LiDAR Needs and Use Survey Results
By Shelly Sentyrz, MN Department of Natural Resources
This spring the LiDAR Research and Education subcommittee of the Minnesota Digital Elevation Committee conducted an online survey to assess how elevation data collected using LiDAR technology is used or intended to be used throughout Minnesota. The intent was to better understand the type(s) of training needed to facilitate the use of this high-quality data. Thirteen multiple choice and open-ended questions provided a snapshot of current LiDAR use in the state.
485 respondents from 180 different zip codes completed the survey. A grand majority worked in local, state, or federal government (82%). Watershed organizations (6.41%) private sector, (5.18%) and SWCDs (2.18%) comprised the next largest groups of respondents. The primary activities of these organizations focus on natural resources, water resources, engineering, and agriculture.
There were no prominent patterns to frequency of LiDAR data use. A full third of those responding had never used LiDAR in their work, but saw value in and looked forward to doing so. Another third used LiDAR data once in a while. The final third used it often or daily.
Almost three quarters of users (71%) employ GIS software to work with LiDAR data. CADD (12%) and simple desktop or online viewers (12%) comprise the majority of other software used. The small remainders of respondents use industry-specialized software (e.g. mining, urban planning).
The most prominent use of LiDAR data in Minnesota is for water resources projects (59%). That said, 53 different uses or intended uses were cited by respondents. The most often-mentioned uses included hydrologic analysis, detailed elevation for site planning, wetland mapping, engineering, and vegetation analysis. Thirty-five real-world uses of LiDAR data were listed. Watch for links to these projects on the above website in months to come.
Numerous respondents described experimenting with LiDAR data in new problem-solving arenas. One example included mapping historic mining features on a landscape, thus greatly reducing archeological fieldwork. A second is analyzing the sustainability of tree species planted after flood events. A third is the determination and adjustment of ecotype boundaries.
The skill level of a user largely determines the LiDAR data products they create or use.
Contours and Digital Elevation Models (DEMs) are the most popular derived products, used by over one third of respondents, likely because these products are ready for consumption in online viewers and in ArcGIS. Hillshade and shaded relief products are popular, as well (15%). Other products mentioned include Triangulated Irregular Networks (TINs), point clouds, and intensity imagery.
As users progress from viewing to analyzing LiDAR data, they tend to process the “original” LAS files to meet their needs. A full nine percent of respondents were unsure of what products listed in the survey were or how they might be used.
Review on usefulness
Nearly two thirds (64%) of respondents found LiDAR data useful or essential to their work. They cited reduction of time spent on projects, reduced site visits in preplanning phases, and more accurate cost estimates and project outcomes as grounds for their statement.
Two percent did not find it useful. They commented that the time spent on computers was better spent in the field; data needed further processing to make it as reliable as a site visit.
The remaining third (34%) of those responding had either not used LiDAR or had not used it enough to gauge its usefulness.
When asked if LiDAR data saved users money, 46% replied yes, 45% said no, and 9% were unsure. Answers to this question may not accurately reflect the cost-savings of LiDAR use, however, because some respondents who have not used LiDAR may have replied “no” instead of “unsure-have not used”.
Training and information needs
With the wide spectrum of LiDAR knowledge and use, training needs are numerous and varied. A quarter of respondents want training in the basics of LiDAR products and use. Other training requests mirror the specific applications folks intend for LiDAR: 20% are interested in water resources-based training, 18% desire terrain analysis training, 18% wish for wetland mapping classes, 12% want instruction in ecological applications, and 7% prefer training in engineering uses.
Preference for training mediums is as wide-ranging as for training topics, though a great majority agree hands-on courses – either classroom or virtual classroom – are favored. Cost is the overwhelming limiting factor in training attendance.
Those comfortable with the basics of LiDAR data prefer a LiDAR training portal containing recorded events, self-teaching materials, and links to project examples.
As is common with other new technologies, the survey indicates that there are currently pockets of LiDAR expertise within Minnesota’s spatial data community. Traditional users of elevation data have established protocols for working with LiDAR data, but the increasing availability of this high-detail homogenized LiDAR dataset is also spurring innovation in other specialties. New uses and methods are likely to evolve, and that evolution will depend on exposure to existing knowledge. For this reason, the MN LiDAR Research and Education subcommittee of the Minnesota Digital Elevation Committee will discuss a “one stop shop” web portal at the annual MN GISLIS conference on October 5th-7th, 2011.
For more information, contact Shelly Sentyrz at Shelly.Sentyrz@state.mn.us, (218) 308-2374.