Date of Photography: July 1, 8 & August 12, 2025

Pixel Resolution: 7.5cm

Spectral Bands: RGB Colour & NIR

Airborne Sensor: Vexcel UltraCam Eagle M3 (with 210mm lens)

Coordinate System: 3TM 114W NAD83 (EPSG Code 3776)

Date Orthophoto Created: 2025

Data Steward Contact: Geospatial Business Solutions division, GBS@Calgary.ca

Horizontal Accuracy :+/-15cm at 95% confidence level on flat ground surfaces. (confirmed with 70+ surveyed ground control points in the original 3TM 114W NAD83 version.)

The orthophoto is a seamless mosaic of accurately positioned aerial images. These aerial images are geometrically corrected for camera perspective and terrain relief so that they have a consistent scale and can be used for direct positional measurements of ground features like a map.

The aerial photo was captured using a fixed wing aircraft equipped with a special aerial camera sensor and high accuracy GNSS/INS positioning systems to gather thousands of overlapping images in a grid pattern across the entire city. These stereo images were accurately geo-referenced and tied together using the airborne and ground control data in a photogrammetric aerial triangulation. The imagery was then orthorectified using the Calgary 2022-2024 LIDAR bare-earth DEM.

Orthophoto is considered a core geospatial dataset. It is commonly used in many applications such as geospatial analysis, engineering design, City planning, asset management and as a base GIS dataset providing rich contextual information for anywhere in the city. The Calgary orthophoto is updated annually with a city-wide aerial survey flown each spring.