Mapping and analysis

The data is used to generate maps and perform geographical analyses. We use laser scanning extensively to assess terrain stability and conduct change analyses.

We have access to several types of laser scanners with different ranges, which allow us to measure objects both at close range and at long distances. Our Riegl scanner can measure up to 2,000 metres and is particularly suitable for natural hazard projects where there are often long distances to the objects.

Laser scanning is often combined with other mapping methods such as multibeam sonar, GBInSAR and photogrammetry to achieve comprehensive data collection and analysis.

Cautus Geo utilises NORBIT - iWBMS multibeam echo sounder. This sonar is small and lightweight, making it suitable for mounting on a small boat. With an adjustable frequency from 400 kHz up to 700 kHz, the sonar is suitable for mapping in shallow water.  

Our iWBMS multibeam sonar has a 1-degree transmitted beam. At a frequency of 400 kHz, the footprint on the bottom will be made of an emitted beam of 0.9° x 0.9°. 

iWBMS has an integrated motion sensor, Applanix WaveMaster II, which outputs pitch, roll and heading. Heading is calculated using two GNSS antennas that have a baseline of 2 metres. One of these two GNSS antennas will also be used to position the boat. In order to get the highest possible accuracy in the positioning of the multibeam echo sounder, we will use CPOS corrections in real time. 

One source of error for underwater measurements is uncertainty in the speed of sound in the water column. If the water is layered with different temperatures/density, the layers will have different sound velocities. To control this, we will use a sound velocity meter that measures the sound velocity in the entire water column.  

Depending on what density the customer wants on the measured points, the width of the area mapped by the sonar and the speed of the boat can be adjusted. If a high density of measurement points is desired, the mapping will take longer than with a lower density of measurement points. 

The delivery will consist of x, y, z point cloud and report from the mapping. 

In order to get good data, we are dependent on there not being a lot of wind and waves when we map the area.  

InSAR (Interferometric Synthetic Aperture Radar) is an advanced radar-based technology that uses interferometry to generate precise and detailed images of the Earth's surface. This technique combines radar images from the same location, taken at different times, to measure small changes in the distance between the radar and the Earth's surface over time. This makes it possible to measure deformations on land with extremely high accuracy.

The InSAR method can be used both from satellites and using ground-based systems.

Cautus Geo has been using ground-based InSAR since 2012 in various acute incidents and for more long-term monitoring. Ground-based InSAR means that the radar is placed on the ground instead of in the air or on satellites. This makes it possible to study changes in the terrain with high precision. Ground-based InSAR is used to monitor deformations and movements in the Earth's crust, for example in connection with earthquakes, land changes, mining activities or construction projects. It is also used to monitor infrastructure such as roads, bridges and dams to detect early signs of deformation or failure. InSAR is thus of great importance both for geoscientific research and for practical applications in engineering and risk assessment.

Cautus Geo currently operates various drones for photogrammetric and laser-based mapping of structures and land areas. By using drones and advanced methods, we achieve high accuracy, which is essential for change analyses.

To support or supplement photogrammetric mapping, we also use other surveying methods, such as laser scanning. In addition, we use bathymetric mapping methods, which make it possible to map and analyse areas both above and below water.