GBT Radio Frequency Interference

Introduction GBT Receiver Plots by Band GBT RFI Monitoring Station Plots by Band Older Surveys and Band Summaries Known Sources Database Introduction The Green Bank Radio Frequency Interference (RFI) Protection Group would like to offer two primary tools to observers for the purposes of RFI avoidance and mitigation. One of these tools is an archive of RFI scans which will give the observer an idea of spectral occupancy as seen by the GBT receivers themselves, and (eventually) from the GBT RFI Monitoring Station (pictured right). The second, still under construction, will be a RFI Database which provides details on persistent, identified RFI sources including coordination information where applicable.  For now, we have a Table of Known RFI Sources and a number of Older Surveys and Band Summaries  linked below. To maximize your chances of RFI avoidance, we advise the following: 1) Consult the latest GBT RFI plots to determine whether the spectrum you wish to observe is typically clear, or occupied by RFI. 2) Consult the Table of Known RFI Sources and/or the Surveys and Band Summaries  to determine whether the source of the RFI is well known and/or likely to be something we can coordinate with (broadcast television, for instance, isn't going to coordinate with us). 3) Contact a member of the Green Bank RFI Group to determine whether coordination is possible. If it is, you will need to obtain a fixed window from the dynamic scheduling group for your observation, and the RFI group can then arrange coordination. Usually, by the time RFI is experienced during observation, it is too late to do anything about it, but it is still worth reporting, in case it can be mitigated in advance of future observations. For additional information email interference@nrao.edu.

GBT Receiver Plots by Band

RFI scans are performed routinely by the operators during gaps between astronomical observations. All GBT RFI data is permanently stored as .fits files at:
/home/gbtdata/TRFI_MMDDYY_RN where MM is "number" for the month, DD is the day of the month, YY is the last two digits of the year, R is the receiver letter designation (see below) and N is the session number for that particular day (1,2, 3 etc.)

Prime Focus 1 340 MHz   R=3
Prime Focus 1 450 MHz   R=4
Prime Focus 1 600 MHz   R=6
Prime Focus 1 800 MHz   R=8
Prime Focus 2 R=P
L Band R=L
S Band R=S
C Band R=C
X Band R=X
Ku Band R=U
Ka Band R=A
KFPA R=K
Q Band R=Q
W band R=W

The RFI group routinely (weekly) creates plots from the most recent RFI scans and displays them here. Previous plots may be re-generated from the GBT archives using GBTIDL.

Prime Focus 1-1 3(0.29 to 0.395 GHz) Latest interference plots 06_01_14 05_05_14 05_03_14 04_24_14 03_27_14 06_13_13 02_15_13 12_17_12 11_28_12 11_20_12 09_05_12 08_16_12 06_28_12 02_25_12 10_18_11 10_09_11 10_05_11 06_01_11 04_07_11 03_30_11 03_01_11 12_31_10 12_28_10 11_03_10 08_29_10 08_26_10 08_16_10 08_09_10 08_02_10 06_02_10 05_25_10 05_06_10 03_23_10 01_02_10 12_26_09 12_24_09 11_30_09 11_23_09 11_13_09 11_03_09 09_02_09 08_05_09	Prime Focus 1-2 4(0.385 to 0.520 GHz) Latest interference plots 07_06_12 06_11_12 09_14_11 10_27_09 09_08_09 02_26_09 11_28_08
Prime Focus 1-3 6(0.51 to 0.69 GHz) Latest interference plots 06_12_12 10_31_09 11_08_08	Prime Focus 1-4 8(0.68 to 0.92 GHz) Latest interference plots 05_23_14 04_09_14 01_11_14 12_07_13 11_30_13 10_29_13 10_04_13 08_01_13 07_14_13 06_20_13 05_18_13 05_10_13 03_13_13 02_21_13 01_10_13 12_19_12 11_30_12 10_26_12 10_19_12 09_15_12 09_03_12 08_23_12 08_09_12 06_13_12 05_16_12 05_08_12 03_08_12 02_19_12 01_20_12 01_11_12 10_19_11 09_12_11 09_06_11 07_25_11 07_17_11 06_19_11 05_29_11 04_22_11 03_20_11 03_15_11 02_22_11 02_20_11 12_09_10 11_14_10 10_20_10 09_28_10 09_10_10 08_17_10 07_23_10 07_18_10 06_11_10 05_22_10 05_18_10 04_17_10 04_13_10 03_17_10 03_11_10 01_06_10 12_15_09 11_18_09 10_16_09 10_13_09 09_16_09 08_11_09 07_15_09 04_24_09 02_19_09 12_16_08 08_26_08 08_21_08
Prime Focus 2 P(0.91 to 1.23 GHz) Latest interference plots 02_04_14 02_06_12 01_30_12 06_30_11 09_28_09 05_27_09 01_30_09 09_29_08	Gregorian L Band (1.15 to 1.73 GHz) Latest interference plots 06_22_14 06_01_14 05_22_14 03_14_14 02_15_14 02_05_14 02_02_14 01_03_14 12_12_13 10_22_13 10_01_13 09_16_13 09_05_13 07_21_13 07_12_13 05_23_13 05_14_13 03_12_13 02_28_13 02_19_13 01_26_13 01_11_13 12_28_12 12_01_12 11_23_12 11_07_12 11_01_12 10_22_12 10_15_12 10_06_12 09_18_12 07_21_12 07_14_12 06_06_12 05_13_12 04_10_12 02_19_12 02_15_12 02_01_12 01_25_12 01_11_12 12_30_11 12_14_11 12_06_11 11_21_11 10_31_11 10_18_11 10_09_11 09_14_11 09_09_11 08_06_11 07_17_11 06_19_11 05_29_11 04_27_11 04_19_11 03_20_11 02_28_11 02_20_11 02_07_11 01_03_11 01_01_11 12_28_10 11_13_10 11_02_10 10_28_10 10_24_10 10_17_10 10_12_10 10_06_10 08_29_10 08_21_10 06_12_10 05_22_10 05_18_10 04_25_10 04_22_10 03_23_10 02_15_10 02_07_10 02_05_10 01_28_10 01_07_10 11_15_09 10_16_09 08_21_09 04_25_09 02_27_09 11_09_08 09_21_08 09_17_08 09_11_08 09_03_08 08_27_08
Gregorian S Band (1.73 to 2.6 GHz) Latest interference plots 06_22_14 05_22_14 04_21_14 11_30_13 09_26_13 07_21_13 05_14_13 04_12_13 02_28_13 01_27_13 01_14_13 10_26_12 10_21_12 09_18_12 09_03_12 05_14_12 04_14_12 02_25_12 01_29_12 11_21_11 10_20_11 10_10_11 07_17_11 05_29_11 05_16_11 05_03_11 04_22_11 03_22_11 02_28_11 02_21_11 02_07_11 01_01_11 11_14_10 11_06_10 10_31_10 10_16_10 10_10_10 10_06_10 09_27_10 06_10_10 05_22_10 04_18_10 01_13_10 01_10_10 11_30_09 09_02_09 06_18_09 05_24_09 11_09_08 09_30_08 09_02_08 08_22_08	Gregorian C Band (3.95 to 5.85 GHz) Latest interference plots 10_01_13 09_17_13 08_29_13 02_05_13 01_23_13 11_28_12 09_19_12 09_05_12 08_25_12 07_14_12 11_23_11 10_20_11 10_12_11 08_23_11 05_29_11 05_16_11 05_05_10 04_29_10 03_20_10 10_27_09 05_12_09 08_25_08
Gregorian X Band (8.2 to 10.0 GHz) Latest interference plots 07_26_14 05_31_14 05_09_14 04_14_14 12_03_13 10_03_13 07_20_13 06_07_13 04_14_13 04_03_13 02_17_13 01_26_13 12_04_12 11_27_12 09_20_12 09_15_12 09_05_12 09_01_12 08_31_12 08_23_12 07_21_12 04_10_12 02_27_12 02_16_12 02_01_12 01_24_12 01_10_12 12_15_11 11_23_11 11_07_11 10_31_11 10_19_11 10_08_11 09_13_11 09_09_11 08_05_11 07_17_11 05_29_11 05_09_11 05_03_11 04_23_11 04_02_11 03_30_11 03_23_11 02_21_11 02_06_11 01_10_11 01_03_11 12_31_10 12_28_10 12_14_10 11_17_10 11_10_10 10_29_10 10_14_10 10_10_10 10_08_10 09_27_10 09_14_10 09_04_10 08_30_10 08_27_10 08_21_10 08_16_10 06_12_10 06_04_10 05_22_10 05_01_10 04_26_10 04_18_10 04_05_10 03_20_10 02_14_10 01_09_10 12_24_09 11_27_09 10_25_09 06_11_09 06_05_09 04_24_09 10_29_08 10_23_08 09_30_08 09_17_08 09_02_08 08_25_08	Gregorian Ku Band (12.4 to 15.4 GHz) Latest interference plots 09_14_11 08_23_11 08_13_11 07_17_11 07_04_11 05_28_11 05_06_11 01_02_11 12_28_10 08_30_10 05_04_10 02_08_10 01_26_10 01_04_10 12_10_09 11_27_09 11_17_09 10_08_09 06_02_09
K-Band Focal Plane Array(17.6 to 24.3 GHz) Latest interference plots 03_31_14 03_16_14 03_06_14 03_04_14 12_03_13 01_02_13 04_13_12 04_07_12 02_27_12 02_01_12	Gregorian Ka Band (26.5 to 40 GHz) Latest interference plots 04_21_14 03_16_14 03_14_14 03_06_14 12_03_13 09_01_12
Gregorian Q-Band(40.0 to 50.0 GHz) Latest interference plots 01_02_13	Gregorian W-Band (68.0 to 92.0 GHz) Latest interference plots Under Development

GBT RFI Monitoring Station Plots by Band

This portion of the web page UNDER CONSTRUCTION.

Older Surveys and Band Summaries

• World Radio Astronomy Frequency Allocations

Known Sources Database