Observability Plots (ligo-skymap-plot-observability)

This is similar to ligo-skymap-plot-airmass, but integrated over the sky in order to create a bar chart and show the observability windows for several facilities at once.


To make an observability plot for GW170817:

$ curl -O https://dcc.ligo.org/public/0146/G1701985/001/bayestar.fits.gz
$ ligo-skymap-plot-observability --site 'Las Campanas Observatory' 'SAAO' 'Siding Spring Observatory' --time 2017-08-17 bayestar.fits.gz -o bayestar.png

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


Make an observability chart for a LIGO/Virgo probability sky map.

usage: ligo-skymap-plot-observability [-h] [-o FILE.{pdf,png}]
                                      [--colormap CMAP] [--help-colormap]
                                      [--figure-width INCHES]
                                      [--figure-height INCHES] [--dpi PIXELS]
                                      [--transparent [TRANSPARENT]]
                                      [-l CRITICAL|ERROR|WARNING|INFO|DEBUG|NOTSET]
                                      [-v] [--time TIME]
                                      [--max-airmass MAX_AIRMASS]
                                      [--twilight {astronomical,nautical,civil}]
                                      [--site [SITE [SITE ...]]] [--help-site]
                                      [--site-name [SITE_NAME [SITE_NAME ...]]]
                                      [--site-longitude [DEG [DEG ...]]]
                                      [--site-latitude [DEG [DEG ...]]]
                                      [--site-height [METERS [METERS ...]]]

Positional Arguments


Input FITS file

Default: -

Named Arguments


show program’s version number and exit

-l, --loglevel

Default: INFO

-v, --verbose

Print airmass table to stdout

Default: False


UTC time


Maximum airmass

Default: 2.5


Possible choices: astronomical, nautical, civil

Twilight definition: astronomical (-18 degrees), nautical (-12 degrees), or civil (-6 degrees)

Default: “astronomical”


Possible choices: , , , A1, ACIGA, ALLEGRO_320, ALMA, ATST, AURIGA, Anglo-Australian Observatory, Apache Point, Apache Point Observatory, Atacama Large Millimeter Array, B1, BAO, BBSO, Beijing XingLong Observatory, Black Moshannon Observatory, C1, CHARA, CIT_40, Canada-France-Hawaii Telescope, Catalina Observatory, Cerro Pachon, Cerro Paranal, Cerro Tololo, Cerro Tololo Interamerican Observatory, DCT, DKIST, Discovery Channel Telescope, Dominion Astrophysical Observatory, E0, E1, E2, E3, ET0_T1400308, ET1_T1400308, ET2_T1400308, ET3_T1400308, EXPLORER, G1, GBT, GEO_600, Gemini South, Green Bank Telescope, H1, H2, Hale Telescope, Haleakala Observatories, Happy Jack, I1, IAO, JCMT, James Clerk Maxwell Telescope, Jansky Very Large Array, K1, KAGRA, Keck Observatory, Kitt Peak, Kitt Peak National Observatory, L1, LHO_2k, LHO_4k, LIO_4k, LLO_4k, La Silla Observatory, Large Binocular Telescope, Las Campanas Observatory, Lick Observatory, Lowell Observatory, MWA, Manastash Ridge Observatory, McDonald Observatory, Medicina, Medicina Dish, Michigan-Dartmouth-MIT Observatory, Mount Graham International Observatory, Mt Graham, Mt. Ekar 182 cm. Telescope, Mt. Stromlo Observatory, Multiple Mirror Telescope, Murchison Widefield Array, N1, NIOBE, NOV, NST, National Observatory of Venezuela, Nautilus, Noto, O1, Observatorio Astronomico Nacional, San Pedro Martir, Observatorio Astronomico Nacional, Tonantzintla, Palomar, Paranal Observatory, Roque de los Muchachos, SAAO, SALT, SPO, SRT, Sac Peak, Sacramento Peak, Siding Spring Observatory, Southern African Large Telescope, Subaru, Subaru Telescope, Sunspot, Sutherland, T1, TAMA_300, TUG, U1, UKIRT, United Kingdom Infrared Telescope, V0, V1, VIRGO, VIRGO_CITF, Vainu Bappu Observatory, Very Large Array, W. M. Keck Observatory, Whipple, Whipple Observatory, X1, aao, alma, apo, bbso, bmo, cfht, ctio, dao, dct, dkist, ekar, example_site, flwo, gbt, gemini_north, gemini_south, gemn, gems, greenwich, haleakala, iao, irtf, jcmt, keck, kpno, lapalma, lasilla, lbt, lco, lick, lowell, mcdonald, mdm, medicina, mmt, mro, mso, mtbigelow, mwa, mwo, noto, ohp, paranal, salt, sirene, spm, spo, srt, sso, tona, tug, ukirt, vbo, vla

Observatory site

Default: []


show supported values for –site and exit


Observatory name.

Default: []


Observatory longitude on the WGS84 ellipsoid.

Default: []


Observatory latitude on the WGS84 ellipsoid.

Default: []


Observatory height from the WGS84 ellipsoid.

Default: []

figure options

Options that affect figure output format

-o, --output

output file, or - to plot to screen

Default: -


Possible choices: Accent, Accent_r, Blues, Blues_r, BrBG, BrBG_r, BuGn, BuGn_r, BuPu, BuPu_r, CMRmap, CMRmap_r, Dark2, Dark2_r, GnBu, GnBu_r, Greens, Greens_r, Greys, Greys_r, OrRd, OrRd_r, Oranges, Oranges_r, PRGn, PRGn_r, Paired, Paired_r, Pastel1, Pastel1_r, Pastel2, Pastel2_r, PiYG, PiYG_r, PuBu, PuBuGn, PuBuGn_r, PuBu_r, PuOr, PuOr_r, PuRd, PuRd_r, Purples, Purples_r, RdBu, RdBu_r, RdGy, RdGy_r, RdPu, RdPu_r, RdYlBu, RdYlBu_r, RdYlGn, RdYlGn_r, Reds, Reds_r, Set1, Set1_r, Set2, Set2_r, Set3, Set3_r, Spectral, Spectral_r, Wistia, Wistia_r, YlGn, YlGnBu, YlGnBu_r, YlGn_r, YlOrBr, YlOrBr_r, YlOrRd, YlOrRd_r, afmhot, afmhot_r, autumn, autumn_r, binary, binary_r, bone, bone_r, brg, brg_r, bwr, bwr_r, cividis, cividis_r, cool, cool_r, coolwarm, coolwarm_r, copper, copper_r, cubehelix, cubehelix_r, cylon, cylon_r, flag, flag_r, gist_earth, gist_earth_r, gist_gray, gist_gray_r, gist_heat, gist_heat_r, gist_ncar, gist_ncar_r, gist_rainbow, gist_rainbow_r, gist_stern, gist_stern_r, gist_yarg, gist_yarg_r, gnuplot, gnuplot2, gnuplot2_r, gnuplot_r, gray, gray_r, hot, hot_r, hsv, hsv_r, inferno, inferno_r, jet, jet_r, magma, magma_r, nipy_spectral, nipy_spectral_r, ocean, ocean_r, pink, pink_r, plasma, plasma_r, prism, prism_r, rainbow, rainbow_r, seismic, seismic_r, spring, spring_r, summer, summer_r, tab10, tab10_r, tab20, tab20_r, tab20b, tab20b_r, tab20c, tab20c_r, terrain, terrain_r, turbo, turbo_r, twilight, twilight_r, twilight_shifted, twilight_shifted_r, viridis, viridis_r, winter, winter_r

matplotlib colormap

Default: cylon


show supported values for –colormap and exit


width of figure in inches

Default: 8


height of figure in inches

Default: 6


resolution of figure in dots per inch

Default: 300


Save image with transparent background

Default: 0