Accurate elevation data is crucial for large construction projects and civil planning. The more accurate the elevation models, the more precise the planning, budgeting, and forecasting can be. This saves time, money, and prevents wasted resources and can drive projects to a speedier finish.
Today, new mobile surveying technology like our modular mapping payload, Nexys, provides engineers, planners, and architects the flexibility to quickly capture point clouds and generate elevation models at reduced costs and improved accuracy compared to traditional methods.
Light Detection And Ranging (LiDAR) sensors are the latest technology used for Digital Elevation Modeling (DEM) and is replacing photogrammetry or triangulated irregular networks (TINs).
TINs have also experienced improvements over the years and are useful for complex terrain or hydrological models. Today, modern LiDAR systems are often used to supplement existing TIN data for a more complete elevation model and to mitigate some of the shortcomings of TINs.
Modern LiDAR systems work by creating a “point cloud”, which is a 3D representation of the environment made up of millions of data points. A LiDAR sensor is mounted to a rotating gimbal which enables it to capture a huge amount of data extremely quickly. Each point is a highly accurate coordinate in 3D space. Combined, these points create a digital twin of the area being surveyed for elevation data.
Traditionally, surveyors deploy terrestrial LiDAR base stations and these are used in conjunction with GPS signals to accurately capture DEM data. The problem is that these surveying techniques are time-consuming and expensive. They’re also limited in the area they can feasibly cover within a given time frame. They’re more accurate than photogrammetry or similar extrapolative DEM methods, but they lack flexibility due to costs and time constraints.
The latest mobile LiDAR surveying technology in our Nexys system offers unprecedented flexibility and cost savings for elevation modeling. It uses the same fundamental technology as a terrestrial LiDAR base station, with the speed and modularity that only Nexys can offer.
A single Nexys unit can replace the following traditional DEM/DSM methods at a significantly reduced cost.
Aerial Photogrammetry
Aerial photogrammetry is useful for DEM, but the high hourly cost makes it less than ideal in many cases. It can also be time-consuming to manipulate the images for DSM or DTM requirements. After the photos are taken, they must undergo extensive post-processing to yield useful data for a DEM.
Terrestrial Surveying
Terrestrial surveying with base stations is also accurate, but this requires teams of highly specialized surveyors. It’s also time-consuming due to the meticulous movement of the stations, which adds to the cost and lack of flexible options during planning.
Traditional LiDAR Mapping
LiDAR is changing the way that DEM data is captured, but today, this is currently being done primarily through manual ground surveys or LiDAR sensors attached to manned aircraft, both of which are labor-intensive, slow, and costly.
A single Nexys mapping unit provides the same accuracy as these methods in many cases, but at a far lower cost. The data captured can also be seamlessly converted into DSM or other models to accommodate varying topographical requirements, such as vegetation or structural data.
Other LiDAR mapping solutions cannot quickly adapt to different surveying requirements. The Nexys was designed with complete modularity in mind, and the same unit can be used for a variety of mapping tasks, from mapping small areas by hand to autonomously exploring large expanses with a ground- or aerial-based robotic platform or drone.
Whether it’s mounted to a vehicle or attached to an aerial drone for larger elevation surveys, the Nexys adapts to any DEM scenario. This flexibility allows you to deal with a wider range of situations and project requirements without the need to purchase additional equipment or services.
Data is always the most useful when it can be easily integrated into your current workflow, and that’s another area where Nexys excels. All point cloud data is compatible with popular CAD workflows, geospatial data, and the industry-standard Trimble Reality Platform.
The Nexys performs all post-processing on-site without the need to send the data to the cloud first. The result is your team can ensure the data they have is sufficient and then immediately transfer it to a shared Trimble folder or other CAD workflow system after on-site post-processing.
This gives planners, engineers, architects, and stakeholders full control to immediately share and collaborate using the latest DEMs without any bottlenecks or inefficiencies. With Nexys, your data is never siloed or limited by proprietary formats.
If your organization is looking to improve the way it captures DEM data, contact us today for a personalized demo of the Nexys system.
Whether it’s for small areas, hazardous and GPS-denied areas, or large expanses covering acres, the modular Nexys can revolutionize your DEM workflow with speed, efficiency, and significant cost savings.