1.1 HOW-TO Visualize observational pointings with
ObsViewer

ObsViewer can query the database for RawScienceFrames or ReducedScienceFrames for a given rectangular region of the sky, wavelength range and range in exposure time. It can output the results in a figure and ascii files.

NOTE1: EXPERIMENTAL VERSION. Bug reports and other feedback welcome: Gijs Verdoes Kleijn (verdoes@astro.rug.nl)
NOTE2: ONLY WFI OBSERVATIONAL POINTINGS ARE QUERIED.

EXAMPLE1 of use at the awe-prompt:

  1. awe> from astro.experimental.ObsViewer import ObsViewer
  2. awe> o=ObsViewer() mathend000#
  3. awe> o.query_database( mathend000#rastart=174, raend=178, decstart=-5, decend=-5,
    ... central_lambdastart=4000.0, central_lambdaend=5000.0,
    ... expomin=0.0, expomax=200.0,raw='yes') mathend000#
  4. awe> o.preview( mathend000#newplot=1,plotcolor='b',plotsize=20) mathend000#
  5. awe> o.plot( mathend000#plotfov=1,fillfov=1,newplot=1,plotcolor='b',plotsize=20,sec_per_dot=1.0) mathend000#

The command lines have the following effects:

  1. IMPORTS MODULE INTO AWE ENVIRONMENT.
  2. MAKES A CLASS INSTANTIATION.
  3. QUERIES THE DATABASE.
    Input parameters:
    • rastart/end: (degrees) start and end right ascension of rectangular region in the sky.
    • decstart/end: (degrees) start and end declination of rectangular region in the sky.
    • central_lambdastart/end: (Angstrom) start and end of wavelength region in which the central wavelength of the exposure filter has to be.
    • expomin/max: (sec) minimum/maximum exposure time for exposure.
    • raw: query for raw images (raw='yes') or reduced images (raw='no').
    Result:
    a query which can be used by o.preview and o.plot.
  4. PLOTS AND SAVES A FIGURE CONTAINING ONLY THE POINTING CENTERS OF THE QUERY RESULTS.
    Input parameters:
    • newplot: make a new plot (newplot=1) or overplot on an existing one (newplot=0)?
    • plotcolor: color of plotting symbol: color='r' means red, and b:blue, g:green, c:cyan, m:magenta, y:yellow, k:black, w:white.
    • plotsize: size of the plotting symbol to plot.
    Output:
    a figure (png format) named ObsViewer_ra_< mathend000#rastart> mathend000#_< mathend000#raend> mathend000#_dec_< mathend000#decstart> mathend000#_< mathend000#decend> mathend000#-_lambda_< mathend000#lambdastart> mathend000#_< mathend000#lambdaend> mathend000#_expo_< mathend000#expomin> mathend000#_< mathend000#expomax> mathend000#_preview.png (see Figure [*]).
    NOTE: the tool buttons on the bottom of the graphical display window can be used to zoom in on parts of the figure.
  5. PLOTS AND SAVES A FIGURE VISUALIZING THE QUERY RESULT AND WRITES AN OUTPUT FILE WITH THE RESULTS.
    Input parameters:
    • plotfov: plot the field of view (FOV) around the pointing centers (0=no, 1=yes)?
    • fillfov: fill the FOV with random poisson points (to emphasize overlapping exposures) (0=no, 1=yes)?
    • sec_per_dot: the number seconds exposure time per dot plot by fillfov. For example, sec_per_dot=10.0 plots a dot for each ten seconds of exposure time.
    • plotcolor: color of plotting symbol: color=rmeans red, and b:blue, g:green, c:cyan, m:magenta, y:yellow, k:black, w:white.
    • plotsize: size of the plotting symbol to plot.
    Outputs:
    A graphical display window with the result.
    A figure (png format) named ObsViewer_ra_< mathend000#rastart> mathend000#_< mathend000#raend> mathend000#_dec_< mathend000#decstart> mathend000#_< mathend000#decend> mathend000#-_lambda_< mathend000#lambdastart> mathend000#_< mathend000#lambdaend> mathend000#_expo_< mathend000#expomin> mathend000#_< mathend000#expomax> mathend000#.png (see Figure [*]). A text file (ascii format) named ObsViewer_ra_< mathend000#rastart> mathend000#_< mathend000#raend> mathend000#_dec_< mathend000#decstart> mathend000#_< mathend000#decend> mathend000#-_lambda_< mathend000#lambdastart> mathend000#_< mathend000#lambdaend> mathend000#_expo_< mathend000#expomin> mathend000#_< mathend000#expomax> mathend000#.txt.
    NOTE: the tool buttons on the bottom of the graphical display window can be used to zoom in on parts of the figure.

EXAMPLE2:

  1. awe> from astro.experimental.ObsViewer import ObsViewer
  2. awe> o=ObsViewer() mathend000#
  3. awe> o.query_database( mathend000#rastart=170, raend=180, decstart=-20, decend=-20,
    ... central_lambdastart=4000.0, central_lambdaend=5000.0,
    ... expomin=0.0, expomax=200.0,raw='yes') mathend000#
  4. awe> o.plot( mathend000#plotfov=1,fillfov=1,newplot=1,plotcolor='b',plotsize=20,sec_per_dot=1.0) mathend000#
  5. awe> o.query_database( mathend000#rastart=170, raend=180, decstart=-20, decend=-20,
    ... central_lambdastart=5000.0, central_lambdaend=6000.0,
    ... expomin=0.0, expomax=200.0,raw='yes') mathend000#
  6. awe> o.plot( mathend000#plotfov=1,fillfov=1,newplot=0,plotcolor='g',plotsize=20,sec_per_dot=1.0) mathend000#

The command lines have the following effects:

  1. -.4: similar to steps in example 1.
  2. Now the query is made for frames with a central_lambda different from step 3
  3. The result from the query in step 5 is overplotted in green on the existing plot from step 4 (see Figure [*]).

Figure: Example output figure from awe> mathend000# o.preview(). The circles indicate the centers of the pointings.
1#1

Figure: Example output figure from awe> mathend000# o.plot(plotfov=1,fillfov=1). The rectangles represent the FOV of the exposure to scale. The random dots (by setting fillfov=1) reflect the exposure time as explained in example 1.
2#2

Figure: Example output figure from two queries as in example 2. The rectangles represent the FOV of the exposure to scale. The random dots (by setting fillfov=1) reflect the exposure time as explained in example 1.
3#3



page generated Tue Apr 4 14:29:40 CEST 2017