Title :
ALFA: a constellation mission for low frequency radioastronomy
Author :
Howard, Regan E. ; Jones, Dayton ; Blume, William ; Seybold, Calina
Author_Institution :
Orbital Sci. Corp., Germantown, MD, USA
Abstract :
The ALFA mission is proposed to be the first astronomical observatory to make high-resolution radio images in the vast region of the electromagnetic spectrum below Earth´s ionospheric cutoff between 30 kHz and 30 MHz. The ALFA imaging interferometer consists of 16 identical small satellites with dipole antennas and low frequency radio receivers, distributed in a spherical array 100 km in diameter, yielding images with thousands of times the resolution previously available in this frequency range. The array will be placed in a nearly circular distant retrograde orbit about the Earth, with a typical range of 106 km. Each satellite communicates directly with a small (11 m.), low-cost antenna at each DSN site, providing parallel data paths and continuous coverage. As a result, the array is resilient to individual satellite failures; observing by the rest of the array will be unaffected
Keywords :
aerospace instrumentation; artificial satellites; dipole antennas; mobile antennas; radioastronomical techniques; radiowave interferometry; 100 km; 11 m; 30 kHz to 30 MHz; ALFA; DSN site; Earth ionospheric cutoff; astronomical observatory; circular distant retrograde orbit; constellation mission; dipole antennas; electromagnetic spectrum; high-resolution radio images; imaging interferometer; low frequency radio receivers; low frequency radioastronomy; low-cost antenna; nasa; parallel data paths; spherical array; Dipole antennas; Earth; Electromagnetic spectrum; Frequency; High-resolution imaging; Observatories; Radio interferometry; Receiving antennas; Satellite antennas; Satellite broadcasting;
Conference_Titel :
Aerospace Conference Proceedings, 2000 IEEE
Conference_Location :
Big Sky, MT
Print_ISBN :
0-7803-5846-5
DOI :
10.1109/AERO.2000.879268
