The Tracking & Imaging Radar (TIRA) system serves as the central experimental facility for the development and investigation of

radar Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ...

techniques for the detection and reconnaissance of objects in space, and (to a certain degree) of air targets. TIRA is located at the FGAN () site, in

Wachtberg Wachtberg is a municipality in the Rhein-Sieg district, of North Rhine-Westphalia, Germany. It is situated approximately 15 km south of Bonn Bonn () is a federal city in the German state of North Rhine-Westphalia, located on the banks o ...

near

Bonn Bonn () is a federal city in the German state of North Rhine-Westphalia, located on the banks of the Rhine. With a population exceeding 300,000, it lies about south-southeast of Cologne, in the southernmost part of the Rhine-Ruhr region. This ...

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

. It is run by the

Fraunhofer-Gesellschaft The Fraunhofer Society () is a German publicly-owned research organization with 76institutes spread throughout Germany, each focusing on different fields of applied science (as opposed to the Max Planck Society, which works primarily on basic sc ...

-FHR – the Fraunhofer-Institut für Hochfrequenzphysik und Radartechnik (High Frequency Physics and Radar Techniques), part of the German

Fraunhofer Society The Fraunhofer Society () is a German publicly-owned research organization with 76institutes spread throughout Germany, each focusing on different fields of applied science (as opposed to the Max Planck Society, which works primarily on Basic re ...

. TIRA has a 34-metre

parabolic dish antenna A parabolic antenna is an antenna that uses a parabolic reflector, a curved surface with the cross-sectional shape of a parabola, to direct the radio waves. The most common form is shaped like a dish and is popularly called a dish antenna or pa ...

is a

monopulse radar Monopulse radar is a radar system that uses additional encoding of the radio signal to provide accurate directional information. The name refers to its ability to extract range and direction from a single signal pulse. Monopulse radar avoids prob ...

operating at 1.333 GHz or 22.5 cm (

L band The L band is the Institute of Electrical and Electronics Engineers (IEEE) designation for the range of frequencies in the radio spectrum from 1 to 2 gigahertz (GHz). This is at the top end of the ultra high frequency (UHF) band, at the lower en ...

) and 16.7 GHz or 1.8 cm (

Ku band The Ku band () is the portion of the electromagnetic spectrum in the microwave range of frequencies from 12 to 18 gigahertz (GHz). The symbol is short for "K-under" (originally ), because it is the lower part of the original NATO K ban ...

)

wavelength In physics and mathematics, wavelength or spatial period of a wave or periodic function is the distance over which the wave's shape repeats. In other words, it is the distance between consecutive corresponding points of the same ''phase (waves ...

s. The L-band is usually used for tracking debris with a 0.45° beam width, at 1 MW peak power. The system is capable of determining

orbit In celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an ...

s from direction angles, range and

Doppler shift The Doppler effect (also Doppler shift) is the change in the frequency of a wave in relation to an observer who is moving relative to the source of the wave. The ''Doppler effect'' is named after the physicist Christian Doppler, who described t ...

for single targets. The detection size threshold is about 2 cm at 1000 km range. The radar conducts regular ‘beam park’ experiments, where the radar beam is pointed in a fixed direction on the

celestial sphere In astronomy and navigation, the celestial sphere is an abstract sphere that has an arbitrarily large radius and is concentric to Earth. All objects in the sky can be conceived as being projected upon the inner surface of the celestial sphere, ...

for 24 hours, scanning 360° in a narrow strip a complete Earth rotation. The tracking sensitive can be enhanced when the TIRA system is used as a transmitter, part of a

bistatic radar Bistatic radar is a radar system comprising a transmitter and receiver that are separated by a distance comparable to the expected target distance. Conversely, a conventional radar in which the transmitter and receiver are co-located is called ...

system. In conjunction with the Effelsberg Radio Telescope, functioning as a receiver, the combined system has a detection size threshold of 1 cm. The Ku-band is used for

imaging Imaging is the representation or reproduction of an object's form; especially a visual representation (i.e., the formation of an image). Imaging technology is the application of materials and methods to create, preserve, or duplicate images. ...

Inverse Synthetic Aperture Radar Inverse synthetic-aperture radar (ISAR) is a radar technique using radar imaging to generate a two-dimensional high resolution image of a target. It is analogous to conventional SAR, except that ISAR technology uses the movement of the target rat ...

(ISAR) mode, with 13 kW peak power, the radar is capable of producing images with range resolutions better than 7 cm. The dish can be turned full 360° in

azimuth An azimuth (; from ) is the horizontal angle from a cardinal direction, most commonly north, in a local or observer-centric spherical coordinate system. Mathematically, the relative position vector from an observer ( origin) to a point ...

with speed of 24° per second and 90° in

elevation The elevation of a geographic location (geography), ''location'' is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational equipotenti ...

. The radar is protected by a

radome A radome (a portmanteau of "radar" and "dome") is a structural, weatherproof enclosure that protects a radar antenna (radio), antenna. The radome is constructed of material transparent to radio waves. Radomes protect the antenna from weathe ...

with 47 meters diameter – one of the largest in the world. Due to its capabilities, the system is used as a radar tracking system for

space debris Space debris (also known as space junk, space pollution, space waste, space trash, space garbage, or cosmic debris) are defunct human-made objects in spaceprincipally in Earth orbitwhich no longer serve a useful function. These include dere ...

and other in-orbit object in the

ESA The European Space Agency (ESA) is a 23-member international organization devoted to space exploration. With its headquarters in Paris and a staff of around 2,547 people globally as of 2023, ESA was founded in 1975 in the context of European ...

Space Situational Awareness Programme The Space Safety Programme, formerly the Space Situational Awareness (SSA) programme, is the European Space Agency's (ESA) initiative to monitor hazards from space, determine their risk, make this data available to the appropriate authorities and w ...

(SSA).{{cite web, url = http://www.esa.int/Our_Activities/Operations/Space_Situational_Awareness/Space_Surveillance_and_Tracking_-_SST_Segment, title=Europe’s Radar Space Surveillance and Tracking Sensors, access-date=2015-05-03, publisher=ESA

External links

Space observation radar TIRA

References

Radar networks Space Situational Awareness Programme Research and development in Germany