Written by Jeffrey Gillan
Agency/Company Operating the Sensor
IKONOS is commercially operated by GeoEye (formerly called Space Imaging)
IKONOS is a spaceborne multispectral sensor with very high spatial resolution capabilities. Launched in 1999, it was the first commercial satellite with sub-meter resolution in a panchromatic band. It also has 4 color bands with 4 meter resolution (blue, green, red, near infrared). The sensor has the ability to rotate and can acquire images up to 60 degrees off nadir.
IKONOS data is very useful for studying surface conditions on a fine scale. Its short return interval (3 days) is also advantageous for observing changing conditions and increases the chance of getting cloud and smoke free scenes. Unlike sensors such as Landsat and MODIS which are continually acquiring and archiving data, IKONOS imagery is gathered on-demand. One potential drawback of using IKONOS data is the cost of acquiring the imagery, though archived data may be available at reduced costs.
The panchromatic band has a spatial resolution of .82 meters at nadir. The 4 color bands have a spatial resolution of 4 meters at nadir. Images acquired at off-nadir angles will have spatial resolutions greater than what is listed above. Ikonos data are gathered in 11-bit radiometric precision (pixels can have values from 0 to 2,047) but can also be scaled down to 8-bits (0-256).
Image footprint or swath width
Swath width for Ikonos is 11.3 km at nadir. Scene sizes are customizable, and you pay for only the imagery within your study area. For large areas, multiple passes may be required. Thus, several smaller images will need to be combined to get a seamless image for the larger area.
Ikonos is in a sun synchronous orbit above the Earth. With the ability to position the camera at off-nadir angles, Ikonos can re-image a place on Earth approximately every 3 days. If extreme off-nadir angles are not acceptable, then revisit times increase.
1999 to present
Cost, Acquisition, Licensing
All information regarding IKONOS products is available on the GeoEye website. http://www.geoeye.com/CorpSite/
From GeoEye you can get georeferenced (Geo) images, orthorectified (terrain corrected, Geo Professional) images, and stereo images (Geo Stereo). Scene sizes can be customized to fit your area of interest. Image costs are $10 per km2 for archived images, and $20 per km2 for new acquisitions. Images can be retrieved through an FTP site or mailed.
Products can also be purchased through many of GeoEye’s channel partners. Some of the companies sell higher processed products and some of the companies might sell images at reduced costs. A list of resellers can be found here. http://www.geoeye.com/CorpSite/Products/channel-partners/Default.aspx
Because IKONOS is commercially operated, there are some licensing restrictions regarding image usage and sharing. Please consult with GeoEye to get the level of licensing that is appropriate for your research or project.
IKONOS imagery is primarily distributed in a Geotiff format making it user friendly for geographic information systems such as ArcGIS and common image processing software.
Examples of Rangeland Uses
- Sidle et al (2002) used 1 meter resolution IKONOS imagery to identify black-tailed prairie dog colony locations without any classification algorithms.
- Lawrence et al (2006) used multi-temporal IKONOS images to classify prairie pothole communities in North Dakota.
- Ludwig et al (2004) used high resolution IKONOS imagery to help assess rangeland functional integrity indicators in Australia.
- Karl and Maurer (in press) found that Ikonos imagery performed better than Landsat imagery with object-based image analysis for predicting rangeland attributes in Craters of the Moon National Monument, Idaho.
IKONOS images usually come in a user friendly Geotiff format, which is preferred because of its easy integration with GIS platforms like ArcGIS and image processing programs such as Erdas Imagine and ENVI. The size of the files will depend on the extent of the scene, but because of its fine resolution, IKONOS data can be very large (1 GB or more).
- Jenson, John R. (2007), Remote Sensing of the Environment: An Earth resource perspective, second edition, Prentice Hall series in geographic information science, Upper Saddle River, NJ.
- Karl, J.W. and B.A. Maurer. In press. Multivariate correlations between imagery and field measurements across scales: comparing pixel aggregation and image segmentation. Landscape Ecology.
- Lawrence, R., R. H. T. Weaver, and R. Aspinall (2006), Mapping prairie pothole communities with multi-temporal IKONOS satellite imagery, Photogrammetric Engineering & Remote Sensing, Vol. 72, No. 2, pp. 169-174.
- Ludwig, J. A., D. J. Tongway, G. N. Baston, and C. D. James (2004), Monitoring ecological indicators of rangeland functional integrity and their relation to biodiversity at local to regional scales, Austral Ecology, Vol. 29, pp. 108-120.
- Sidle, J. G., D. H. Johnson, B. R. Euliss, and M. Tooze (2002), Monitoring black-tailed praire dog colonies with high-resolution satellite imagery, Wildlife Society Bulletin, Vol. 30, No. 2, pp. 405-411.