The E57 LiDAR Data Format Moving the LiDAR Market Forward

Turn on any brand DVR, connect your standard cable to any flat screen TV and youll enjoy the movie. Buy any printer to communicate with any computer and youre up and running in seconds. Data standards are a key component to market growth by expanding our choices among numerous manufacturers. We are empowered to select each component in such a way that maximizes the value of the overall system based on our individual criterion. The market grows as manufacturers fill every conceivable niche and in many ways our lives are made better. Finally this type of data standardization is coming to LiDAR system technology thanks to the dedicated efforts of the ASTM E57.04 Data Interoperability subcommittee.

Fig. 1 Riegl VZ400/Nikon D700 point cloud and calibrated image in TopoDOT

As the developer of TopoDOT, a popular LiDAR data processing software, Certainty 3D has long been concerned with the prior lack of data standardization among LiDAR equipment manufacturerspredominantly for tripod based (static) laser scanners. While airborne and mobile LiDAR systems provide data in the open LAS standard, static scanning systems were to a large extent proprietary. TopoDOT and other applications had to offer import tools for practically every manufacturers proprietary data format. In the all too common case of closed proprietary formats, it was necessary to develop ASCII to LAS data format converters. The ultimate consequences of this nonconformity were: 1) Users restricted to a single solution vertical workflow, 2) Lack of access to alternative processing applications and markets, 3) Time consuming data conversion, 4) Increased data management complexity 5) Frequent loss of information through reformatting, and 6) Increased costs.

With a clear need for a standard, the ASTM E57.04 subcommittee under the leadership of committee chairman Gene Roe developed a common data format for static LiDAR systems. For several technical reasons the structure of the LAS open data format currently used by airborne and mobile LiDAR systems was not well suited to static LiDAR data. The E57.04 committee had to start from scratch. Over several years of work, they have developed a reliable data format which included not only point cloud data, but all the relevant geospatial coordinate information and calibrated images attached to each scan.

Fig. 2 Leica C10 calibrated image with extracted line work in TopoDOT

Development of a solid data format however, does not necessarily guarantee adoption. Once again Gene Roe must be commended for his continuous promotion of the E57 standard within the LiDAR community. Several manufacturers such as Riegl Laser Measurement Systems and Leica were early adopters with each offering E57 as an export option. Certainty 3D implemented the E57 import function within TopoDOT early this year. However implementation is not adoption as it takes some time for users to reorganize their work flows. We are happy to report that we are seeing the first instances of E57 on a regular basis within our customer baseand the results have been impressive.

The E57 format has contributed greatly to processing productivity by exploiting the point cloud and associated calibrated imagery within the TopoDOT processing environment. For example, while the Riegl VZ series had always offered an open calibrated image data format the images taken with the Leica C10 were pretty much locked up within the Leica scanner. Now that Leica offers the E57 data export, these calibrated images can be easily exported along with their geospatial location and orientation information for use by TopoDOT/Microstation and other applications. The positive synergistic effect of calibrated images and point clouds on processing productivity cannot be overstated. The Certainty 3D application team has consistently found that the development of topography and general 3D models is approximately 30-40% faster with calibrated images as part of the data set. Congratulations to Riegl and Leica for supporting the E57 export format.

Not only is data import into TopoDOT from either a Riegl VZ400 or a Leica C10 laser scanner seamless, but the same workflows apply within TopoDOT regardless of the hardware source. This standardization of workflows provides data consumers, for example State Departments of Transportation, engineering companies and others, a broader range of choices with respect to vendors.

Fig. 3 E57 and LAS Open format facilitate data flow across Operations

Furthermore, our customers are exploiting the synergy of combined datasets from airborne and static LiDAR systems by using both E57 and LAS formats in the same project. For example, airborne data over a corridor might be supplemented with more accurate static LiDAR data on the road surfaces. Each data set alone might have been insufficient to meet the project requirements of coverage and accuracy. But using the open E57 and LAS formats both data sets can be imported into one CAD environment with the combined data exceeding project requirements.

Finally we are seeing E57 facilitate the flow of data beyond its traditional place in the survey department. No longer is all the data processed, 3D model built and shipped to engineering and design operations while the information rich data is never looked at again. Our TopoDOT customers are beginning to effectively use raw LiDAR data in downstream engineering, design and construction operations. The open E57 format has played a big role in making that possible. Congratulations and thanks to the ASTM E57.04 team!