Satellite Imagery Resolution Comparison
To illustrate differences in resolution, LAND INFO has posted images of the same area (an airport surrounded by varying land uses) from several different satellite sensors (as well as a scan of a traditional air photo):
- Landsat 7 30m resolution
- Landsat 7 15m resolution
- Spot 20m resolution
- Spot 10m resolution
- IRS 1C 5m
- Radarsat 12.5m resolution
- ERS 12.5m resolution
- 1:60,000 aerial photo scanned at 300 dpi
In analyzing the different data types, it’s important to keep the end application in mind. For instance the Landsat 7 15m data is not as sharp as either the Spot 10m or IRS-1C 5m data, but the amount of information it contains along with its large area coverage and low price still make it suitable for a number of general-use applications or small-scale mapping projects.
Graphics courtesy of Dr. Philip Cheng, Dr. Thierry Toutin, and Dr. Victor Tom, authors of “Unlocking the Potential for Landsat 7 Data,” and PCI Geomatics.
Landsat 7 30m resolution
Landsat 7 15m resolution
Spot 20m resolution
Spot 10m resolution
IRS 1C 5m
Radarsat 12.5m resolution
ERS 12.5m resolution
1:60,000 aerial photo scanned at 300 dpi
Object Based Image Analysis will reduce costs and speed turn-around on your next land-use/land-cover, vegetation, impervious surface or change detection mapping project.
Vector Feature Extraction: accurate extraction of layers such as buildings, hydrology, transportation and other infrastructure.