Explaining the Terrasolid Modules

Published On: February 28, 2022

by Martin Flood

Terrasolid – What You Need to Know to Know What to Buy

GeoCue Group is a designated North American reseller and support center for Terrasolid software, a relationship we have valued for over 15 years. In this role we offer sales, support, and training services to Terrasolid users in the US, Canada, and Mexico. This has allowed us to develop on-going relationships with many of the top lidar data producers in North America, many of whom have been using Terrasolid products for even longer than we have been working with them, some for more than 20 years. However, lately we have noticed an increasing number of new Terrasolid users emerging in the UAV/drone lidar space who aren’t just new to Terrasolid, but new to lidar in general. These new users have trouble navigating the different Terrasolid modules available and knowing what they need to buy to support their lidar workflows. Often all they are working off is a recommendation from a colleague to “go get Terrasolid, it is the industry standard”. So, we thought this month a beginner’s guide to the different Terrasolid modules and bundles would be helpful for these new entrants to the lidar industry.

Terrasolid Ltd. is a Finnish software company that has been developing software tools for terrain modelling, point cloud visualization, point cloud classification, feature extraction and 3D modelling for over 30 years. They sell a family of modules, each discussed in more detail below, that are plug-ins for Bentley’s MicroStation CAD platform or can be run inside the Spatix CAD engine (if you are not a MicroStation user). The software is primarily used by engineers and surveyors engaged in metric mapping across a variety of industries. The core of these users are lidar or photogrammetric point cloud producers, so Terrasolid is often referred to as “lidar” software, although it is much more than that simplified designation. The Terrasolid software suite covers a very broad range of tools and workflows of interest to drone lidar operators. To simplify things, the software suite is divided into modules that focus on specific areas or workflows. Knowing which modules they need is often the first hurdle a new user faces when looking to buy.

Here is what you need to know:

TerraScan

TerraScan is the core module you need to have if you are working with point clouds. It includes the point cloud handling engine that interacts with the CAD platform to provide the display of the data along with the core point cloud analysis tasks common to most workflows. Most importantly, it includes automatic classification routines for such critical features as ground (bare earth), buildings, power lines, and rail (amongst others). It has a full suite of interactive manual classification tools for use in point cloud editing. It also includes a robust macro system for scripting or batch processing of more complex point cloud tasks. Typical production shops will have one TerraScan seat per interactive editor or technician. TerraScan uses a floating license pool (as do all Terrasolid modules) so you need one license per simultaneous user. Generally, if you are buying your first Terrasolid bundle, you will be buying TerraScan “plus something else”.

TerraModeler

TerraModeler is TerraScan’s older sibling, having been developed first. TerraModeler creates surface models (TINs) from various CAD data sources, such as a point cloud loaded in TerraScan, traditional XYZ ascii mass point files or even graphical design file elements such as breakline vectors. The software offers versatile visualization options including colored shaded surfaces, contour lines, grids, colored triangle nets, elevation texts, slope directions and textured surfaces. Additional functionality includes the production of contour lines and lattice models in batch processing, modification of the TIN, creation of profiles, calculation of volumes, calculation of elevation or volume differences between two surface models, several labeling options as well as other tools for design purposes. Complete with various export options, TerraModeler is a versatile tool for many kinds of design and modeling tasks. Generally, if you plan to do any surface modelling or breakline work, you will need a seat of TerraModeler for each technician working on these tasks.

TerraMatch

TerraMatch is the “sensor calibration/geometric correction/point cloud adjustment” member of the Terrasolid family. TerraMatch is a sophisticated tool for improving the accuracy and quality of the raw point cloud. It compares laser data from overlapping flight (airborne/drone) or drive (mobile) paths and calculates correction values for the misalignment angles as well as XYZ location errors. The comparison and correction value calculation can be either based on surface matching or on different types of tie lines. Tie line matching comprises points or lines on horizontal, vertical, or sloped surfaces that can be used for matching flight/drive paths to each other, but also known point or line locations that enable the adjustment of the laser point cloud to control measurements. TerraMatch is the module you need if you plan to do any strip-matching or fitting of your point cloud data prior to classification. Since it uses a generalized data fitting and correction approach, it can be used with any sensor data provided you have time-stamped points and a corresponding trajectory. Since it is used only once near the beginning of the data processing workflow, you typically only need one TerraMatch seat or possibly one per sensor in your fleet.

TerraPhoto

TerraPhoto is the “orthophoto production” tool in the suite. TerraPhoto is specifically developed for processing images captured together with lidar data during a survey mission. The software enables the production of rectified images and ortho mosaics based on ground model that has been extracted from the laser data. The positioning of the source images can be refined by using tie points for image-to-image adjustment while ground control point can be involved for improving the absolute accuracy of the image block. With additional functionality, such as color adjustment options, the creation of selection shapes for several object types or areas (e.g. buildings, water), the inclusion of vector models for true-ortho photo production, TerraPhoto lets you create ortho photos of good positional and color-coordinated quality. TerraPhoto is mainly of interest to lidar producers who are not using a Structure from Motion (SfM) photogrammetric package such as Metashape or Pix4D for their orthophoto generation. If you are flying a drone lidar system and using one of these other photogrammetric packages, then you do not need to include TerraPhoto in your Terrasolid suite.

What Bundle to Get?

Terrasolid offers bundle discounts when purchasing multiple modules together, so it is always best to get the best combination to match your needs. For UAV/drone lidar operators, we recommend starting with a TerraScan+TerraModeler+TerraMatch bundle and then adding either additional TerraScan+TerraModeler seats (if you plan to do surface modeling inside the CAD environment) or just TerraScan seats (if surface modelling is not a primary task and you will focus mainly on point cloud classification) if you need additional technicians working on the projects. Unless you are already using MicroStation, the Spatix option is fine for lidar work and saves you having to buy Bentley’s CAD package. And of course, do not forget to budget for some training! If you are interested in adding the Terrasolid software suite to your drone lidar workflow, please contact us at [email protected] to request pricing or schedule a sales call.