None known

DigitalGlobe

Worldview-1 was one of the first sub-meter resolution commercial satellites. Launched in 2007, Worldview-1 provides 50-cm resolution panchromatic imagery. Because of the agility of the satellite to reposition the satellite (i.e., angle the sensor at off-nadir angles), Worldivew-1 has a revisit time (i.e., can image the same place on the earth) of less than two days.

• Ikonos - panchromatic sensor
• Quickbird - panchromatic sensor
• Worldview 2 - panchromatic sensor
• GeoEye-1 - panchromatic sensor

Worldview-1 is a single panchromatic sensor that was launched in September 2007

Worldview-1 has a single panchromatic band that captures reflected electromagnetic radiation between 0.4 and 0.9 μm. Imagery is recorded with a 11-bit radiometric depth.

The swath width of Worldview-1 is 17.6 km at nadir.

Image resolution of Worldview-1 imagery depends on the off-nadir angle at which it is collected. At nadir, Worldview-1 imagery has a ground resolution of 0.5m (50cm). At a 25-degree off-nadir angle, it has a resolution of 0.59m. The sensor is capable of looking as much as 45 degrees off nadir, however. At these extreme off-nadir angles, ground resolution will be greater than 1m.

Return interval also depends on off-nadir viewing angle. At a 25-degree off-nadir angle, revisit time is 4.6 days. At maximum off-nadir angle (+/- 45 degrees), revisit time is 1.7 days.

There are costs associated with Worldview-1 imagery. Products can be purchased directly from DigitaGlobe or one of its many resellers. Use this link to explore both options: http://www.digitalglobe.com/index.php/22/How+to+Purchase

Products from DigitalGlobe come in three processing levels:

• Basic – Only radiometric distortions and internal sensor adjustments have been made to the data. Products are ordered by the scene (16.5 km x 16.5 km).
• Standard –Georectified and delivered in map projection. Area based ordering, meaning you have to specify your area of interest.
• Orthorectified – GIS ready with geometric and topographic correction, and delivered with a map projection. Area based ordering, meaning you have to specify your area of interest.

See http://www.digitalglobe.com/index.php/22/How+to+Purchase for current pricing and licensing options.

From DigitalGlobe, Worldview-1 imagery can be obtained in a Geotiff format making it user friendly for geographic information systems such as ArcGIS and common image processing software. Alternatively, images can be in NITF 2.1 or NITF 2.0, a format primarily used by the intelligence and military communities.

None known at this time.

Quickbird 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. Geotiff images often come as one band per file. For the purposes of making it easier to handle, manipulate, and display the imagery, most people combine all of the separate image bands into a single, multi-band image file using an image-processing package. The size of the files will depend on the extent of the scene, but because of its fine resolution Quickbird data can be very large (1 GB or more).

• DigitalGlobe Worldview-1 page - http://www.digitalglobe.com/index.php/86/WorldView-1

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