2023 Aerial Imagery & Elevation

Statewide, 3 inch, 4 band orthoimagery AND statewide Quality Level 1 lidar (minimum of 14 points per meter, which translates to a 0.5 meter digital elevation model) was collected in the spring of 2023. The project was managed by the CT State GIS Office with the Aerial Imagery Acquisition Workgroup.  See Funding and Project Management below for more information.

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2023 Aerial Imagery



Aerial Imagery Viewer

Once the 2023 imagery is received and published on CT ECO as an image service, it will be added to the Aerial Imagery Viewer, which is an interactive viewer that contains all of Connecticut's statewide, digital aerial imagery.
> Aerial Imagery Viewer Help

CT Geodata Portal

Once the 2023 imagery is received and published on CT ECO as an image service, it will be added to the CT Geodata portal, part of the CT GIS Office, along with the other digital aerial imagery available from CT ECO.

Image Services (Coming in 2024!)

for advanced users
On the Map and Image Services page, look for Imagery-Spring Statewide and then 2023 Spring 4 band, 3 inch. A dynamic service of delivered imagery is currently available. Imagery will be added as it is received. Please note that a dynamic service may take a few seconds to draw. Once the full and final delivery is received, a tiled service will be published.
> Service FAQs

Download (Coming in 2024)

for GIS users
Download will be available by GeoTIFF tile, MrSID Generation 3 tile and MrSID Generation 4 tile. MrSID Generation 3 Town Mosaic and MrSID Generation 4 Town Mosaics will also be available.

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2023 Lidar Elevation



Elevation Viewer

Once the bare earth DEM (digital elevation tiles) are received, they will be published as an image services including elevation, hillshade, shaded relief, slope, aspect and will be part of the Elevation Viewer.
> Elevation Viewer Help

Download (Coming in 2024)

The 2023 DEM, LAS, and contour files will be available for download.

Elevation Image Services (Coming in 2024)

for advanced users
Go to the Map and Image Services page and look for Elevation Layers from 2023.
> Services FAQ



Coming soon!

Funding and Project Management

The 2023/2026 flight project is managed by Alfredo Herrera at the CT State GIS Office with assistance from the Aerial Imagery Acquisition Workgroup's eight members: Erik Snowden, lead (CRCOG), Dan Czaja (DESPP), Stuart Deland (DEEP), Eric Lindquist (DPH), Rich Gallacher (Town of Manchester), Mitch Gugliotti (DOT), and Emily Wilson (UConn). 

The project is funded by the American Rescue Plan with contributions from the CT Department of Transportation and the CT Department of Public Protection and Emergency Services.   



Timeline and Deliverables



  • Statewide, leaf-off, 4-band orthoimagery tiles with 3 inch pixel resolution in GeoTIFF and MrSID formats, tide coordinated
  • True orthoimagery (nadir) over urban center and tall bridges and overpasses
  • Town mosaics in MrSID format


  • Statewide QL1 Lidar point cloud with a minimum of 14 points per square meter with 13 classes, hydro flattened
  • Bare earth 0.5 meter DEM tiles in GeoTIFF format
  • Lidar-derived contours lines (1 and 5 feet)
  • Lidar-derived building footprings for all structures greater than 100 square feet.
  • 3D Terrain Model with 3D buildings


  • FDGC/USGS compliant metadata
  • Reports including data acquisition, survey, production, control and calibration and quality assurance and accuracy


March - April -
Imagery and Lidar acquisition

Visit the CT ECO News blog for updates on data acquisition, delivery, process, and availability. 


May 15 - First delivery of aerials arrives at CLEAR. The delivery included block 1 and block 4, parts 1 and 2.

May 22 - The Ortho 2023 image service of the first delivery is published on CT ECO. Read the First 2023 Aerials Delivery news blog.


Please site the imagery as below. The elevation would be similar - just replace the data layer name.

CT State GIS Office. (2023). 2023 Aerial imagery. Retrieved from https://maps.cteco.uconn.edu/data/flight2023/.  

Image and Elevation Formats

Image Formats

GeoTIFF Highest quality image available here but also the largest file size by a lot.
MrSID Generation 4 Compressed image file that supports all 4 image bands (blue, green, red, near-infrared)
MrSID Generation 3 Compressed image file with the smallest file size because it contains only 3 image bands (blue, green, red)

TIFF or TIF stand for Tagged Image File Format and is used for storing raster images of all kinds. Geo indicates that the TIF has a word file, called TWF that stores geographic information about the raster file.

MrSID stands for MultiresolutionSeamless Image Database. It is a way of compressing imagery so that it can be quickly viewed. LizardTech pioneered the MrSID technology. With each Generation, LizardTech has improved the functions of the MrSID files. MrSID Generation 3 improved upon Generation 2 by supporting unlimited files sizes, lossless encoding with optimization and manipulation options. MrSID Generation 4 improved upon Generation 3 by supporting multi-spectral and hyper-spectral imagery and an improved mechanism for composite mosaicking. Read the full explanation on the LizardTech website.

Elevation Formats

DEM - a raster based (pixel) digital elevation model. The tiles available for download are in Tif format.

LAS - is a lidar data exchange file which is a standard format for airborne lidar point data.

Tiles and Sizes

Delivery Area and Tile Grid

Coming soon!

Tiles and Sizes

Block Number of Tiles File size:
File Size:
File Size:
File Size:
File Size:
Block 1, part 1 2110 1.02 TB 58.9 GB 58.9 GB 78.6 GB
Block 1, part 2 2157 803 GB 60.8 GB 60.8 GB 80.4 GB
Block 1 Total 4267 1.82 TB 119.7 GB 119.7 GB 159 GB
Block 2, part 1
Block 2, part 2
Block 2 Total
Block 3, part 1
Block 3, part 2
Block 3, part 3
Block 3 Total
Block 4, part 1 1467 58.9 GB 40.9 GB 40.9 GB 54.7 GB
Block 4, part 2 1512 563 GB 42.2 GB 42.2 GB 56.3 GB
Block 4, part 3
Block 4, part 4
Block 4, part 5
Block 4 Total

*The GeoTiff file size for each tile in block 1 (520.5 Mb) is greater than the other blocks (390.8 Mb). Block 1 tiles were created with embedded pyramids which was not repeated in other blocks as some software does not recognize them. 

The Facts

23,381 tiles covering Connecticut. Each tile is 2500ft on a side or 0.224 sq miles, 143.5 acres and 6,250,000 sq feet.

The Facts: Imagery

Statewide. 4 bands (red, green, blue, near-infrared).  3 inch pixels.  GeoTIFFs.  MrSIDs Generation 3 and Generation 4. CT State Plane NAD 83 (2011)* Feet. Captured in March and April 2023 (leaf off).  Tide coordinated.

The Facts: Elevation

Statewide. USGS Quality Level 1, minimum of 14 points per sq meter. Minimally ground/non-ground classification. LAS files (point cloud). Bare earth 0.5 m pixel raster tiles (called a Digital Elevation Model or DEM). 1 foot and 5 foot contours derived from Lidar. Captured in March and April 2023 (leaf off).  Tide coordinated.

* NAD 83 (2011) is the most current realization of NAD 83 published by the National Geodetic Survey and is consistent with the national Continuously Operating Reference Stations (CORS) Network.