Observing Tools

Contents:

A main driver function is makeAnnualChart()

observing.dms(d, delim=':', output_string=False)

Convert degrees, minutes, seconds to decimal degrees, and back.

EXAMPLES:

dms(‘150:15:32.8’) dms([7, 49]) dms(18.235097) dms(18.235097, output_string=True)

Also works for negative values.

SEE ALSO: hms()

observing.drawAnnualChart(dates, hrs, visibility, title='', fs=16, dt=0)

Draw charts computed by makeAnnualChart().

INPUTS:

dates, hrs, visibility

Inputs suitable for pylab.contourf(dates, hrs, visibility)

fs : scalar

Font size

observing.hms(d, delim=':', output_string=False)

Convert hours, minutes, seconds to decimal degrees, and back.

EXAMPLES:

hms(‘15:15:32.8’) hms([7, 49]) hms(18.235097) hms(18.235097, output_string=True)

Also works for negative values.

SEE ALSO: dms()

observing.isNumeric(input)

Simple test for whether input is numeric or not.

observing.isObservable(dates, obs, target, minElevation=30, twilight=12, oversamp=16)

True if pyEphem object ‘target’ is visible to observer ‘obs’ on the input ‘dates’; False otherwise.

observing.makeAnnualChart(obs, ra, dec, minElevation=30, twilight=12, oversamp=16, dt=0)

Make pretty plots of target visibility during the year. E.g., to observe the Kepler field from Keck:

(Source code, png, hires.png, pdf)

INPUTS:

obs : str

‘lick’ or ‘keck’ or ‘lapalma’ or ‘mtgraham’ or ‘mtbigelow’ or

‘andersonmesa’ or ‘kpno’ or ‘ctio’ or ‘cerropachon’ or ‘palomar’ or ‘cerroparanal’ or ‘lasilla’ or ‘calaralto’ or ‘lascampanas’ (cf. setupObservatory())

minElevation : float

Minimum visible elevation angle. ‘30’ implies airmass=2.

twilight : float

Minimum acceptable angular distance of sun below horizon, in degrees.

dt : scalar

Timezone offset from UTC. Positive for east, negative for West.

EXAMPLE:

import observing as obs

# Plot Visibility of the Kepler Field:
obs.makeAnnualChart('keck', '19:22:40', '+44:30:00', dt=-10)
obs.makeAnnualChart('mtgraham', '19:22:40', '+44:30:00', dt=-7)

NOTES:

Based on the attractive plots used by the California Planet Search team.

observing.setupObservatory(obs, lat=None, long=None, elevation=None)

Set up PyEphem ‘observer’ object for a given observatory.

INPUTS:

obs : str

Name of an observatory. ‘lick’ or ‘keck’ or ‘lapalma’ or ‘mtgraham’ or ‘mtbigelow’ or ‘andersonmesa’ or ‘kpno’ or ‘ctio’ or ‘cerropachon’ or ‘palomar’ or ‘cerroparanal’ or ‘lasilla’ or ‘calaralto’ or ‘lascampanas’ or ‘saao’ or ‘sidingspring’

observing.setupTarget(ra_deg, dec_deg, pmra=0, pmdec=0, name=None, verbose=False)

ra_deg, dec_deg : strings or scalars

Right ascenscion and Declination, in decimal degrees (scalar) or sexagesimal (if strings)