying firms, property developers, architects, construction firms and building modellers find this information invaluable. The triangulated raw frame is the source data for many types of downstream data products. Organisations with internal photogrammetric mapping capabilities may prefer to use their own staff to generate these products.
Government agencies with an internal mapping department may require raw frames to produce specific product types for which they have specialist expertise, such as mapping tree species or crops.