Differences between revisions 41 and 43 (spanning 2 versions)
⇤ ← Revision 41 as of 2006-01-09 16:54:25 →
Size: 6806
Editor: AlbrechtSievers
Comment:
← Revision 43 as of 2006-02-10 13:05:41 → ⇥
Size: 6416
Editor: HansUngerechts
Comment:
Deletions are marked like this. Additions are marked like this.
Line 42: Line 42:
/!\ Raw data processing software for heterodyne (MIRA) has to be run manually. (Will be automatic as soon as possible!) /!\ A prototype of automatic processing of heterodyne data using the MIRA software is available. Its features will be expanded as soon as possible. MIRA can also be run manually and offline. (2006-02 HU)
Line 62: Line 63:
heterodyne: OK, but could be improved (last model update: 2005-11). heterodyne: OK, (last model update: 2006-01-30 15:16).
Line 64: Line 65:
bolometer: OK, but could be improved (last model update: 2005-11).

/!\ Occasional pointing problems continue to be reported. In order to investigate this, see the next comment!

/!\ Operator/AOD: Check regularly that secondary/ spindle control, weather data for refraction correction, and automatic P4/P5 are working correctly -- if necessary ask a member of the NCS team for instructions about this (2005-12).		 bolometer: OK, (last model update: 2006-02-09 08:35).
Line 86: Line 83:
/!\ HERA is not yet supported by NCS. (to be done for 2006, February). (./) HERA is supported by the NCS. (2006-02 HU)
Line 111: Line 108:
computed by MIRA (2006-01-09, AS). computed by MIRA. In addition MIRA seems not to subtract a baseline, so the results
are mostly useless (2006-01-09, AS).
Line 117: Line 115:
/!\ HERA is not yet supported by NCS. To be done for 2006-02. (./) HERA is supported by the NCS. (2006-02 HU)
Line 127: Line 125:
/!\ When using HERA 1 and 2 configure only 1 Channel for continuum observations in OBS, never-the-less the continuum drifts of all channels are reduced (calibrated) by ODP [AS 11.10.2005]
Line 145: Line 143:
 * /!\ WILMA not yet supported by NCS  * (./) WILMA is supported by NCS for observations with HERA (2006-02 HU)

Anchor(beginOfPage)

TableOfContents(3)

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)

NCS supports observing modes and source offsets in:

  • Projection "Radio" (same offsets as in old CS) in Equatorial J2000.0
  • "true angle" horizontal
  • Nasmyth (receiver offsets)

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

Observing modes supported by the NCS:

  • Calibrate (for heterodyne)
  • Pointing
  • Focus
  • Tip (for bolometer)
  • Track (Frequency Switching)
  • ON-OFF (Position Switching or Wobbler Switching)
  • On-The-Fly Map
  • VLBI

/!\ A prototype of automatic processing of heterodyne data using the MIRA software is available. Its features will be expanded as soon as possible. MIRA can also be run manually and offline. (2006-02 HU)

[#beginOfPage Back to top]

Antenna

(./) OK

[#beginOfPage Back to top]

Wobbler

Available under NCS.

/!\ Wobbler rotation (actually, secondary rotation) not yet available under NCS.

[#beginOfPage Back to top]

Pointing Model

heterodyne: OK, (last model update: 2006-01-30 15:16).

bolometer: OK, (last model update: 2006-02-09 08:35).

/!\ Pointing on spectral line sources like SiO masers is not available.

[#beginOfPage Back to top]

SIS Receivers

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

/!\ Some problems reported from B100: difficult to lock/tune at some frequencies, higher Trx, ...

/!\ Image/Signal gain-ratio calibration is not yet supported by NCS.

(./) Standard table of T_cold calibration temperatures (same as in old CS) is implemented in NCS; note that this covers only a limited standard range of frequencies. /!\ Outside this range, T_cold has to be set manually.

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

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

[#beginOfPage Back to top]

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 then others in this respect as summarized here:

  • A100 generally OK for pointing. (2003-11-12) BR B100 OK, is best for pointing. BR /!\ C150 often bad for pointing, ripple. (2002-07-16) BR D150 generally good performance for pointing.(2002-07-16) BR /!\ A230 often unstable, bad for pointing and flux monitoring. (2003-11-12) BR B230 OK BR /!\ C270 very bad for pointing at 265 Ghz. (2002-07-16) BR /!\ D270 can be unstable and difficult for pointing. (2002-07-16) BR

    HERA pointing difficulties using beam switch mode - total power mode gave better results but requires excellent weather BR Wobbler switching may avoid ripple, beam switching is most sensitive to ripple

/!\ Beam Switch is broken, when using wobbler switching, MIRA gives wrong pointing corrections, use SET POINTING dAzm+beamthrow/2 dElv, where dAzm, dElv are the values computed by MIRA. In addition MIRA seems not to subtract a baseline, so the results are mostly useless (2006-01-09, AS).

[#beginOfPage Back to top]

HERA

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

Second polarization installed. /!\ One blind pixel. BR SSB tuning tables for standard frequencies. BR Sideband rejections not determined (2004-12-01 AW) BR

/!\ 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 /!\ With VESPA, the maximum of 4 spectra per pixel can be used. BR /!\ /!\ Much higher noise in HERA 2 than HERA 1 when using Vespa. This is being investigated by S. Navarro [RM 30.6.2005]BR

[#beginOfPage Back to top]

Bolometers

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

[#beginOfPage Back to top]

Backends

Support by NCS:

  • (./) Continuum Backends for single-pixel heterodyne receivers

  • (./) 4 MHz Filterbanks

  • (./) 1 MHz Filterbank in parts of 256, 512, 768, or 1024 channels; /!\ without frequency shifts.

  • /!\ 100 kHz Filterbank not yet supported by NCS

  • (./) WILMA is supported by NCS for observations with HERA (2006-02 HU)

  • (./) VESPA

[#beginOfPage Back to top]

Computer/Software

/!\ The 30-m telescope is now operating using the New Control System (NCS) (2005-11-30 HU). Note that the NCS so far supports only a restricted set of features!

/!\ Raw data processing software for heterodyne (MIRA) has to be run manually. (Will be automatic as soon as possible!)

[#beginOfPage Back to top]

Other Items

OK

[#beginOfPage Back to top]

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.

[#beginOfPage Back to top]

Legend

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

The wiki markup of these icons is:

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

[#beginOfPage Back to top]

TelescopeSystemStatus (last edited 2025-01-25 17:12:49 by msanchez)