Arecibo Observatory: S-Low Band Receiver

Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://www.naic.edu/~astro/RXstatus/Slow/slow.shtml
Äàòà èçìåíåíèÿ: Unknown
Äàòà èíäåêñèðîâàíèÿ: Sun Feb 3 20:54:22 2013
Êîäèðîâêà:
Ïîèñêîâûå ñëîâà: cygnus

Arecibo Observatory: S-Low Band Receiver To leave the frames behind, click here

S-Low Receiver

Basic Information

Calibration & Beam Parameters

RFI Situation

Recent Events

Receiver History

Technical Description

Contact Info

1. Basic Information:

Frequency Range (GHz):	1.7 - 3.0
Name and Number:	*sbl, sbl1_2, and 7, 71 ()**
Measured Sensitivity (K/Jy):	~ 8 ()**
Measured System Temp (K):	~ 34 ()**
Native Polarization:	Dual Linear
Beam Size (at 2.5 GHz):	1.8 x 2.0 arcmin
Available Filters:	3 Bandpass filters, 1.7 - 1.88, 2.04 - 2.4, & 2.6 - 3.0 GHz can be used in any combination or none
Warnings and Important Notes:	This Rx has a lot of Resonance modesin the OMT

* The two different names and numbers are used for different IF/LO paths in IFSETUP command
** See calibration info below for a more accurate description of the telescope parameters

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2. Calibration & Beam Parameters:

Gain and Tsys

Cal Values

Beam Maps

Polarization

Misc. Info

Beam Maps
No beam map at this frequency is yet available, however some beam-related parameters can be viewed here. The plots show coma, 1st-side lobe level, main beam effeciency and main beam + 1st side-lobe effeciency at different frequency ranges.

Here is a recommended internal memo on this subject : Main Beam and First Sidelobe Parameters for Arecibo's Receiver Systems by C. Heiles et al (5MB PS file )
Polarization

Polarization properties of this Rx has not been determined yet. However, here is an useful documents The Mueller Matrix Parameters for Arecibo's Receiver Systems by C. Heiles et al (~5MB, PS file)

A short introduction to digital spectropolarimetry written be Carl Heiles can be found in this PDF file
Misc. Info
To see an up-to-date plot of Tsys, just type tsys on your terminal after logging into Arecibo's computer network. It will open an IDL environment and show a plot of Tsys vs day number for all Rxs. You may then follow the instructions to plot only one Rx.
More information on calibration techniques can be found in Chris Salter's "Note relevant to Spectral Line User's"

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3. RFI situation:

Spectral scans covering the S-low receiver's bandpass was taken (by S. Stanimirovic) on Sep 20 2001. The measurement was from 1800 MHz to 2950 MHz. The largest RFI seen were: at 1940 Mhz from cellular phones, at 2700 MHz from the 2nd harmonics of the San Juan airport radar at 1330/1350 MHz, and at 2900-3100 MHz from the radar at Pico del Este.

The figure ( available here) plots the spectrum from 1800 Mhz to 2950 Mhz. The resolution bandwidth was set to 3 Mhz. The system temperature is about 40 K. The red line averages 100 sweeps of the spectrum analyzer. Integrating the spectra gave -23.5 dbm (pol. A) and -24.3 dbm (pol. B). the top figure is polarization A and the bottom for polarization B.

This document lists all RFI spikes/features seen on the (2001) spectral scan. In addition, it lists the resonance modes seen in this receiver as well.

A few RFI-related useful links (on AO pages) are:

Fractional RFI in telescope data
How to look at RFI monitoring data taken with the telescope (X111) using IDL
Various RFI info

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4. Recent Events:

Recent events can be found in the electronics receiver log.

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5. Receiver History:

Used regularly by wide-band pulsar observers. This band has also been used for SETI observations.

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6. Technical Info:

To find out the technical details about this receiver, just click on the appropriate icon at the top of the Receiver tabel (Only internally available -- please contact the POC for anything specific).

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7. Contact Info:

For further information on this receiver, please contact T. Ghosh at
tghosh (append @naic.edu)

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