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System - General

The 30-m telescope is now operating using the New Control System (NCS) (2005-11-30 HU)

NCS supports only source coordinates in Equatorial J2000.0 system. (More systems will be made available as soon as possible)

Observations near and towards the Sun are not yet supported.

NCS supports observing modes and source offsets in:

All 4 Switching Modes are supported by the NCS (total power, beam switching, wobbler switching, frequency switching.)

Observing modes supported by the NCS:

(./) Automatic calibration and processing of heterodyne data using the MIRA software is in operation for all observing modes. MIRA can also be used manually and offline.

/!\ Online data processing, in some circumstances, still may have problems with scans extending over midnight. Please check data and report problems to Albrecht Sievers. It may be safer to avoid long scans extending over midnight.

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Antenna

(./) OK

/!\ On 30.10.2007 the GISMO bolometer has been installed. It is in the beam of single pixel or HERA observation for all declinations smaller than 25 degrees. There is no alarm, so astronomers should be aware of this (RM 30.10.2007)

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Wobbler

Available under NCS.

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Pointing Model and Focus

The Pointing Model is maintained with respect to the receiver B100. The misalignment and focus error (D-focus) of the other receivers with respect to B100 is the following: 

  Rx       misal.(")       date            D_focus(mm)       date
 A100     0.16 ±0.06     27-Feb-07,        +0.09 ±0.03     13-Mar-07
 A230     1.34 ±0.18     27-Feb-07,        +0.43 ±0.02     13-Mar-07
 B100     0.00                              0.00
 B230     1.74 ±0.16     27-Feb-07,        +0.40 ±0.10     17-Apr-07
 C150     1.26 ±0.24      5-Feb-07,        +0.64 ±0.13     17-Apr-07
 C270     0.78 ±0.18      5-Feb-07,        +0.36 ±0.15     17-Apr-07
 D150     1.03 ±0.13     12-Mar-07,        +0.26 ±0.02     12-Mar-07
 D270     1.40 ±0.19     12-Mar-07,        +0.18 ±0.05     12-Mar-07

heterodyne: last model update: 2007-10-23, 40 points, previous rms = 3.44", new rms = 1.69"

bolometer: last model update: 2007-06-22, 36 points, previous rms = 3.03", new rms = 2.09"

/!\ Pointing on spectral line sources like SiO masers is not yet supported by the data processing.

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SIS Receivers

(./) A, B, C, D receivers are supported by NCS for observations.

(./) Image/Signal gain-ratio calibration is supported by NCS.

(./) A standard table of T_cold calibration temperatures for A, B, C, D receivers is implemented in NCS. This built-in table covers most frequencies. /!\ Outside this range, T_cold has to be set manually.

/!\ Note that the tables and plots at [http://gra-lx1.iram.es/mainWiki/ReceiverGroupColdloadPlots] appear to be out of date!

/!\ Tables and plots are now at [http://gra-lx1/mainWiki/ReceiverGroupColdLoadPlotsCurrent] 2007-10-11 dj

/!\ Receiver C150 shows low continuum signal at the higher frequencies (>168 GHz). It has to be fully checked. Use D150 instead. (2005-11-16)

Note: the last 2 points need to be checked and maybe corrected by the RX group!

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HERA

(./) HERA is supported by the NCS. (2006-02 HU)

Second polarization installed. BR (./) One previously blind pixel is now fixed (2006-04). BR SSB tuning tables for standard frequencies. BR Sideband rejections not determined (2004-12-01 AW). Use standard value of 0.1! BR

(./) For HERA calibration, measured values of the load temperatures are automatically used!

/!\ Watch the computer control of the derotator closely (2002-12-22). BR /!\ Make sure the derotator tracking is stopped after observations, i.e., set to zero degrees in "frame". BR

/!\ The automatic tuning of both HERA1 and 2 can be improved by manually changing the mixer current according to DJ; HERA Pool managers should be aware of this, and operators will receive training (2007-09-19 RM)

HERA 2 is more noisy than HERA 1, limiting HERA2's useful frequency range to below about 242 GHz (2006-09-27 HU according to info from SN)BR

Note: these comments on HERA need to be checked and, if necessary, corrected by the RX group!

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Pointing and Flux monitoring with SIS receivers:

Continuum instability ("ripple") can occur with all receivers, making pointing and focusing difficult.

In general some receivers are better than others in this respect as summarized here:

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Bolometers

(./) Bolometer Observations are supported by the NCS.

Mambo1: OFFLINE

/!\ Mambo2: has been removed to install Gismo (RM 30.10.2007)

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Backends

Support by NCS:

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Computer/Software

/!\ The 30-m telescope is now operating using the New Control System (NCS) (2005-11-30 HU). Note that the NCS supports most essential features, but still has some limitations! See the NCS documentation for details, in particular links from the Wiki [https://mrt-lx1.iram.es/mainWiki/OperationNotesObservers NCS Operation Notes for Observers]

/!\ Online data processing, in some circumstances, still may have problems with scans extending over midnight. Please check data and report problems to Albrecht Sievers. It may be safer to avoid long scans extending over midnight.

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Other Items

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Updates/History

To see the changes between the actual and the last version, please see Show Changes in the Wiki Interface. If you want to see the Revision History of this page, please see Get Info in the Wiki Interface.

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Legend

(./) : OKBR /!\ : WarningBR {X} : ErrorBR

The wiki markup of these icons is:

{{{(./) : OK /!\ : Warning {X} : Error }}}

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