Ikonos

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Ikonos-2
Mission type Earth observation
Operator DigitalGlobe
Formerly GeoEye, Space Imaging
COSPAR ID 1999-051A
SATCAT № 25919
Mission duration Final: 15 years, 6 months, 6 days
Spacecraft properties
Bus LM-900[1]
Manufacturer Lockheed Martin Space Systems
Launch mass 817 kg (1,801 lb)[1]
Dimensions 1.83 × 1.57 m (6.0 × 5.2 ft)[1]
Power 1,500 W[1]
Start of mission
Launch date 24 September 1999, 18:22 (1999-09-24UTC18:22) UTC[2]
Rocket Athena II, LM-007
Launch site Vandenberg AFB SLC-6
Contractor Lockheed Martin
Entered service December 1999[1]
End of mission
Disposal Decommissioned
Deactivated 31 March 2015 (2015-04-01)[3]
Orbital parameters
Reference system Geocentric
Regime Low Earth
Eccentricity 0.00028
Perigee 678 km (421 mi)
Apogee 682 km (424 mi)
Inclination 98.2°
Period 98.4 minutes
Epoch 24 September 1999, 18:22 UTC[2]
Main telescope
Type Cassegrain[1]
Diameter 70 cm (28 in)[1]
Focal length 10 m (33 ft)[1]
Wavelengths Panchromatic: 450-900 nm[1]
Multispectral: 450-860 nm[1]
Resolution Panchromatic: 0.82–1 m (32–39 in)[1]
Multispectral: 3.2–4 m (130–160 in)[1]

IKONOS is a commercial Earth observation satellite, and was the first to collect publicly available high-resolution imagery at 1- and 4-meter resolution. It offers multispectral (MS) and panchromatic (PAN) imagery. The IKONOS launch was called “one of the most significant developments in the history of the space age”.[4] IKONOS imagery began being sold on 1 January 2000.

It derived its name from the Greek term eikōn for image.[5]

History[edit]

IKONOS was originated under the Lockheed Martin Corporation as the Commercial Remote Sensing System (CRSS) satellite. On April 1994 Lockheed was granted one of the first licenses from the U.S. Department of Commerce for commercial satellite high-resolution imagery. On 25 October 1995 partner company Space Imaging received a license from the Federal Communications Commission (FCC) to transmit telemetry from the satellite in the eight-gigahertz Earth Exploration Satellite Services band. Prior to launch, Space Imaging changed the name of the satellite to IKONOS. IKONOS comes from the Greek word for "image".[5]

Two satellites were originally planned for operation. The launch of IKONOS-1 on 27 April 1999 failed when the payload fairing of the Athena rocket failed to separate, preventing the satellite from reaching orbit. IKONOS-2 was planned for launch in 2000, but was renamed IKONOS and was launched on 24 September 1999 from Space Launch Complex 6 (SLC-6) at Vandenberg Air Force Base in California. The imaging sensors are panchromatic and multispectral. This satellite has a polar, circular, sun-synchronous 681-km orbit and both sensors have a swath width of 11 km. Its weight is 1600 pounds (720 kg).

In November 2000 Lockheed Martin received the "Best of What's New" Grand Award in the Aviation & Space category from Popular Science magazine. Space Imaging was acquired by ORBIMAGE in September 2005. The company was later renamed to GeoEye. GeoEye was acquired in 2013 by DigitalGlobe, which operated IKONOS until its retirement on 31 March 2015.[3]

Specifications[edit]

Spacecraft[edit]

IKONOS is a three-axis stabilized spacecraft designed by Lockheed Martin. The design later became known as the LM900 satellite bus system. The satellite's altitude is measured by two star trackers and a sun sensor and controlled by four reaction wheels; location knowledge is provided by a GPS receiver. The design life is seven years; S/C body size=1.83 m × 1.57 m (hexagonal configuration); S/C mass = 817 kg; power = 1.5 kW provided by three solar panels.

The LM900 spacecraft is a three-axis stabilized bus that is designed to carry scientific payloads in LEOs. It provides precision pointing on an ultra stable highly agile platform. Payloads for a variety of scientific and remote sensing applications may be accommodated including laser sensors, imagers, radar sensors, electro-optical and astronomical sensors, as well as planetary sensors. The LM900 bus shares a hardware heritage with Iridium, which is the basis for the LM700 bus.

Communications[edit]

IKONOS conducts telemetry, tracking and control in the 8345.968–8346.032 MHz band (downlink) and 2025–2110 MHz band (uplink). Downlink data carrier operates in the 8025-8345 MHz band.

Optics & Detectors[edit]

IKONOS has a primary mirror aperture of 0.7 m (2.3 feet), and a folded optical focal length of 10 m (about 33 feet) using 5 mirrors.[6] The main mirror features a honeycomb design to reduce mass.[6] The detectors at the focal plane include a pan-chromatic and a multi-spectral sensor, with 13500 pixels and 3375 pixels respectively (cross-track).[6] Total instrument mass is 171 kg (377 pounds) and it uses 350 watts.[6]

Imaging capabilities[edit]

Spatial resolution[edit]

  • 0.8 m panchromatic (1-m PAN)
  • 4-meter multispectral (4-m MS)
  • 1-meter pan-sharpened (1-m PS)

Spectral Resolution

Band 1-m PAN 4-m MS & 1-m PS
1 (Blue) 0.45–0.90 µm 0.445–0.516 µm
2 (Green) * 0.506–0.595 µm
3 (Red) * 0.632–0.698 µm
4 (Near IR) * 0.757–0.853 µm

Temporal resolution[edit]

The revisit rate for IKONOS is three to five days off-nadir and 144 days for true-nadir.

Radiometric resolution[edit]

The sensor collects data with an 11-bit (0–2047) sensitivity and are delivered in an unsigned 16-bit (0–65535) data format. From time-to-time the data are rescaled down to 8-bit (0–255) to decrease file size. When this occurs much of the sensitivity of the data needed by remote sensing scientists is lost.

Swath[edit]

11 km × 11 km (single scene)

See also[edit]

Notes[edit]

  1. ^ a b c d e f g h i j k l "Ikonos-2". eoPortal. European Space Agency. Retrieved 19 September 2016. 
  2. ^ a b "Launch/Orbital information for Ikonos 2". National Space Science Data Center. NASA. Retrieved 19 September 2016. 
  3. ^ a b "DigitalGlobe's IKONOS Satellite Retired After 15 Years of On-Orbit Operation" (Press release). Lockheed Martin. 14 May 2015. 
  4. ^ Broad, William J. (13 October 1999). "Giant Leap for Private Industry: Spies in Space". The New York Times. Retrieved 23 January 2010. 
  5. ^ a b "Imagery Sources". GeoEye. Retrieved 21 May 2012. 
  6. ^ a b c d Herbert J. Kramer - Observation of the earth and its environment: survey of missions and sensors (2002) - Page 286 (Google Books Link)

References[edit]

External links[edit]