Post by syzygy on Jul 19, 2016 13:33:59 GMT
However leading news sources call it the largest, the newly built Chinese FAST is only the second largest radiotelescope after the Russian RATAN-600.
It is just natural, Russians have preceded everyone again (by 42 years and 110 meters).(:
To be exact it is not the largest radiotelescope, but the largest spherical (to be more appropriate 'parabolic) radiotelescope after the old (completed in 1963) and widely known Arecibo Observatory.
(Xinhua/Ou Dongqu)
source: news.xinhuanet.com
The Five-hundred-meter Aperture Spherical Telescope (FAST) (nicknamed Tianyan "Heavenly Eye" or "The Eye of Heaven"), is a radio telescope located in the Dawodang depression, a natural basin in Pingtang County, Guizhou Province, southwest China.
Construction on the FAST project began in 2011 and has been completed in July 2016. It is expected to be operational by September 2016. It will be the world's second largest radio telescope (after the Russian RATAN-600, which has a sparsely filled aperture). Originally budgeted for CN¥700 million, the final price was CN¥1.2 billion (US$180 million).
The telescope was first proposed in 1994. The project was approved by the National Development and Reform Commission (NDRC) in July 2007. A 65-person village was relocated from the valley to make room for the telescope and an additional 9,110 people living within a 5 km radius of the telescope were relocated to create a radio-quiet area.
On December 26, 2008, a foundation laying ceremony was held on the construction site. Construction started in March 2011, and the last panel was installed on the morning of 3 July 2016.
FAST has a fixed primary reflector located in a natural hollow (karst), focusing radio waves on a receiver suspended 140 m (460 ft) above it. The reflector is made of perforated aluminum panels supported by a mesh of steel cables hanging from the rim.
FAST's surface is made of 4450 triangular panels, 11 m (36 ft) on a side, in the form of a geodesic dome. Actuators underneath make it an active surface, pulling and pushing on joints between panels, deforming the flexible steel cable support into a parabolic antenna aligned with the desired sky direction.
Above the reflector is a light-weight feed cabin moved by a cable robot using winch servomechanisms on six support towers. The receiving antennas are mounted below this on a Stewart platform which provides fine position control and compensates for disturbances like wind motion. This produces a planned pointing precision of 8 arcseconds.
FAST is capable of pointing anywhere within ±40° from the zenith. The effective aperture is reduced by vignetting at angles above ±30°.
Although the reflector diameter is 500 metres (1,600 ft), only a circle of 300 m diameter is used (held in the correct parabolic shape and "illuminated" by the receiver) at any one time. Thus, the name is a misnomer: the aperture is not 500 m, nor is it spherical.
Its working frequency range of 70 MHz to 3.0 GHz, is covered by 9 receivers, with the 1.23–1.53 GHz band around the hydrogen line using a 19-beam receiver built by the CSIRO as part of the ACAMAR collaboration between the Australian Academy of Science and the Chinese Academy of Sciences.
wikipedia
At first I wanted only mark the FAST as it has been finished recently, but realized that there is even no placemark* by RATAN so attached a file for it too.
*EDIT: oops! have not made a search here on the nGEC so missed ET's posting about RATAN-600. Sorry ET! File removed.
best,
g
FAST.kmz (896 B)
It is just natural, Russians have preceded everyone again (by 42 years and 110 meters).(:
To be exact it is not the largest radiotelescope, but the largest spherical (to be more appropriate 'parabolic) radiotelescope after the old (completed in 1963) and widely known Arecibo Observatory.
(Xinhua/Ou Dongqu)
source: news.xinhuanet.com
The Five-hundred-meter Aperture Spherical Telescope (FAST) (nicknamed Tianyan "Heavenly Eye" or "The Eye of Heaven"), is a radio telescope located in the Dawodang depression, a natural basin in Pingtang County, Guizhou Province, southwest China.
Construction on the FAST project began in 2011 and has been completed in July 2016. It is expected to be operational by September 2016. It will be the world's second largest radio telescope (after the Russian RATAN-600, which has a sparsely filled aperture). Originally budgeted for CN¥700 million, the final price was CN¥1.2 billion (US$180 million).
The telescope was first proposed in 1994. The project was approved by the National Development and Reform Commission (NDRC) in July 2007. A 65-person village was relocated from the valley to make room for the telescope and an additional 9,110 people living within a 5 km radius of the telescope were relocated to create a radio-quiet area.
On December 26, 2008, a foundation laying ceremony was held on the construction site. Construction started in March 2011, and the last panel was installed on the morning of 3 July 2016.
FAST has a fixed primary reflector located in a natural hollow (karst), focusing radio waves on a receiver suspended 140 m (460 ft) above it. The reflector is made of perforated aluminum panels supported by a mesh of steel cables hanging from the rim.
FAST's surface is made of 4450 triangular panels, 11 m (36 ft) on a side, in the form of a geodesic dome. Actuators underneath make it an active surface, pulling and pushing on joints between panels, deforming the flexible steel cable support into a parabolic antenna aligned with the desired sky direction.
Above the reflector is a light-weight feed cabin moved by a cable robot using winch servomechanisms on six support towers. The receiving antennas are mounted below this on a Stewart platform which provides fine position control and compensates for disturbances like wind motion. This produces a planned pointing precision of 8 arcseconds.
FAST is capable of pointing anywhere within ±40° from the zenith. The effective aperture is reduced by vignetting at angles above ±30°.
Although the reflector diameter is 500 metres (1,600 ft), only a circle of 300 m diameter is used (held in the correct parabolic shape and "illuminated" by the receiver) at any one time. Thus, the name is a misnomer: the aperture is not 500 m, nor is it spherical.
Its working frequency range of 70 MHz to 3.0 GHz, is covered by 9 receivers, with the 1.23–1.53 GHz band around the hydrogen line using a 19-beam receiver built by the CSIRO as part of the ACAMAR collaboration between the Australian Academy of Science and the Chinese Academy of Sciences.
wikipedia
At first I wanted only mark the FAST as it has been finished recently, but realized that there is even no placemark* by RATAN so attached a file for it too.
*EDIT: oops! have not made a search here on the nGEC so missed ET's posting about RATAN-600. Sorry ET! File removed.
best,
g
FAST.kmz (896 B)
