Define QuickBird and IKONOS.

QuickBird:

QuickBird is a high-resolution Earth observation satellite that was part of the DigitalGlobe constellation. Launched on October 18, 2001, QuickBird was known for its advanced imaging capabilities, providing very high spatial resolution imagery for a variety of applications. Some key features of QuickBird include:

1. Spatial Resolution: QuickBird was equipped with a panchromatic sensor capable of capturing imagery with a spatial resolution of 61 centimeters (cm). This high spatial resolution allowed for detailed mapping and analysis of urban areas, infrastructure, and natural landscapes.

2. Multispectral Imaging: In addition to the panchromatic sensor, QuickBird had a multispectral sensor with a spatial resolution of 2.44 meters. The multispectral bands included blue, green, red, and near-infrared, enabling the satellite to capture imagery in different parts of the electromagnetic spectrum.

3. Applications: QuickBird's high-resolution imagery found applications in urban planning, environmental monitoring, disaster response, agriculture, and defense. The detailed and accurate imagery supported various industries and government agencies in making informed decisions.

4. Orbit: QuickBird operated in a sun-synchronous orbit, ensuring consistent lighting conditions across its imaging swaths during its passes over the Earth's surface.

IKONOS:

IKONOS was one of the pioneering commercial Earth observation satellites and the first to provide high-resolution satellite imagery to the public. Launched on September 24, 1999, by Space Imaging, IKONOS played a crucial role in advancing the field of commercial satellite imagery. Key characteristics of IKONOS include:

1. Spatial Resolution: IKONOS was renowned for its high spatial resolution, capturing panchromatic imagery with a resolution of 0.82 meters. This level of detail allowed for the identification of small objects and features on the Earth's surface.

2. Multispectral Imaging: The satellite featured a multispectral sensor with a spatial resolution of 3.2 meters. The multispectral bands included blue, green, red, and near-infrared, providing valuable information for land cover classification and environmental monitoring.

3. Applications: IKONOS imagery found applications in urban planning, agriculture, forestry, disaster management, and defense. The high-resolution and multispectral capabilities made it a valuable asset for a wide range of industries and government agencies.

4. Orbit: Similar to QuickBird, IKONOS operated in a sun-synchronous orbit, ensuring consistent lighting conditions and facilitating accurate and repeatable observations.

Both QuickBird and IKONOS significantly contributed to the commercial Earth observation market by providing high-quality satellite imagery for various applications. While they have been succeeded by newer satellite systems with even higher resolutions, their role in advancing remote sensing technologies and applications remains noteworthy.