Copyright © National Academy of Sciences. All rights reserved.
Solar and Space Physics: A Science for a Technological Society
318
SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY
FASR comprises three antenna arrays that are designed to observe meter (FASR C), decimeter (FASR B),
and centimeter wavelengths (FASR A). The instrument exploits the long heritage of Fourier synthesis imaging developed over several decades in radioastronomy. The techniques are mature, and the technologies
robust. High-level instrument specifications are given in Box 10.2.
10.5.4.4 Coronal Solar Magnetism Observatory
The SHP panel’s other high-priority candidate for the NSF midscale line is the COSMO large-aperture
coronagraph and chromosphere and prominence magnetometer, 38 which would complement the ATST
and FASR. Until explosively released, most of the mass and energy that produce space weather events are
stored in the coronal magnetic field. Coronal faintness is an observational challenge especially for sensitive
magnetic and velocity measurements. Responding to a next-step suggestion of the 2003 decadal survey, 39
COSMO is proposed as a suite of three instruments: a ground-based, 1.5-m-aperture solar coronagraph
supported by a 12-cm-aperture white-light K-coronagraph (under construction) and a 20-cm-aperture
chromosphere and prominence magnetometer. COSMO will be a facility for use by the solar physics
research community. The facility will take continuous daytime synoptic measurements of magnetic fields
38 S. Tomczyk et al., COSMO, The Coronal Solar Magnetism Observatory, white paper submitted to the Decadal Strategy for Solar
and Space Physics (Heliophysics), Paper 268; J. Burkepile et al., The Importance of Ground-Based Observations of the Solar Corona,
white paper submitted to the Decadal Strategy for Solar and Space Physics (Heliophysics), Paper 25; S. McIntosh et al., The Solar
Chromosphere: The Inner Frontier of the Heliospheric System, white paper submitted to the Decadal Strategy for Solar and Space
Physics (Heliophysics), Paper 193.
39 NRC, The Sun to the Earth—and Beyond: A Decadal Research Strategy in Solar and Space Physics, 2003.
BOX 10.2 FASR SPECIFICATIONS
Angular resolution
20/n GHz arcsec
Frequency range
50 MHz to 21 GHz
Number of data channels
2 (dual polarization)
Frequency bandwidth
500 MHz per channel
Frequency resolution
Instrumental: 4,000 channels
Scientific: minimum (1%, 5 MHz)
Time resolution
About 1 s (full spectrum sweep)
20 ms (dwell)
Polarization
Full Stokes (intensity and linear polarization and circular polarization)
Number of antennas deployed
A (2-21 GHz): about 100
B (0.3-2.5 GHz): about 70
C (50-350 MHz): about 50
Size of antennas
A (2-21 GHz): 2 m
B (0.3-2.5 GHz): 6 m
C (50-350 MHz): log-periodic dipole array
Array size
4.25 km east-west x 3.75 km north-south
Absolute positions
1 arcsec
Absolute flux calibration
<10%
Solar and Space Physics: A Science for a Technological Society
318
SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY
FASR comprises three antenna arrays that are designed to observe meter (FASR C), decimeter (FASR B),
and centimeter wavelengths (FASR A). The instrument exploits the long heritage of Fourier synthesis imaging developed over several decades in radioastronomy. The techniques are mature, and the technologies
robust. High-level instrument specifications are given in Box 10.2.
10.5.4.4 Coronal Solar Magnetism Observatory
The SHP panel’s other high-priority candidate for the NSF midscale line is the COSMO large-aperture
coronagraph and chromosphere and prominence magnetometer, 38 which would complement the ATST
and FASR. Until explosively released, most of the mass and energy that produce space weather events are
stored in the coronal magnetic field. Coronal faintness is an observational challenge especially for sensitive
magnetic and velocity measurements. Responding to a next-step suggestion of the 2003 decadal survey, 39
COSMO is proposed as a suite of three instruments: a ground-based, 1.5-m-aperture solar coronagraph
supported by a 12-cm-aperture white-light K-coronagraph (under construction) and a 20-cm-aperture
chromosphere and prominence magnetometer. COSMO will be a facility for use by the solar physics
research community. The facility will take continuous daytime synoptic measurements of magnetic fields
38 S. Tomczyk et al., COSMO, The Coronal Solar Magnetism Observatory, white paper submitted to the Decadal Strategy for Solar
and Space Physics (Heliophysics), Paper 268; J. Burkepile et al., The Importance of Ground-Based Observations of the Solar Corona,
white paper submitted to the Decadal Strategy for Solar and Space Physics (Heliophysics), Paper 25; S. McIntosh et al., The Solar
Chromosphere: The Inner Frontier of the Heliospheric System, white paper submitted to the Decadal Strategy for Solar and Space
Physics (Heliophysics), Paper 193.
39 NRC, The Sun to the Earth—and Beyond: A Decadal Research Strategy in Solar and Space Physics, 2003.
BOX 10.2 FASR SPECIFICATIONS
Angular resolution
20/n GHz arcsec
Frequency range
50 MHz to 21 GHz
Number of data channels
2 (dual polarization)
Frequency bandwidth
500 MHz per channel
Frequency resolution
Instrumental: 4,000 channels
Scientific: minimum (1%, 5 MHz)
Time resolution
About 1 s (full spectrum sweep)
20 ms (dwell)
Polarization
Full Stokes (intensity and linear polarization and circular polarization)
Number of antennas deployed
A (2-21 GHz): about 100
B (0.3-2.5 GHz): about 70
C (50-350 MHz): about 50
Size of antennas
A (2-21 GHz): 2 m
B (0.3-2.5 GHz): 6 m
C (50-350 MHz): log-periodic dipole array
Array size
4.25 km east-west x 3.75 km north-south
Absolute positions
1 arcsec
Absolute flux calibration
<10%