ground stations. The images are reconstructed from the data received at the ground stations. The National Remote Sensing Centre is responsible for acquisition, processing of data relayed by the Cartosat-1. A spherical Phased Array Antenna with steerable beam is used to transmit the data to the required ground station. A solid state recorder with 120 Gb capacity to store about 9 minutes of payload data is available for global operation of the payloads. The stored images can be transmitted when the satellite comes within the visibility zone of a ground station. Optics and detectors Each Panchromatic camera consists of three 3 mirror off-axis all reflective telescope with primary, secondary and tertiary mirrors. These mirrors are made from special zerodur glass blanks and are light weighted to about 60%. These mirrors are polished to an accuracy of l/80 and are coated with enhanced aluminium oxide (AlO2) coating. In order to meet the high resolution and the swath requirement a 12K, 7 µm linear array charge-coupled device (CCD) is used as a detector. Imaging capabilities Spatial resolution 2.5 m panchromatic band (0.5-0.85 µm) Temporal resolution The revisit rate for Cartosat-1 is five days. Radiometric resolution The sensor collects data with a 10-bit sensitivity. Swath 30 km (PAN-F) and 25 km (PAN-A) See also List of Indian satellites References External links Cartosat-1 website Cartosat Spacecraft launched in 2005 Spacecraft launched by PSLV rockets