Eastern Massachusetts Higher-Resolution Lidar Data Now Available to the Public

Elevation lidar data from the entire Eastern Massachusetts is now available at no cost to the public —including any governmental or private entity — through the MASSGIS website. A total of 5,125 square miles were surveyed and encompass roughly 50% of the entire Commonwealth. All of Cape Cod, the Greater Boston region, including the North and South Shore, and a good portion of Central Massachusetts elevation lidar data were all acquired during the Spring of 2021. 

MassGIS, the Commonwealth's Bureau of Geographic Information, is charged with collecting, preserving, and disseminating geographic data. The agency serves the public and private sectors, supports emergency response, real-estate research, environmental planning and management, transportation planning, economic development and engineering services.

"Our collaboration with the USGS and NV5 Geospatial enables us to deliver valuable data that can be applied in numerous ways. This freely available data can help municipal and state agencies improve infrastructure designs and gain a better understanding of structures in their jurisdiction, make communities more resilient, model stormwater volume and areas at risk from flooding more accurately, and ultimately minimize the spend for all interested parties valuable through economies of scale in data acquisition," noted Neil MacGaffey, retired director of MassGIS, who initially led the project.

Consistent, highly detailed information about the local geography and structures provide the foundation for so many decisions that city and state leaders, public utilities and private companies have to make on a daily basis – from helping keep power on and preventing flooding, to building new roads and bridges that keep citizens connected. The elevation data now available on the MassGIS website can be used for a number of purposes including:

• Engineering-grade derivative analytics using lidar point cloud data and one-foot contours
• Fusion of colorized lidar point cloud data and imagery for true-to-life visualization of the geography
• Identification of vegetation, transportation, utility and hydro features using point cloud data
• Building and ground surface modeling for infrastructure and transportation projects
• Digital elevation modeling (DEM), which provides the cornerstone dataset for a variety of geospatial analysis opportunities
• Bare earth modeling using the QL 1 specification for a topographically accurate representation of the terrain
• Shaded relief mapping that captures both natural and built/artificial features to understand elevation variation in the landscape
• Tidally coordinated lidar data for additional elevation and shoreline delineation analysis
• Elevation derived hydrography (EDH) to improve the accuracy and precision of hydrologic network mapping 
• Vegetation analytics, featuring leaf-on and leaf-off imagery, to support inventorying of trees via classification and measurement of individual trees
• Normalized digital surface modeling (NDSM) to determine the absolute height of objects and surfaces 

As part of 3DEP, federal grant funds for the project were provided to a partnership coordinated by MassGIS, between the Massachusetts Department of Transportation, the Executive Office of Energy and Environmental Affairs (EEA), the Executive Office of Technology Services and Security (EOTSS), and the Cape Cod Commission.

Recent Lidar Data Acquisitions are Four Times More Detailed

The USGS, on behalf of MassGIS, contracted with NV5 Geospatial in 2021 to acquire the eastern portion of Massachusetts at a topographic quality level (QL) 1 lidar specification, which is four times more detailed than previous specifications (QL2) as highlighted in the Lidar Terrain Data Index below. 

The image is a visual comparison of lidar point density specifications. Higher densities, like QL0 and QL1 data, capture more features and details, which allows for more complex data analysis and subsequently provides more value to a wider range of applications than data of a lower point density. 

 MassGIS reported in their newsletter that with the newly released data, “the entirety of Eastern Massachusetts has a single, consistent elevation dataset. Furthermore, the MassGis newsletter noted that before the 2021 data acquisition, “Massachusetts had previously been a patchwork of numerous projects with varying levels of accuracy” and are now referred to as Legacy Lidar Terrain Data.

The QL1 and QL2 data covers the state as seen in this index map. 

MassGIS was also selected to provide new 15cm (6in) 4-Band Orthophotography for the entire Commonwealth. Having imagery and lidar collection in the same season provides tremendous value in consistency between the two datasets. The imagery data is also available through the MassGIS website.

MassGIS recently announced that a new lidar data collection across 5,125 miles of Eastern Massachusetts has been completed by NV5 Geospatial and expects the new orthoimagery from the data acquisition will be available in the first quarter of 2024. This new data was acquired using QL1 lidar specification.

The detailed data – also collected as part of the U.S. Geological Survey (USGS) 3D Elevation Program (3DEP)– uncovered 1,000 primary addresses and over 10,000 structures previously unidentified by imagery alone, offering insights the Commonwealth can use to support emergency services, property tax assessment and boundary infringement inquiries, and saving time and money required for additional boots-on-the-ground examinations.

In addition, the collection provides useful elevation data to support infrastructure, transportation and utility projects; improve the accuracy and precision of hydrologic network mapping; and classify and manage structures and vegetation. For example, the NV5 Geospatial lidar collection along the eastern coast of Massachusetts supports use for the National Hydrologic Dataset, which maps the water drainage network of the United States highlighting features such as rivers, streams, canals, lakes, ponds, coastline and dams. NV5 Geospatial hydro-flattened the digital elevation model (DEM) to identify culverts and pipes, and show the directionality of the water resources. 

“This new lidar survey replaces data from about 10 existing ad hoc elevation mapping projects completed over the last 25 years by various public agencies, each with differences in coverage, accuracy and point density,” said Peter Grace, GIS Analyst and 911 Team Lead for the Massachusetts Executive Office of Technology Services and Security (EOTSS). “Earlier lidar collections provided important information for specific projects, while our annual imagery surveys gave us a view of the vegetation and structures across the eastern portion of the Commonwealth. Our ability to collect lidar data more consistently and a higher level of mapping detail through 3DEP is delivering value-added findings that can benefit all stakeholders that rely on this type of information.”

Use Cases for Elevation Data

The below image is a lidar point cloud and lidar-derived bare earth surface model colored by point classification of downtown Boston. Lidar data is especially useful for proximity analyses with applications ranging from urban planning, hydrology, forestry, and transportation engineering.