E-ELT Imaging Exposure Time Calculator

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Important Notes

Note: These tools are provided for the technical assessment of feasibility of the observations and instrument configurations only.

See also: Frequently Asked Questions

General description

There are two E-ELT ETCs: Imaging and Spectroscopy. Both are generic Exposure Time Calculators, which can be used to simulate different instrument setups. The interface allows to set the simulation parameters and examine interactively the model generated graphs. The ETC programs allow easy comparison of the different options relevant to an observing program and instrument development, including target information, instrument configuration, variable atmospheric conditions and observing parameters.

These programs provide an HTML/Java based interface and consist of two pages. The observation parameters page presents the entry fields and widgets for the target information, expected atmospheric conditions, instrument configuration, observation parameters such as exposure time or signal-to-noise, and output selection. An "Apply" button submits the parameters to the model executed on the ESO Web server. The results page presents the computed results, including number of counts for the object and the sky, signal-to-noise ratios, instrument efficiencies, PSF size etc..

The optional graphs are displayed within Java applets allowing interactive manipulation. The results are also provided in ASCII and GIF formats for further analysis and printing. Finally a summary of the input parameters is appended to the result page.

Documentation

Please refer to these PDF documents:

Version Information

Version 2.14 (June 17, 2009)
AO mode labels changed (LTAO / MCAO).
Version 2.13 (November 10, 2008)
Bug fix in the imaging ETC: The conversion from AB magnitudes was wrong in the imaging ETC version 2.12.
Version 2.12 (October, 2008)
The target brightness can now be given as Vega mags, AB mags or as a flux in mJy.
Documentation is now exclusively found in the detailled PDF documents.
Version 2.11 (September 12, 2008)
Links to the E-ELT ETCs are now revealed in the table on the main ESO ETC web page.
Version 2.11WG (June 6, 2008)
Imaging: MIR bands (LMNQ) now supported.
Spectroscopy: The S/N is now computed per resolution element Δλ=2pixels.
Spectroscopy: Background model: Emissivities, temperatures and continuum contribution updated.
Documentation updated.
Version 2.10WG (May 15, 2008)
Detector parameters updated. They now depend on the wavelength regime (Optical/NIR/MIR).
Central obstruction area ratio reduced to 8%.
List of MARCS spectra updated.
Documentation updated.
Version 2.9WG (March 10, 2008)
Added support for 5x5 and 10x10 reference areas.
Documentation updated.
Cosmetic corrections.
Version 2.8WG (February 5, 2008)
Imaging and Spectroscopy are now supported by different models.
This document refers to imaging only. For spectroscopy, please refer to the detailed description document.
Version 2.7WG (October 17, 2007)
Tables with AO performance data updated.
Documentation updated.
Version 2.6WG (September 24, 2007)
Tables with AO performance data updated.
Documentation updated.
Version 2.5WG (March 9, 2007)
Spectroscopy only: The object and sky signals are consistently integrated over 2 spectral pixels (one resolution element).
Documentation updated.