2014 will herald a new world where unmanned airborne systems (UAS) will perform a host of useful tasks for government and private industry. It is not a bad idea for those involved in collecting and using geospatial data to begin thinking of the implications.
The most obvious data products from UAS flights and subsequent data processing are orthophotomosaics, digital surface models (DSMs) and point clouds. With post-photogrammetric processing and non-RGB (i.e. visible light) sensors, even more products are possible.
How will these capabilities affect geospatial professionals? For surveyors, UAS will make it possible to survey larger areas in less time compared to using a total station or RTK GPS. With enough ground control, you could easily get ±5 cm (about 0.15 ft or 2 inches) or better horizontal positioning. The vertical accuracy is likely to be in the ±10-15 cm range. While it will depend on the UAS, flying height, camera type and ground control accuracy, the confidence level for these could be as high as 3 sigma. When you consider that conventional topographic mapping and even planimetric mapping is done using a sparse sampling of points, nadir imagery-based data products can remove a lot of uncertainty in the topology, quite apart from whatever positioning accuracy is possible.
For photogrammetric mappers, areas that were previously cost-prohibitive will become possible. Many photogrammetrists see the UAS as competition, but embracing the technology can create new opportunities. It will require different software. High overlap (75%) or more imagery at low heights (100-150 m typically) will require close-range photogrammetric techniques combined with vision software. Ground control will be planned and used differently, and some clients might not even require ground control. Models of areas of up to 1,000 acres (or more) may be georeferenced to ±2 or 3 m without ground control and with the same internal consistency noted above.
For all geospatial professionals, the technology will open new markets. With the rapid response time of UAV mapping and relative weather independence, new opportunities for time-sensitive deliverables can be exploited for applications such as construction monitoring, agriculture (especially with near-infrared or infrared capabilities), erosion monitoring, post-weather event mapping, mapping of sites affected by disasters, explosions, accidents, crowd and general event documentation, perimeter mapping at areas where security is being planned and evaluation of sites where pollution violations are likely (farms, industrial plants, chemical storage areas, etc.).
The applications in agriculture are particularly worth noting. While not agronomists, geospatial professionals can deliver quite a bit of data to assist in the planning of agricultural sites as well as to facilitate agricultural operations by monitoring for stress, pests, disease, harvest estimation, erosion evaluation after harvest, and other factors. RGB as well as infrared cameras can monitor crop health. Many of these functions are already being done with ground based mapping systems and satellite technologies. Using the UAS platform to manage these services removes some of the obstacles such as clouds (typical flying heights are under most clouds), light rain and winds (some UAS can fly in winds up to 35 or 40 mph). With satellite technologies, you are dependent on satellite schedules and weather. With a UAS, you’ll be able to fly whenever you want with much less sensitivity to the weather.
New opportunities are also possible with volume measurements in landfills, mines, sand and gravel operations, shorelines, borrow and fill areas for construction, and cost and progress mapping in projects that involve sitework. Planimetric mapping can even be used for cadastral surveys. While it is easy to see the mapping component for reconnaissance, the accuracy of well-controlled UAS surveying makes it competitive with other methodologies, at least in certain areas, due to its accuracy, cost and speed.
Some of the other applications that are being explored with UAS include leak and “boil” detection around dams and levees, forest fire mapping (with and without frequent visitation), wildlife evaluation and inventories, utility damage mapping, low environmental impact inspection of endangered wildlife, and scrutinizing checkpoints, ships approaching ports, and vehicular flow. Through software that is capable of detecting change in subsequent mapping cycles, the art and science of using visitation mapping to generate information in varied applications—such as disaster response, construction monitoring, environmental mapping and even rescue operations—has been hypothesized.
The sky’s the limit, regardless of where the UAS flies.
Image: The Gatewing X100