Statewide, 3 inch, 4 band orthoimagery AND statewide Quality Level 2 lidar (which translates to a 1 meter digital elevation model) were collected in the spring of 2016 marking the first time that Connecticut has captured imagery and elevation at such a high level of detail. The project was managed by the Capitol Region Council of Governments (CRCOG), on behalf of all nine regional councils of governments, and funded by the Connecticut Office of Policy and Management (OPM) with contributions from the Connecticut Department of Transportation (DOT) and the Connecticut Department of Emergency Services and Public Protection (DESPP).
2016 Aerial Imagery
2016 Lidar Elevation
for GIS users
Download 2016 bare earth DEM and LAS tiles on CT ECO. Download selected area with advanced options from the NOAA Data Access Viewer. Look for 2016 CRCOG Lidar.
> Download Help
> Lidar FAQs
for GIS users
Download 2016 contour files.
- the 2016 aerial imagery
- 2016 lidar DEM
- 2016 LAS file metadata is included with each tile in the download
- 2016 contours
2016 Aerial Imagery Metadata Correction
The current version contains several corrections. The imagery tiles available for download contain the older version of the metadata file. Please note these corrections.
A correction was made in the Description, Purpose section. The correct information is:
Purpose: Rectified orthoimagery is for public use.
A correction was made in the Data Access Constraints section. The correct information is:
Access constraints: None. This data is in the public domain.
Use constraints: None. Users can copy, modify, distribute and perform work, even for commercial purposes, without requesting permission.
A correction as in the Metadata, Metadata Access Constraints section. The correct information is:
Access constraints: None. This data is in the public domain.
Use constraints: None. Users can copy, modify, distribute and perform work, even for commercial purposes, all without requesting permission.
Funding and Project Management
In December 2014, the Capitol Region Council of Governments (CRCOG), on behalf of all nine regional councils of governments, submitted a grant application to the Office of Policy and Management (OPM) to fund the acquisition of high quality aerial imagery and Lidar through the Regional Performance Incentive Program. This unique funding strategy arose from OPM’s recognition of the need to improve the inefficient and uncoordinated practice of funding imagery acquisitions at regional scales in prior years. In addition, OPM saw opportunity to leverage funding from the Departments of Transportation (DOT) and Emergency Services and Public Protection (DESPP), who were planning to jointly purchase lower quality statewide imagery (12-inch pixel resolution) in the absence of any broader statewide coordination. A much sharper 3-inch pixel resolution was proposed for CRCOG’s base deliverable in order to satisfy the needs of all users and avoid duplicative acquisitions by entities who require high-resolution imagery.
CRCOG’s grant application, led by project manager Erik Snowden, was awarded by OPM in 2015, with funding contributions from DOT and DESPP. Shortly thereafter, CRCOG released a request for proposals and began the selection process, working with a small team of talented individuals to procure a vendor and finalize a contract. Sanborn Map Company was selected as the vendor for this project.
These folks were instrumental in getting the funds together and making the acquisition happen. Thanks to Erik Snowden (CRCOG), Eric Lindquist (OPM), Mark Goetz (MetroCOG), Emily Wilson (UConn), Carl Zimmerman (WestCOG), Bob Baron (DOT), Dan Czaja (DESPP) and Rich Gallacher (Town of Manchester).
Timeline and Deliverables
The flight was planned roughly for late March and April, between snow melt and leaf off. For imagery acquisition, Sanborn deployed multiple aircraft on clear days to collect imagery during hours of high sun angle to minimize shadows. Along the coast, the aircraft flew during low tide. Lidar acquisition does not use sunlight, so planes collecting Lidar were deployed at any hour.
After data capture, there was extensive data processing and quality control analysis. All data was delivered to CRCOG by the end of 2016. At that time, CT ECO processed the files for serving and distribution. The imagery and bare earth DEM are available as image services and for download.
- Statewide, 4-band orthoimagery tiles with 3 inch pixel resolution in GeoTIFF and MrSID formats
- Town mosaics in MrSID format
- Statewide QL2 Lidar point cloud as LAS files with ground/non-ground classification and hydro flattened
- Bare earth 1 meter DEM tiles in GeoTIFF format
- Contours lines (1 and 5 feet)
- Hydro break lines
- Intensity images in GeoTIFF format
- FDGC/USGS compliant metadata
- Reports including data acquisition, survey, production, control and calibration and quality assurance and accuracy
March 11 - Flying begins for both Lidar and imagery
April 18 - Imagery and Lidar collection completed
March 7 – Tile delivery grid finalized
May - Pilot imagery tiles received by CRCOG
June - QA/QC Firm selected to do independent review
June – Pilot lidar tiles received by CRCOG
November – Decision made to get two types of MrSID (generation 3 and generation 4) to meet needs or all users
December - Imagery tiles for blocks 1, 3, 5, 7 (western half of the state) approved by QA/QC process
December 29 – UConn receives Blocks 1, 3, 5, 7 imagery tiles and begins processing
January – Imagery tiles for blocks 2, 4 (eastern half, south and central) approved by QA/QC process
January 24 – Imagery tiles for blocks 2, 4 (eastern half, south and central) received by UConn
February 10 - all imagery approved by QA/QC process
February 13 - Imagery tiles for block 6, the last one, (northeast) received by UConn
February 22 - dynamic map service and tiled map service completed for the state. All tiles available for download.
March 27 - town mosaics arrive at CLEAR
April 3 - town mosaics available for download
May 22 - lidar DEM metadata and DEM tiles for blocks 3, 5, 7 arrived at CLEAR
May 23 - lidar DEM tiles for blocks 3, 5 and 7 available for download
June 23 - lidar DEM metadata and DEM tiles for blocks 1, 2 and 4 arrived at CLEAR
June 27 - lidar DEM tiles for blocks 1, 2 and 4 available for download
July 14 - lidar DEM tiles for block 6 arrive and available for download. That's the last of the DEMs!
July 25 - All LAS files arrive at CLEAR
Aug 11 - DEM images services up
Sept 1 - Final LAS metadata available
Sept 18 - LAS files available for download
Sept 19 - Contour tiles arrive at CLEAR
Please site the imagery as below. The elevation would be similar - just replace the data layer name.
Capitol Region Council of Governments. (2016). 2016 Aerial imagery. Retrieved from http://cteco.uconn.edu/data/flight2016/index.htm.
Image and Elevation 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.
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
- View the area in a pdf of a map
- Download the area covered in GIS shapefile format
- Download the tile grid in GIS shapefile format
- Download the delivery blocks in GIS shapefile format
Tiles and Sizes
|Block||Number of Tiles||File size: GeoTIFF||File Size: MrSID Gen 3||File Size: MrSID Gen 4||File Size: DEM||File Size: LAS||File Size: Contours|
|1||3881||1.41 TB||54.2 GB||72.4 GB||23.0 GB||302 GB||16.9 GB|
|2||4169||1.51 TB||58.2 GB||77.7 GB||25.2 GB||299 GB||18.9 GB|
|3||3239||1.15 TB||45.2 GB||60.4 GB||19.8 GB||239 GB||16.7 GB|
|4||3200||1.16 TB||44.7 GB||59.6 GB||19.4 GB||230 GB||14.1 GB|
|5||3061||1.11 TB||42.8 GB||57.0 GB||18.7 GB||234 GB||19.4 GB|
|6||3617||1.31 TB||50.5 GB||67.4 GB||21.0 GB||317 GB||16.4 GB|
|7||2214||825 GB||30.9 GB||41.2 GB||13.5 GB||199 GB||15.4 GB|
|TOTAL||23,381||8.48 TB||326.5 GB||435.7 GB||140.6 GB||1.82 TB||117.8 GB|
|169||-||631 GB||869 GB|
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. 8.5 TB of GeoTIFFs and 763 GB of MrSIDs (Generation 3 is 327 GB and Generation 4 is 436 GB). Captured in March and April 2016 (leaf off). Tide coordinated.
The Facts: Elevation
Statewide. USGS Quality Level 2. 2 points per sq meter. Ground/non-ground classification. LAS files (point cloud). Bare earth 1m pixel raster tiles (called a Digital Elevation Model or DEM). 1 foot and 5 foot contours derived from Lidar. Intensity images. Captured in March and April 2016 (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.