The highest spatial
resolution of optical imageries from commercial satellites is up to 60–70 centimetres
(QuickBird owned by DigitalGlobe, Inc.) or 1 metre (IKONOS operated by GeoEye). Since
the 2004 Sumatra-Andaman earthquake tsunami, these satellites have captured images of
tsunami-affected areas, and the images have been used for disaster management activities,
including emergency response and recovery.