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System - General

The 30-m telescope runs under the New Control System (NCS), see:

The 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.

Observing modes and source offsets in:

All 4 Switching Modes are supported:

Observations with "rotated" wobbler and the bolometer are possible within the pool; contact the pool manager, Stephane Leon, on how to prepare such observations. After finishing with rotated Wobbler, make sure that the operator puts the rotation back to exactly 0 degrees.

Observing modes:

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.

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Antenna

(./) OK

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Wobbler

(./) OK

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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: 2008-06-25, 29 points, previous rms = 2.58", new rms = 1.97"

bolometer: last model update: 2007-12-19, 46 points, previous rms = 2.33", new rms = 1.75"

/!\ 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

Image/Signal gain-ratio calibration is supported by NCS, processing in MIRA. It is highly recommended to use this feature!

A standard table of T_cold calibration temperatures for A, B, C, D receivers is implemented in the NCS. This built-in table covers most frequencies. /!\ Outside this range, T_cold has to be set manually, ask the RX engineers or operators! Tables and plots:

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

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HERA

Second polarization installed. 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). /!\ Make sure the derotator tracking is stopped after observations, i.e., set to zero degrees in "frame".

/!\ 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)

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Pointing with SIS receivers A, B, C, D and HERA

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

Mambo1 is OFFLINE

Mambo2 was re-installed and commissioned the week 13.11.2007/20.11.2007 (AS)

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Backends

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Computer/Software

/!\ The NCS supports most essential features, but still has some limitations; see the documentation for details. (see links above)

/!\ Online data processing, in a few 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.

/!\ Pako does not run under the default gildas version on mrt-lx3, mrt-lx2. Use gag_aug06 before starting pako (2008-01-15 AS). BR Note: the instructions to start pako explicitly say to run it on mrt-lx1. The trick suggested by AS for mrt-lx2, mrt-lx3 may work, but it is not guaranteed.

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Other Items

Remote observing via VNC is available from Granada, Grenoble, and Bonn. Coordinate with Walter Brunswig.

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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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