2 ms·

Does it seem like this would replace or improve upon what was lost at Arecibo?

shagie 4y ago
From the page on the test - https://greenbankobservatory.org/successful-test-paves-way-for-new-planetary-radar/ https://greenbankobservatory.org/successful-test-paves-way-f... > Using the information collected with this latest test, the participants will finalize a plan to develop a 500-kilowatt, high-power radar system that can image objects in the Solar System with unprecedented detail and sensitivity. The increased performance also will allow astronomers to use radar signals as far away as the orbits of Uranus and Neptune, increasing our understanding of the Solar System. > “The planned system will be a leap forward in radar science, allowing access to never before seen features of the Solar System from right here on Earth,” said Karen O’Neil, the Green Bank Observatory site director. That use of the word "unprecedented" and looking at Uranus and Neptune suggests to me that it will go further than Arecibo did... three decades ago. https://ui.adsabs.harvard.edu/abs/2000DDA....31.0803N/abstract https://ui.adsabs.harvard.edu/abs/2000DDA....31.0803N/abstra... > In October 1999 we obtained the first radar images of Saturn's rings, using the recently-upgraded Arecibo telescope operating at a wavelength of 12.6 cm. The opening angle of the rings was 19.9o, and dual-circular polarization data were collected over a period of 5 days. The resulting delay-Doppler maps have a range resolution of 100 msec and a frequency resolution of 2 kHz, corresponding to a spatial resolution cell of 15000 x 2000 km. Previous radar observations (e.g., Ostro et al. [1982] Icarus 49, 367) demonstrated the rings' high cross section and depolarization ratio, but did not yield 2-dimensional images. The key thing with this is the radar astronomy rather than radio astronomy. The tracking is likely what's at play for the Uranus and Neptune though. https://en.wikipedia.org/wiki/Arecibo_Telescope https://en.wikipedia.org/wiki/Arecibo_Telescope > The round trip light time to objects beyond Saturn is longer than the 2.6-hour time that the telescope could track a celestial position, preventing radar observations of more distant objects. Uranus is about 2.5 light hours Neptune is about 4 light hours from us. Double that for the round trip time. The primary interesting part of this is getting the accurate ephemeris of near earth asteroids. https://www.lpi.usra.edu/meetings/acm2008/pdf/8285.pdf https://www.lpi.usra.edu/meetings/acm2008/pdf/8285.pdf > Arecibo Doppler measurements (2380-MHz, 12.6- cm) of asteroid 99942 Apophis, obtained in August 2005 and May 2006, have been combined with optical astrometry reported through August 2006 to produce a new orbit solution. https://www.sciencedirect.com/science/article/pii/S0019103521002591 https://www.sciencedirect.com/science/article/pii/S001910352... > During these encounters the Arecibo and Goldstone radar stations collected seven Doppler and 22 delay measurements of Bennu. For a general description of radar astrometry see Yeomans et al., 1987, Ostro et al., 2002. This wealth of ground-based tracking data allows an extremely accurate description of Bennu’s motion (Chesley et al., 2014). The trajectory of Bennu is deterministic until 2135, when a close encounter with Earth leads to strong scattering and makes the knowledge of its future motion statistical. --- So it looks like Green Bank will have improved transmitter and tracking. It won't have quite the sensitivity of Arecibo, but it's still one of the more impressive resources.
- snowwrestler 4y ago
  Thank you!
  - shagie 4y ago
    Some other "when digging around about radar astronomy and greenbank plans"... https://www.wboy.com/news/west-virginia/green-bank-telescope-in-west-virginia-finds-nasa-dart-mission-was-a-success/ https://www.wboy.com/news/west-virginia/green-bank-telescope... > The Green Bank Observatory, in conjunction with the Goldstone radio telescope in California, has been monitoring the pair of asteroids over the two weeks following the experiment on Sept. 26. Observations found not only that the trajectory had been changed successfully, but that it exceeded the initial expectations for how large the shift would be. From https://www.wvgazettemail.com/news/green-bank-telescope-helped-confirm-altered-path-of-asteroid-hit-by-nasa-spacecraft/article_dd58247e-0e04-54e3-b970-a4640b79cca0.html https://www.wvgazettemail.com/news/green-bank-telescope-help... > Green Bank Telescope radar observations of the asteroid Dimorphos after it was deliberately struck by a NASA spacecraft on Sept 26 were used to confirm the success of the first-ever full-scale demonstration of asteroid deflection technology The key here is that as mentioned Goldstone is the other radar astronomy capable observatory and its radar observations. RAdio Detection And Ranging. Those require the ability to transmit a radio pulse. But absouyltely it's neat what they're doing with it.

From the page on the test - https://greenbankobservatory.org/successful-test-paves-way-for-new-planetary-radar/ https://greenbankobservatory.org/successful-test-paves-way-f... > Using the information collected with this latest test, the participants will finalize a plan to develop a 500-kilowatt, high-power radar system that can image objects in the Solar System with unprecedented detail and sensitivity. The increased performance also will allow astronomers to use radar signals as far away as the orbits of Uranus and Neptune, increasing our understanding of the Solar System. > “The planned system will be a leap forward in radar science, allowing access to never before seen features of the Solar System from right here on Earth,” said Karen O’Neil, the Green Bank Observatory site director. That use of the word "unprecedented" and looking at Uranus and Neptune suggests to me that it will go further than Arecibo did... three decades ago. https://ui.adsabs.harvard.edu/abs/2000DDA....31.0803N/abstract https://ui.adsabs.harvard.edu/abs/2000DDA....31.0803N/abstra... > In October 1999 we obtained the first radar images of Saturn's rings, using the recently-upgraded Arecibo telescope operating at a wavelength of 12.6 cm. The opening angle of the rings was 19.9o, and dual-circular polarization data were collected over a period of 5 days. The resulting delay-Doppler maps have a range resolution of 100 msec and a frequency resolution of 2 kHz, corresponding to a spatial resolution cell of 15000 x 2000 km. Previous radar observations (e.g., Ostro et al. [1982] Icarus 49, 367) demonstrated the rings' high cross section and depolarization ratio, but did not yield 2-dimensional images. The key thing with this is the radar astronomy rather than radio astronomy. The tracking is likely what's at play for the Uranus and Neptune though. https://en.wikipedia.org/wiki/Arecibo_Telescope https://en.wikipedia.org/wiki/Arecibo_Telescope > The round trip light time to objects beyond Saturn is longer than the 2.6-hour time that the telescope could track a celestial position, preventing radar observations of more distant objects. Uranus is about 2.5 light hours Neptune is about 4 light hours from us. Double that for the round trip time. The primary interesting part of this is getting the accurate ephemeris of near earth asteroids. https://www.lpi.usra.edu/meetings/acm2008/pdf/8285.pdf https://www.lpi.usra.edu/meetings/acm2008/pdf/8285.pdf > Arecibo Doppler measurements (2380-MHz, 12.6- cm) of asteroid 99942 Apophis, obtained in August 2005 and May 2006, have been combined with optical astrometry reported through August 2006 to produce a new orbit solution. https://www.sciencedirect.com/science/article/pii/S0019103521002591 https://www.sciencedirect.com/science/article/pii/S001910352... > During these encounters the Arecibo and Goldstone radar stations collected seven Doppler and 22 delay measurements of Bennu. For a general description of radar astrometry see Yeomans et al., 1987, Ostro et al., 2002. This wealth of ground-based tracking data allows an extremely accurate description of Bennu’s motion (Chesley et al., 2014). The trajectory of Bennu is deterministic until 2135, when a close encounter with Earth leads to strong scattering and makes the knowledge of its future motion statistical. --- So it looks like Green Bank will have improved transmitter and tracking. It won't have quite the sensitivity of Arecibo, but it's still one of the more impressive resources.

snowwrestler 4y ago
Thank you!
- shagie 4y ago
  Some other "when digging around about radar astronomy and greenbank plans"... https://www.wboy.com/news/west-virginia/green-bank-telescope-in-west-virginia-finds-nasa-dart-mission-was-a-success/ https://www.wboy.com/news/west-virginia/green-bank-telescope... > The Green Bank Observatory, in conjunction with the Goldstone radio telescope in California, has been monitoring the pair of asteroids over the two weeks following the experiment on Sept. 26. Observations found not only that the trajectory had been changed successfully, but that it exceeded the initial expectations for how large the shift would be. From https://www.wvgazettemail.com/news/green-bank-telescope-helped-confirm-altered-path-of-asteroid-hit-by-nasa-spacecraft/article_dd58247e-0e04-54e3-b970-a4640b79cca0.html https://www.wvgazettemail.com/news/green-bank-telescope-help... > Green Bank Telescope radar observations of the asteroid Dimorphos after it was deliberately struck by a NASA spacecraft on Sept 26 were used to confirm the success of the first-ever full-scale demonstration of asteroid deflection technology The key here is that as mentioned Goldstone is the other radar astronomy capable observatory and its radar observations. RAdio Detection And Ranging. Those require the ability to transmit a radio pulse. But absouyltely it's neat what they're doing with it.