2019A ITC Observation Overheads

The 2019A version of the Gemini Integration Time Calculators (ITCs) gives estimates of the observing overheads for all instruments and modes (except for GSAOI which will be released later). The overheads include the correct number of acquisitions (one for every 2 hours of science), detector readout, telescope offsetting, and time for re-centering of spectroscopic observations when required. These calculations make several assumptions about the observing strategy, so please review your results carefully.

Output for a GMOS long-slit observation with 16 x 10-minute exposures binned 1×2:

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2018B ITC Improvements

The 2018B Integration Time Calculator (ITC) includes many improvements:
– Support for summing GMOS IFU elements with an aperture (see figure below)
– Automatically set the GSAOI Strehl in the web form
– Relabel obsolete components as “Unavailable” (while retaining functionality)
– Fix some NIRI filters with unnecessarily wide profiles
– Fix the GMOS nod & shuffle exposure time passed to the ITC from the OT
– Fix a problem causing occasional failures with the power-law input SED
– Fix failures with large user-supplied SEDs
– Remove unnecessary wavefront sensor options
– General cleanup of the web form

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Revert Changes

The old OT has a way to “undo” mistakes by deleting the local copy of your program and re-downloading the previous version from the Gemini database. However, this is not obvious and the process is not intuitive. The new 2018B OT solves this by adding a “Revert Changes…” option to the “File” menu. This will re-download your program from the Gemini database, thereby reverting all your changes since the last time you clicked the “Sync” button. Note that if anybody else has made changes to your program and uploaded them to Gemini the “Revert Changes…” option will also pull in those changes since the program is being downloaded from the database. After selecting “Revert Changes…” the OT will ask for a final confirmation in the form of a pop-up:

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2018B Observing Tool

The 2018B Observing Tool (OT) to be released at the end of May features a 5 micron “lucky” image mosaic of Jupiter taken with NIRI on the Gemini North telescope.  See the press release for more details.

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2018A OT Elevation Plot

The 2018 OT Elevation Plot has been updated so that the light-gray area indicates the time between sunrise/sunset and 12° twilight.  This is a change from previous versions where light-gray indicated the time between 12° and 18° twilights.  This new shading matches the (internal) Gemini observing plans, and the various times are also now labeled in the plot for clarity.

Elevation Plot

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2018A ITC Improvements

The 2018A ITC includes many improvements:
– Add support for GMOS IFU-2 mode with the new Hamamatsu CCDs
– Add support for GNIRS spectroscopy with Altair
– Update the Gemini telescope mirror reflectivity
– Show the SED brightness normalization of user-defined SEDs in the web output
– Display the GMOS peak counts as a fraction of the saturation limit
– Fix the emission line minimum width when the source has a non-zero redshift
– Fix a bug with GNIRS XD + 111 l/mm grating which caused the ITC to fail if the central wavelength was not in the K-band
– Fix the missing TReCS ZnSe cryostat window data file


Posted in 2017 December Release, ITC | Comments Off on 2018A ITC Improvements

Disabling Automatic Guide Star Search


The 2018A OT makes it easier to disable the Automatic Guide Star (AGS) selection, useful for example, for unguided non-sidereal observations.  Either set the Auto Guide Search to “Off” (as shown above), or just delete the automatically selected guide star in the Target component.   AGS may be re-activated by setting the Auto Guide Search back to any valid wave front sensor.

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New Target Types

The 2018A OT includes several new target types to facilitate planning your Gemini observations.  Previously the only target types available were the “Base” (the pointing center), the guide star (OIWFS, PWFSn, or AOWFS), and a single “User” target for all other targets.  The new OT includes 3 additional user-defined targets:

Target Types

1. “Blind Offset” targets for specifying the reference object for a blind offset acquisition

2.  “Off-Axis” targets for defining targets that are not at the base position (for example a two-target acquisition where the “Base” is in between two “off-axis” targets).

3. “Tuning Star” targets for defining the LGS tuning star for  open-loop LGS observations.

Posted in 2017 December Release, Observing Tool | Comments Off on New Target Types

2018A Observing Tool

The 2018A Observing Tool (OT) to be released in December features an image of the interacting galaxy pair NGC 1531 and NGC 1532 imaged with the Gemini Multi-Object Spectrograph (GMOS) on the Gemini South telescope. See the Gemini Image Gallery for more details about the image.

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Timing Widow Import

The 2017B OT supports importing observation timing windows as a text file.  For example:

# Start (UT)           Duration  Repetitions  Period
# yyyy-mm-dd hh:mm:ss  hh:mm     ####         hh:mm:ss

# Windows from 10-11 UT for the entire month of July:
2017-07-01 10:00:00   01:00     31           24:00:00

# One-time window for anytime on July 15:
2017-07-15 00:00:00   24:00

# Window open forever starting at 10 UT on August 1:
2017-08-01 10:00:00  00:00

# Notes:
# 1. Duration = 0 indicates forever.
# 2. Repetitions = -1 indicates infinite repetitions.

Loading this file with the import button () below the Timing Windows table yields:

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