A Cyberinfrastructure platform to meet the needs of data intensive radio astronomy on route to the SKA

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PHISCC RFI working Group

PHISCC RFI working Group

Owner: Anja Schroeder

Group members: 27

Brief description: This group combines and supports all RFI mitigation efforts for the SKA pathfinders and precursors

RFI mitigation is a very diverse topic with users from different backgrounds (e.g., engineers, observer, software developer). This working group tries to get all interested parties together and encourages interdisciplinary communication on the one hand and exchange of information on activities in one's own field on the other.

RFI mitigation methods are:

1. Prevention: remove RFI culprits from site.

2. Permits: if a culprit cannot be removed, a permit might be given that restricts its usage in terms of time (e.g., during the day or for a given time for testing purposes) and/or distance from an antenna.

3. RFI monitoring: The monitoring serves several purposes:

    a. Control over known RFI culprits on site and their permits

    b. Occupancy plots for observing strategies, resolved in time and direction

    c. Identification of new RFI on site (that is, RFI without a permit)

4. Observation schedule strategy: Observing can be scheduled in time and with position in the sky according to the presence of known RFI sources (that includes permits and RFI culprits outside the site).

5. Observing signal strategy: While observing the signal coming from a known RFI source direction can be nulled out. Other possible strategies can be added.

5. RFI flagging: RFI signatures vary so more than one flagging algorithm (some more specific than others) will serve different purposes (e.g., to build a data base of different RFIs and their identification; to remove RFI signals from further analysis of the data; to study RFI for SETI, etc). Thus this item can be subdivided by the purpose of the flagging.

6. RFI excision: a contentious topic but useful in some science cases of. Sub-categories of this item should cover the science cases and find out how excision (and where in the signal chain) could help.

7. RFI subtraction. RFI could be subtracted from the data. This is a known strategy in other science areas where high background prevents signal detection (e.g., medicine). Various statistical methods can be listed here.


A brief note on the name of the group: While the group name (historically) refers to the PHISCC = 'Pre-cursor HI Science Coordination Committee', it should not be restricted to HI science alone; RFI is a topic that concerns every kind of radio astronomy. So, every one is welcome, not only HI scientists. 


Membership criteria:

Anyone who is interested in RFI mitigation at the SKA pathfinder/precursor sites and in pathfinder/precursor survey data