This Guidelines document provides a framework for the practical application of mobile LIDAR (Light Detection and Ranging) technology to a wide variety of transportation applications. These Guidelines are rooted in a strong theoretical foundation, but they were developed for a diverse group of transportation professionals who are not expected to be experts in mobile LIDAR technology. However, it is strongly recommended that an experienced geomatics person be involved throughout the entire process when using mobile LIDAR for transportation projects.
Recommendation: An experienced geomatics person should be involved throughout the entire process of using mobile LIDAR for a project.
Mobile LIDAR systems (MLS) are emerging as an important 3D measurement technology that can rapidly acquire a substantial amount of highly detailed, geospatial information. Additional sensors such as cameras, reflectometers, laser crack measurement systems, or inertial profilers can be mounted on the vehicle to collect additional information at the same time as the LIDAR data acquisition. The significant volumes of data obtained from these systems provide a valuable, yet challenging resource. Specifically, the key objectives of these Guidelines are to:
- Promote the appropriate and intelligent use of mobile LIDAR in transportation applications,
- Assist transportation agencies with the cost effective adoption of mobile LIDAR by lowering the risk of establishing this transformative 3D technology as standard operating procedure,
- Establish a common basis for communication between data providers and users in transportation agencies. In the case where a transportation agency will be collecting their own data, these guidelines will help communication between departments.
- Develop an easy-to-understand, management-level process, with guidance on quality management and specification of final deliverables,
- Establish that the data provider is to deliver adequate metadata and documentation of the methods used such that an independent, 3rd party can duplicate the results, and
- Provide recommendations on data management, storage, persistence and compatibility in order to ensure long term viability of captured datasets.
It is not the intent of this document to specify the methodology for “how” data providers collect and process data, or “what” equipment they use, but rather the focus is to establish the acceptance criteria for determining whether end products can be properly used for specific applications by transportation organizations. Implementation of new technology requires innovation, and overly prescriptive requirements can often stifle important future developments. To allow this innovation yet ensure that the data meets the end users’ needs, these Guidelines are by design performance-based, such that they are independent of the current state-of-the-art in technology. The intent is to avoid obsolescence, but still be relevant to today’s commercial off the shelf (COTS) technology.
1.1 Motivation and requirements for national transportation agency guidelines
As noted in the previous section, mobile LIDAR is an important technology that has major implications for the way in which geospatial data is collected, exploited, managed and maintained by transportation agencies. This active system of measurement can be used to obtain highly accurate 3D point data by safely driving a collection vehicle at highway speeds. As transportation agencies transition from 2D workflows to 3D model-based design and asset management the ability to make efficient use of mobile LIDAR will only increase.
Recognizing the potential value of this emerging and transformative technology to transportation agencies, the Transportation Research Board (TRB) National Cooperative Highway Research Program (NCHRP) has funded this effort to develop uniform Guidelines for the use of mobile LIDAR in transportation applications. This document will assist both transportation agencies and the service provider community with the introduction and adoption of this technology by establishing a published, standard reference and common basis for understanding and communication.
Currently each transportation agency must perform their own investigation of this sophisticated, 3D technology. This research is time consuming and inefficient as compared to the development of a national set of recommended Guidelines that both transportation agencies and data providers can refer to. This will lower the risk of adoption, and potentially the costs of use, since the service provider community will not have to invest as much in educating individual transportation agencies about the benefits of the technology and the demand for services will increase.
By developing a nationally recognized set of Guidelines, transportation agencies can establish requirements that are in their collective best interests, For instance, the subject Guidelines will require a comprehensive approach that includes a transparent quality management and reporting structure that places the responsibility on the data provider to certify the quality of the final deliverables such that an independent 3rd party can duplicate the results. Adherence to these principles is important regardless of whether a transportation agency collects and/or processes the data internally or uses an external data provider.
Transportation agencies can also require that the Guidelines are implemented by staff that are familiar with geomatics, but who do not necessarily have to be experts in mobile LIDAR, in order to obtain the desired results. A nationally recognized set of Guidelines will also avoid the issue of being influenced by a specific, local service provider or current technology. This will ensure that the Guidelines will remain applicable as the service providers and technology evolve over time.
A national set of Guidelines can also help to establish the focus on performance as opposed to methodology. By avoiding the specification of equipment, collection procedures and software in favor of determining whether the required accuracy for a specific application has been achieved, the Guidelines can remain relevant as the technology matures and changes.
Finally, a national set of Guidelines can address the critically important issue of data management. The volume of data associated with mobile LIDAR is not something most, if any transportation agencies have experience with centrally managing. In order to maximize the return on the investment in this technology transportation agencies are going to have to develop a data management strategy that insures timely and streamlined access to the data across the entire enterprise.