Ikonos

IKONOS

IKONOS 2
Organization	GeoEye
Mission Type	Earth observation
Contractor	Lockheed Martin Space Systems
Satellite of	Earth
Launch	September 24, 1999 on an Athena 2
Launch site	Vandenberg Air Force Base
Mission duration	Ongoing
Mass	726 kg (launch)
Webpage	http://www.geoeye.com/CorpSite/products/imagery-sources/Default.aspx#ikonos
Orbital elements
Semi-major axis	7056.97 km
Eccentricity	0.00013
Inclination	98.10 degrees
Orbital Period	98.33 minutes
Right ascension of the ascending node	68.015 degrees
Argument of perigee	93.06 degrees
Instruments
Visible Sensors	1-meter panchromatic and 4-meter multispectral

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”. IKONOS imagery began being sold on January 1, 2000.

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

History

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 October 25, 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".

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 April 2015 when the spacecraft was deactivated.

Specifications

Spacecraft

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

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

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. The main mirror features a honeycomb design to reduce mass. The detectors at the focal plane include a pan-chromatic and a multi-spectral sensor, with 13500 pixels and 3375 pixels respectively (cross-track). Total instrument mass is 171 kg (377 pounds) and it uses 350 watts.

Imaging capabilities

Spatial resolution

• 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

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

Radiometric resolution

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

11 km × 11 km (single scene)

See also

• GeoEye-1

References

• Annual Selection of Spectacular Satellite Images to be Determined by Public Voting Thursday, 23 December 2004
• Sensor Specifications: Ikonos NASA

External links

• IKONOS page on the Geo-Eye website
• Private Eyes, a New York Times Magazine feature in anticipation of IKONOS launch