What is the Precision of 3D Laser Scanning with Existing Conditions?

Building information modeling (BIM) and laser scanning has several uses in a variety of industries, including architecture, engineering, construction, and commercial real estate. With this data on hand, professionals have the reliable, real-time information about a property or structure. But for this technology to be useful, it needs to provide a great deal of accuracy. And not every laser scanner provides the necessary accuracy for important projects.

3D laser scanning is highly accurate, often achieving precision within ±2 millimeters or better, depending on the equipment, methodology, and environmental conditions.

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How Does 3D Laser Scanning Actually Work?

The primary way a laser scanner works is to send light pulses at high speed which reflect off objects and return to the scanner’s sensor (LiDAR). For each pulse, the distance between the scanner and object is measured by determining the elapsed time between the sent and received pulses. Each data point is converted to a pixel with a known x, y, and z coordinate.

Laser scans are taken in multiple positions around a site from varying viewpoints. Millions of data points are captured and processed into a point cloud, creating an accurate 3D as-built data set of the site. This all happens very quickly, with some scanners, like our Leica RTC360, capturing and calculating 2 million points per second with 2-4 mm accuracy.

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How Precise is 3D Laser Scan Data?

When you work with Existing Conditions, you can rest assured we work with only the most technologically advanced 3D laser scanning technology. We use a full spectrum of 3D laser scanning equipment from companies including Leica and FARO 3D. Depending on the project, we deploy the scanner that best fits the needs of the project.

Let’s consider the Leica RTC360 for example.

Under laboratory conditions, it has impressive 18” angular accuracy, as well as range accuracy of 1.0 mm + 10 ppm. Its 3D point accuracy is 1.9 mm @ 10m, 2.9 mm @ 20 m, and 5.3 mm @ 40 m. It gathers low noise data to allow for better images, with crisp, high-quality scans that are rich in detail and ready for use in a range of applications. It also has a measuring rate of up to 2 million points per second, as well as an advanced HDR imaging system. Ultimately, the creation of colored 3D point clouds can be completed in under 2 minutes per scan location.

When used on actual job sites, the accuracy will never quite be exactly what the manufacturer can achieve in a sterile lab environment. But by using advanced 3D laser scanning equipment like the Leica RTC360, our team has the confidence that we are using a tool designed to be incredibly accurate.

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What Deliverables Can Be Created?

Existing Conditions team of CAD technicians will produce custom deliverables for your project, ranging from point cloud data 2D CAD drawings, 3D BIM models, 3D mesh models, TruViews, and 3D virtual tours. Deliverables can be provided at any level of detail in a variety of formats including Revit, AutoCAD, ReCap, Navisworks, Civil 3D, BIM 360, A360, JetStream Viewer, and more.

Our deliverables are driven by your scope and your needs once we’ve completed laser scanning for your property or project. We customize our level of detail to suit your needs. For example, most clients request 3D BIM models or 2D CAD floor plans, roof plans, and exterior elevations. Some clients require additional information, including reflected ceiling plans and electrical plans.

When quoting the project, we provide you with what will be included in the drawings and models and what our scope will be. Before we create CAD drawings or a BIM model for you, our BIM managers will contact you to review the laser scan data when necessary to be sure we’re getting you as much situational awareness as possible.

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About Existing Conditions

Existing Conditions creates highly accurate digital models of buildings and sites using reality capture technologies such as 3D laser scanning and drone imaging. The point clouds, as-built drawings, and 3D BIM models we deliver are the essential tools architects, engineers, and developers need to make decisions based upon precise, real-time data. As the architecture, engineering and construction industry adopts more data-driven practices, reality capture technologies are becoming increasingly relevant.

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