Change page style: 

NIRI Update: guiding issues for NIRI during 2003A

31 Jan 2003

NIRI has been working well recently. NIRI queue observing is scheduled to start 13 Feb 2003. Phase II proposals should be sent to the national project offices for checking as soon as possible (see the 2003A special instructions for deadlines and submission details).

Peripheral wavefront sensor #1 (PWFS1) had a mechanical problem recently and was removed from the telescope for repairs and optical adjustment. Phase II proposals should therefore not request PWFS1 until further notice.

NIRI Update: results from semester 2003A

19 Jun 2003

We recently completed the last scheduled NIRI observing block for semester 2003A. The weather cooperated and we consistently achieved 0.3 arcsec images using PWFS2. We were able to complete about 90% of the queue Band 1 observations.

Phase II Checklist


  • Are observations defined for all targets and for all grating settings (if more than one requested)?

Phase I Checklist

Instrument configuration:

  • Is the appropriate order sorting filter for each desired spectral interval specified in the proposal instrument resource list? 
  • Does your choice of slit give appropriate spectral resolution and sensitivity?

Telescope peripheral wavefront sensors:

  • Have you specified one guide star of adequate brightness for the peripheral wavefront sensor?

Phoenix OT Details

After the queue for a given semester is consolidated, the PIs of approved proposals will be sent a "Phase II skeleton", which is imported in to the Observing Tool (OT) so that individual observations can be defined, by selecting each one at a time.

Phoenix OT layout

Transmission Spectrum

A 0.9-5.6µm model transmission spectrum of the atmosphere over Cerro Pachon is available (as a 4.9MB text file) here. The spectrum is for an airmass of 1.5 and for 7.6 mm of water (thus somewhat non-optimal conditions at wavelengths where H2O is important). The resolution is 0.00004µm, roughly comparable to the resolution of Phoenix (somewhat lower near 1µm and somewhat higher near 5µm. The wavelength scale is in vacuo.


All Observers

The overhead for slew and set-up is usually 20 minutes. Acquisition of the target consists of images, offsets and instrument configuration changes, all of which are done manually by the observer on the dedicated Phoenix computer.

The following overheads must also be included in the time requested for each scientific observation.

Phoenix ITC

NOAO's exposure time calculator for Phoenix can be used to roughly estimate the Phoenix sensitivity, but it is particularly inaccurate in the 3-5 micron region. For actual measurements see the Sensitivity Table or the Sensitivity Plots.