GBT Prime Focus RFI surveys - 2003

Summary of RFI surveys
Date Band Project Code Backend(s) Types of Data
2003 May 25 280-400 MHz TGBT02C_002_01 ACS(200MHz) Az rotation
2003 Jun 17 700-900 MHz TMIT_RFI_800 ACS(200MHz) Az rotation
2003 Jun 23 700-900 MHz TMIT_RFI_800_02 ACS(200MHz) Az rotation
2003 Jul 03 (night) 280-400 MHz TMIT_RFI_340 ACS(200MHz), PFS Az rotation, el=6; Az fixed, el=77
2003 Jul 04 (day) 280-400 MHz TMIT_RFI_340_02 ACS(200MHz) Az rotation, el=6; Az fixed, el=77
2003 Jul 18 (night) 900-1240 MHz TRFI_PF2_01 ACS(200MHz) Az rotation, el=6; Az fixed, el=77
2003 Jul 18 (day) 900-1100 MHz TRFI_PF2_02 ACS(200MHz) Az rotation, el=6;
2003 Jul 19 (day) 900-1100 MHz TRFI_PF2_03 ACS(200MHz) Peaks, Off/On
2003 Oct 19 (night) 400-450 MHz TRFI450_101903 ACS(50MHz) Az rotation, el=7;
2003 Oct 19 (day) 400-450 MHz TRFI450_OCT19 ACS(50MHz) Az rotation, el=7;
2003 Dec 02 (day) 500-700 MHz TRCO_2DEC03 ACS(200MHz) Az rotation, el=7;
2004 Feb 24 (night) 700-900 MHz TRCOFEB24 ACS(200MHz) Az rotation, el=7;
All ACS spectra done with 200 MHz bandwidth, 1-second noise switching, 2 second integrations, 1080 arcmin/min az rate (i.e, one 360 deg rotation in 20 minutes).

Download ascii files

Each of these files, when "gunzip"ed and un-tarred, becomes a directory with 600 ascii files, each file contains 4 spectra taken at a particular azimuth. The file has a header indicating the azimuth and time. The data have been calibrated and are in units of Janskys, i.e., 10**-26 watts per sq. meter per Hz. The columns in the table are 1) frequency, next spectral data in 2) Left circular polarization, 3) right circular polarization, and columns 4) and 5) is the same data with an 11-point median subtracted.
Data from May 25. Sweep in azimuth at 1080 arcmin/min. 600 spectra spaced (360/600) degrees apart. Elevation 7 degrees.
Scan 157, sweep from 90 to 450 azimuth. (49 MB)
Scan 158, sweep from 360 to 0 azimuth. (42 MB)

Some preliminary data from July 3.

Note that the RFI spikes spaced at 2 MHz have been traced to the active surface controllers. These features are eliminated in subsequent runs by turning off the power to the active surface electronics. This is not a problem because the active surface is not needed at frequencies below 8 GHz.

Download sample PFS data

A binary file containing the first second of PFS data collected July 3 may be downloaded through this link (20 MB)

Summary Raw Data Plots

Azimuth spins averaged over all directions
Date Band Scans in average Elevation
June 17 (Night) 750-850MHz 166,167 7.1°
June 23 (Day) 750-850MHz 39, 40 7.1°
July 03 (Night) 280-400MHz 19,20,21,22 6.1°
July 04 (Day) 280-400MHz 11, 12 6.1°
July 18 (Night) 900-1100MHz 31,32,33,34 6.1°
July 18 (Day) 900-1100MHz 27,28,29,30 6.1°