System Gain Calibration: Difference between revisions

From EOVSA Wiki
Jump to navigation Jump to search
(Created page with "== Gain Control "Knobs" == EOVSA has a series of attenuators in the frontend and downconverter analog system and digital gain controls in the digital system. File:Eovsa_gain...")
 
Line 1: Line 1:
== Gain Control "Knobs" ==
== Gain Control "Knobs" ==
EOVSA has a series of attenuators in the frontend and downconverter analog system and digital gain controls in the digital system.
[[File:Eovsa_gain_controls.png|thumb|400px|EOVSA Gain Control "Knobs"]] Non-solar radio interferometers can make the assumption that the system noise is dominated by the relatively uniform sky, but this is not at all valid for the Sun--the Sun dominates the system noise, and can be highly variable, especially during flares and other radio outbursts.  This is a main reason why it is necessary to design solar-dedicated instruments for observing the Sun.  In order to cope with the high and variable noise from the Sun, EOVSA is equipped with a series of attenuators, two RF attenuators in the frontend, and an IF attenuator in the analog downconverter.  In addition, it is possible to change the gain via parameters (ADC Attenuation, FFT Shift, and Equalizer Coefficients) in the digital correlator.  This table lists the various gain control points, their purpose, and other relevant information.
[[File:Eovsa_gain_controls.png|thumb|400px|EOVSA Gain Control "Knobs"]]


== Gain Calibration Procedure ==
== Gain Calibration Procedure ==

Revision as of 00:24, 8 August 2016

Gain Control "Knobs"

EOVSA Gain Control "Knobs"

Non-solar radio interferometers can make the assumption that the system noise is dominated by the relatively uniform sky, but this is not at all valid for the Sun--the Sun dominates the system noise, and can be highly variable, especially during flares and other radio outbursts. This is a main reason why it is necessary to design solar-dedicated instruments for observing the Sun. In order to cope with the high and variable noise from the Sun, EOVSA is equipped with a series of attenuators, two RF attenuators in the frontend, and an IF attenuator in the analog downconverter. In addition, it is possible to change the gain via parameters (ADC Attenuation, FFT Shift, and Equalizer Coefficients) in the digital correlator. This table lists the various gain control points, their purpose, and other relevant information.

Gain Calibration Procedure