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[[Anchor(beginOfPage)]] <<Anchor(beginOfPage)>>

<<TableOfContents(5)>>
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|| || Type || Channel Width || Bandwidth || Receiver (width mode) || Remark ||
|| '''1 MHz''' || Filterbank || 1 MHz || 4x256 MHz, 2x512 MHz, or, 1x1GHz || EMIR || (1) ||
|| '''4 MHz''' || Filterbanks || 4 MHz || 8 or 9 x 1GHz || EMIR, either HERA1 or HERA2 (wide) || (2) ||
|| '''WILMA''' || Autocorrelator || 2 MHz || 16 or 18 x 930 MHz || EMIR, HERA (wide) || (3) ||
|| '''VESPA''' || Autocorrelator || 3.3 kHz-1.25 MHz || 10-512 MHz || EMIR, HERA (narrow) || (4) ||
|| '''XPOL''' || VESPA || 40kHz-1.25MHz || 120-640MHz || EMIR || (5) ||
|| '''ABBA''' || || || || MAMBO || (6) ||
|| || Type || Channel Width || Bandwidth || Receiver (width mode) || [[http://www.iram.es/IRAMES/mainWiki/TelescopeSystemStatus#BackendStatus|Status]] || Remark ||
|| '''4 MHz''' || Filterbanks || 4 MHz || 8 or 9 x 1GHz || EMIR, either HERA1 or HERA2 (wide) || {{attachment:haken.gif}} || (1) ||
|| '''WILMA''' || Autocorrelator || 2 MHz || 16 or 18 x 930 MHz || EMIR, HERA (wide) || {{attachment:haken.gif}} || (2) ||
|| '''FTS''' || FFTS || 195 kHz || 2x4 GHz || EMIR || {{attachment:kreuz.gif}} || (4.1) ||
|| '''FTS''' || FFTS || 195 kHz || 8x4 GHz || EMIR, HERA || {{attachment:kreuz.gif}} || (4.2) ||
|| '''FTS''' || FFTS || 50 kHz || || EMIR, HERA || {{attachment:kreuz.gif}} || (4.3) ||
|| '''VESPA''' || Autocorrelator || 3.3 kHz-1.25 MHz || 10-512 MHz || EMIR, HERA (narrow) || {{attachment:haken.gif}} || (5) ||
|| '''XPOL''' || VESPA || 40kHz-1.25MHz || 120-640MHz || EMIR || {{attachment:haken.gif}} || (6) ||
|| '''ABBA2''' || || || || MAMBO2 || {{attachment:haken.gif}} || (7) ||
|| '''nbc''' || continuum || 1 GHz || || || {{attachment:haken.gif}} || (8) ||
|| '''bbc''' || continuum || 8 GHz || || || {{attachment:kreuz.gif}} || (9) ||
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For more information on the capabilities of EMIR, see [http://www.iram.es/IRAMES/mainWiki/EmirforAstronomers here]. In general, several backends can be attached to one receiver. Exceptions are listed below. The [http://www.iram.es/IRAMES/documents/ncs30mPako/Current/PDF/pako.pdf pako manual] describes in detail how to configure the backends.

 1. '''1MHz Filterbank''': max. 4 parts; series, parallel, or mixed mode possible; using the 1MHz filterbank with 1GHz bandwidth excludes the use of VESPA with the same receiver. The filterbank can be shifted in multiples of 32MHz from the center frequency of the connected receiver.
See [[http://www.iram.es/IRAMES/mainWiki/TelescopeSystemStatus|here]], for the present status of the backends. For more information on the capabilities of EMIR, see [[http://www.iram.es/IRAMES/mainWiki/EmirforAstronomers|here]]. In general, several backends can be attached to one receiver. Exceptions are listed below. The [[http://www.iram.es/IRAMES/documents/ncs30mPako/Current/PDF/pako.pdf|pako manual]] describes in detail how to configure the backends.
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 1. '''WILMA''': [http://www.iram.fr/IRAMFR/TA/backend/veleta/wilma/index.htm The Wideband Line Multiple Autocorrelator] for EMIR and HERA  1. '''WILMA''': [[http://www.iram.fr/IRAMFR/TA/backend/veleta/wilma/index.htm|The Wideband Line Multiple Autocorrelator]] for EMIR and HERA
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 1. '''VESPA''': [http://www.iram.fr/IRAMFR/TA/backend/veleta/vespa/index.htm The Versatile SPectrometer Array]. Up to 18000 channels. In connection with HERA (9 pixels) the following combinations of resolution (kHz) and bandwidth (MHz) are possible: (20/40), (40,80), (80, 160), (320,320), (1250, 640); [http://www.iram.es/IRAMES/otherDocuments/manuals/vespa_ug.ps VESPA User Guide (2002)], [http://www.iram.es/IRAMFR/ARN/dec02/node6.html Summary in IRAM Newsletter No. 54 (Dec 2002)], local contact: G. Paubert  1. '''1MHz Filterbank''': max. 4 parts; series, parallel, or mixed mode possible; using the 1MHz filterbank with 1GHz bandwidth excludes the use of VESPA with the same receiver. The filterbank can be shifted in multiples of 32MHz from the center frequency of the connected receiver. '''Deactivated since 4/2008'''

 1. '''Fast Fourier Transform Spectrometer (FTS)
''': for the winter semester 2010/11 we offer 8 units covering 2x4GHz of bandwidth with a fixed resolution of 195kHz for EMIR. During July 2011, the FTS and the FTS are upgraded to 32GHz bandwidth with 195 resolution for EMIR and HERA. During this time, none of the FTS units will be available for observations. See the [[http://www.iram.es/IRAMES/mainWiki/TelescopeSystemStatus#BackendStatus|backend status page]].

 1. '''VESPA''': [
[http://www.iram.fr/IRAMFR/TA/backend/veleta/vespa/index.htm|The Versatile SPectrometer Array]]. Up to 18000 channels. In connection with HERA (9 pixels) the following combinations of resolution (kHz) and bandwidth (MHz) are possible: (20/40), (40,80), (80, 160), (320,320), (1250, 640); [[http://www.iram.es/IRAMES/otherDocuments/manuals/vespa_ug.ps|VESPA User Guide (2002)]], [[http://www.iram.es/IRAMFR/ARN/dec02/node6.html|Summary in IRAM Newsletter No. 54 (Dec 2002)]], local contact: G. Paubert
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 1. '''Continuum backend''' with 1GHz width, is still the old system used for the ABCD receivers

 1. '''Continuum backend''' with 8GHz width, fully exploiting the increased bandwidth of EMIR, is in preparation.

== Distribution of intermediate frequencies (IFs) to the backends (Status: July 2011) ==

=== IF distribution in preparation for end of July 2011 ===

{{attachment:fft_be2v2.JPG}} <<BR>>
'''Figure 2''': Planned IF distribution for 2011

=== Old IF distribution (Status: June 2011) ===

{{attachment:NEWBE_dec10v2.jpg}} <<BR>>
'''Figure 1''': IF distribution (16-Dec-2010 SS/CK)

Backends for EMIR, HERA, MAMBO (after EMIR installation & commissioning in March/April 2009)

Type

Channel Width

Bandwidth

Receiver (width mode)

Status

Remark

4 MHz

Filterbanks

4 MHz

8 or 9 x 1GHz

EMIR, either HERA1 or HERA2 (wide)

haken.gif

(1)

WILMA

Autocorrelator

2 MHz

16 or 18 x 930 MHz

EMIR, HERA (wide)

haken.gif

(2)

FTS

FFTS

195 kHz

2x4 GHz

EMIR

kreuz.gif

(4.1)

FTS

FFTS

195 kHz

8x4 GHz

EMIR, HERA

kreuz.gif

(4.2)

FTS

FFTS

50 kHz

EMIR, HERA

kreuz.gif

(4.3)

VESPA

Autocorrelator

3.3 kHz-1.25 MHz

10-512 MHz

EMIR, HERA (narrow)

haken.gif

(5)

XPOL

VESPA

40kHz-1.25MHz

120-640MHz

EMIR

haken.gif

(6)

ABBA2

MAMBO2

haken.gif

(7)

nbc

continuum

1 GHz

haken.gif

(8)

bbc

continuum

8 GHz

kreuz.gif

(9)

See here, for the present status of the backends. For more information on the capabilities of EMIR, see here. In general, several backends can be attached to one receiver. Exceptions are listed below. The pako manual describes in detail how to configure the backends.

  1. 4MHz Filterbank: max. 9 parts; use of the 4MHz filterbank excludes the use of VESPA on the same receiver. Frequency switching not available. While the channel spacing is 4MHz, the 3dB width is 5.4MHz and the noise equivalent width is 6.5 MHz

  2. WILMA: The Wideband Line Multiple Autocorrelator for EMIR and HERA

  3. 1MHz Filterbank: max. 4 parts; series, parallel, or mixed mode possible; using the 1MHz filterbank with 1GHz bandwidth excludes the use of VESPA with the same receiver. The filterbank can be shifted in multiples of 32MHz from the center frequency of the connected receiver. Deactivated since 4/2008

  4. Fast Fourier Transform Spectrometer (FTS): for the winter semester 2010/11 we offer 8 units covering 2x4GHz of bandwidth with a fixed resolution of 195kHz for EMIR. During July 2011, the FTS and the FTS are upgraded to 32GHz bandwidth with 195 resolution for EMIR and HERA. During this time, none of the FTS units will be available for observations. See the backend status page.

  5. VESPA: The Versatile SPectrometer Array. Up to 18000 channels. In connection with HERA (9 pixels) the following combinations of resolution (kHz) and bandwidth (MHz) are possible: (20/40), (40,80), (80, 160), (320,320), (1250, 640); VESPA User Guide (2002), Summary in IRAM Newsletter No. 54 (Dec 2002), local contact: G. Paubert

  6. XPOL: Line and continuum polarimetry is possible at the 30m using a new type of IF polarimeter designated XPOL. The central feature of XPOL is the correlator VESPA where the IF signals from two orthogonally polarized receivers are cross correlated to determine the four Stokes parameters. A manual is in preparation, contact: C. Thum

  7. ABBA1 and ABBA2 (Adc Bolometer Backend) are the bolometer backends, i.e. dedicated PCs connected to the bolometers.

  8. Continuum backend with 1GHz width, is still the old system used for the ABCD receivers

  9. Continuum backend with 8GHz width, fully exploiting the increased bandwidth of EMIR, is in preparation.

Distribution of intermediate frequencies (IFs) to the backends (Status: July 2011)

IF distribution in preparation for end of July 2011

fft_be2v2.JPG
Figure 2: Planned IF distribution for 2011

Old IF distribution (Status: June 2011)

NEWBE_dec10v2.jpg
Figure 1: IF distribution (16-Dec-2010 SS/CK)

Backends (last edited 2023-04-02 21:41:14 by damour)