ALFA Performance Parameters

Title Description
Recent Band Averaged Measurements

This is the band averaged Gain, SEFD, Tsys, and Beam width for ALFA taken at regular intervals. The data is 100 Mhz centered at 1420 Mhz. The data is first plotted with all pixels together. The color is used to code the pixel number. After the combined plot there are 7 more plots showing each pixel by itself. For these plots the color is used to distinguish the source used.

For performance figures as a function of frequency, see the ALFA spectral scans.

ALFA spectral parameters & calibration
(2004 Nov 18)
This memo by Desh gives the details of the observations done to produce the spectral scans.
(2004 Nov 18)
The fit parameters for the spectral scans can be downloaded. These are the coefficients of the high order polynomial fit to the spectral scans. Details are given in the memo by Desh: ALFA spectral parameters & calibration
Spectral Scans (full band)
(2004 Nov 16)
Spectral scans across the full ALFA band.
  • System Gain (Gain)
  • System Temperature (Tsys)
  • System Equivalent Flux Density (SEFD)
  • Ratio of Tsys to Tcal (sys2cal)
Tcal (Full Band)
(2004 Nov 12)
The calibration diode characteristic is presented across the ALFA band of 1225MHz-1525MHz in a single plot. The fit parameters can be downloaded.
(2004 Oct 3)
The ALFA receiver temperature was measured across the bandwidth. The fit parameters can be downloaded.
(2004 Sep 7)
ALFA performance in the bandpass allowing OH measurements is described by Chris Salter and Tapasi Ghosh.
ALFA Tests Commissioning/Characterization
(2004 Aug 29)
An overview of the ALFA commissioning can be found in the presentation by Desh at the GALFA Meeting 3
OH Spectral Scans
(2004 Aug 27)
Spectral scans in the bandpass allowing OH measurements.
(2004 Aug 23)
The RFI from the ALFA motor was measured.
AZ-ZA Dependence
(2004 Jul 22)
The SEFD, Gain, and Tsys were measured as a function of telescope Zenith Angle (ZA).
Beam Maps
(2004 May 4)
A raster of Azimuth scans with steps of 1.5' in zenith-angle offset about the instantaneous direction of the continuum calibrator 3C286 was used to map the beam responses of all the 7 beams of ALFA.