SCUBA-2 Integration Time Calculator

Introduction

This package contains the Python-based integration time calculator for SCUBA-2. It is based on the original Perl Astro::ITC::SCUBA2 module.

Usage

The integration time calculator (ITC) can be used in a Python program via a SCUBA2ITC object. The main calculation methods are calculate_total_time and calculate_rms_for_total_time. Each of these takes an optional with_extra_output argument. If this is not specified, only the main answer is returned, but if a true value is given, a (result, extra) pair is returned, where extra is a dictionary of supplemental information.

Sampling factors are given relative to the default pixel sizes of 4" and 2" at 850um and 450um respectively. For more information, see the SCUBA-2 sensitivity page.

Here is an example time calculation for a 1800" pong observation:

from jcmt_itc_scuba2 import SCUBA2ITC, SCUBA2ITCError

itc = SCUBA2ITC()

try:
    airmass = itc.estimate_airmass(declination_deg=20.0)

    sampling_factors = {
        850: (6.5 / 4) ** 2,
        450: (4 / 2) ** 2 }

    (result, extra) = itc.calculate_total_time(
        mode='pong1800',
        filter_=850,
        tau_225=0.065,
        airmass=airmass,
        sampling_factors=sampling_factors,
        rms=5.0,  # Jy/beam
        with_extra_output=True)

    print('Main result: {}'.format(result))
    print('Extra information: {!r}'.format(extra))

except SCUBA2ITCError as e:
    print('Error: {}'.format(e))

License

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>