NOAO Web Observing Proposal - Targets

NOAO Web Observing Proposal

Targets


Target tables are specially formatted tables available through the Web form ("Enter Tables" button) and/or through the LaTeX template. These tables are required for all Gemini runs, and for any queue or service runs on other telescopes

The format of the target tables is the same for all telescopes/instruments except for Gemini which has its own requirements and specifications. The remaining sections of this document deal with these target tables explicitely.

Information requested in target tables

The fields in the non-Gemini target tables include:

  Object ID            queue: specify a unique 3-digit number for each target
  Object               20 characters maximum
  RA                   e.g., xx:xx:xx.x
  DEC                  e.g., +-xx:xx:xx.x
  Epoch                e.g., 1950.3
  Magnitude 
  Filter 
  Exposure time        in seconds PER EXPOSURE
  Number of exposures
  Days from new moon   use a number 0-14
  Sky condition        use "spec" or "phot"
  Seeing               max allowable PSF FWHM (arcsecs)
  Comment              20 characters maximum
The fields in the Gemini target tables include:
  Object ID        unique 4-digit number assigned automatically
  Object           20 characters maximum
  RA               e.g., xx:xx:xx.x
  DEC              e.g., +-xx:xx:xx.x
  Epoch            all targets must be B1950 or J2000
  Magnitude
  Observation time total exposure time and overhead in minutes for all filters
  Image quality    these next 4 parameters are given as percentages as described at
  Cloud cover       http://www.us-gemini.noao.edu/sciops/ObsProcess/obsConstraints/obsConstraints.html
  Water vapor        
  Sky background
  Guidestars       P=PWFS, 0=OIWFS, A=AOWFS, lower case=marginal selection (no longer found in phase I)
  Comment          20 characters maximum

Entering targets

Targets for Gemini must be entered through the Web form - do not attempt to add targets to the LaTeX template. Target tables for other telescopes/instruments may be entered through the Web form or the LaTeX template.

Each target table generated through the Web form is restricted to 50 targets, but each run can have multiple target tables.

Targets can be typed directly into the target table or a list of targets can be uploaded through the Web form using an ASCII-formatted file. The uploaded file contains the target name (20 characters max.), epoch (only B1950 or J2000 allowed for Gemini), and the RA and DEC (+-xx:xx:xx.x) in a tab-separated list. For example:

NGC 4151	B1950	12:08:01.1	39:41:02
NGC 7027	B1950	21:05:09	42:02:03
L183	B1950	15:51:35.7	-02:40:54
Once the targets have been uploaded into the target table the user can edit the table entering the remaining required information.

Computing exposure times and overhead

Each of the telescopes/instruments that require target tables asks for exposure time estimates in the target table. How the exposure times are computed vary with the telescope/instrument requested so please review this information carefully for each run before completing the target tables. The times should be in units of seconds except for Gemini where minutes are required.

For Gemini, the observing time should be the total wall-clock time (in minutes) needed to observe your target. This must include the sum of all exposure times in all filters plus overhead. Do not simply enter the time returned from an exposure time calculator as this will not include overhead for target and guide star acquisition, which will typically be an additional 15-30 minutes per pointing. Offsetting for sky exposures and dithering will also add to the total observation time. In most cases, summing the observation times for all targets should very nearly equal the total time request from the front page of your proposal. It can be very helpful to reviewers if you include a specific breakdown of your time request in the body of your technical description.

The Gemini Observatory website provides information on the performance of these instruments which can be used to estimate integration times and overhead. This can be found in the "Performance and Use" sections of their web documentation.

Gemini maintains Integration Time Calculators for its facility instruments at

http://www.gemini.edu/sciops/instruments/integration-time-calculators

Gemini observing condition constraints

The minimal acceptable constraints on observing conditions (image quality, sky brightness, water vapor, and cloud cover) must be specified for Gemini targets. These constraints are specified according to the percentile of time the conditions are matched or exceeded. So, selecting "20" indicates that you need conditions for that constraint that occur only 20% of the time. If you also select "20" for another non-correlated constraint, you would essentially be requesting conditions that occur just 4% (20% x 20%) of the time (assuming the other constraints are set to "any"). To optimize the chance that your program can be carried out, select the most generous limits you can for your observations.

For details on the specific conditions associated with percentiles for each condition, see the Gemini observatory web page at

http://www.gemini.edu/sciops/telescopes-and-sites/observing-condition-constraints