Aerial Survey Territory

Management, Control, Security

Monitor a land area from above using optimized planning saves time, money and energy in all the operations of Management, Control and Security. Generating and updating bi-tridimensional models can be documented variations, criticality and act quickly. Today, the area is documented without a systematic method via instrumentation too onerous as the use of helicopters and planes and large format camera suitable for high altitudes, although the area to detect maybe is linear as the course of a river or however little extended as landslides. Kim proposes an economic survey system, all-around and repeatable, which regularly records the status of the territory on a regular basis or one-off measures by unmanned aircraft and the best sensors available today from photographic to multispectral and thermal. A 3D model time is generated with data collected and semantically evaluated by comparing it with the plan of the work, making possible the detection of significant deviations. The post-processing allows to exactly overlay the work plans on captured images distinguishing permanent structures and what is construction equipment such as cranes and trucks. The building owners so can continuously adapt their planning to current needs.

The case study: Stabbia (LI)

Conduct Operation

Shooting was planned in conjunction with the client in anticipation of surveys on a regular basis to monitor the state of fact and territorial developments along river auction of about 6km. Program the same survey at different times and on the same flight plan results in a saving in control and security of the site resulting in cost reduction.

Value Added

Overflight by UAV (unmanned aerial vehicle) has guaranteed a fast and effective security and planning of prevention activities of hydrogeological instability phenomena. Mappings were made with centimeter ground resolution and create specifically geographic information systems to support the management and the securing of the levees. The cost for this type of service is less than other means of aerial survey also by an order of magnitude.

Documentation

Operations periodic and systematic overflight enable you to generate more consistent and reliable documentation, useful for monitoring in the medium term. Continuous and easily comparable documentation with GIS tools by the customer ensures a more efficient management of the territory and the best prevention tool. stabbia2

The Systematic territory monitoring

The systematic territory monitoring allows the comparison of two or more aircraft mosaics of the same site and with the same flight plan (shooting angle, ground resolution, flying height, etc.) to obtain photographic elevation models of the site (and multispectrals) different between them only for the variable time. The changes, evaluated and interpreted unequivocally describe and quantify the changes taking place. The product key is the rigor and customization on the real needs, not by chance using GPS ground stations and specialized operators in close contact with the client.1. The first step is the rigorous acquisition of air data on a regular basis of the site, the post processing and photogrammetric recording with ground control points.2. Following the validation of the models made by Image Correlation algorithms that overlap mosaics obtained at different times pixel by pixel. The confidence value indicates the correctness of the relief and the transition to the next stage.3. The third step is the Change Detection in which we analyze in detail the variation between models at T0 and T1, determining matches missing as presence / absence of structures, dimensional changes etc4. The subsequent analysis becomes in the specific variations, considering for each change of interest ‘shooting scenes, multiple sources, multiple elements in general, as well as models of the terrain radiometry.5. The last step is defined Site Model Updating, changes in interest vectorized and incorporated into the new model.

Hydrogeological risk management and flooding

The dense mesh of points allows accurate modeling of the slopes, riverbeds and mountain basins, as well as riverside areas, and all the elements exposed to landslide risk and / or flooding. The photogrammetric survey associated with contextual multispectral data allows to monitor the evolution of the active landslide bodies considering the progressive magnitude and direction of shifts and then the real conditions of risk. The multi-temporal comparison between DTM acquired at different times helps to identify areas prone to subsidence or uplift and to estimate the rate of vertical deformations, representing monitoring technology more suitable in the case of extended gravitational phenomena lenses active type.