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CSPIKE-Create calibration spiketrum given spiketrum & standard spectrum

Description:
Given a 'spiketrum' generated by GSPIKE from a table of flux densities at given wavelengths for a particular standard star together with a spectrum of that same object, CSPIKE calc- ulates the instrumental response at the various tabulated points. Note - this routine is intended for standards where the tables give the average measured flux density over a given wavelength range for each point, rather than calculated continuum values. CSPIKE will not accept a spiketrum that has data in magnitude units.

Parameters:
SPIKETRUM
A spiketrum (see HELP FIGARO TECHNIQUES SPIKETRA for details) generated from a table of measured average flux densities over given wavelength ranges versus the central wavelengths. The data should not be in magnitude units.
SPECTRUM
An observed spectrum of the object whose tabulated fluxes were used to generate SPIKETRUM. Note that CSPIKE does not insist on the spectrum's having been scrunched, but things are usually easier if it has been.
OUTPUT
CSPIKE generates a spiketrum whose non-zero values give the instrumental response in "units per counts per second per angstrom", where "units" are the units used by the input spiketrum.

Source comments:
 C S P I K E

 Generates a calibration 'spiketrum', given an observation of
 a standard star and a spiketrum giving the tabulated flux
 values for that star.  The calibration spiketrum has points
 giving the instrumental response calculated at the points
 given by the spikes in the flux spiketrum.  A calibration
 spectrum can then be generated by interpolating between the
 points of the calibration spectrum.

 Command Parameters

 SPIKETRUM     (Character) The tabulated flux spiketrum.  Note:
               this should include the BANDWIDTH data
               object - a spiketrum that does not is probably
               not appropriate for this function.  Also note that
               CSPIKE does not work with data in magnitude units.
 SPECTRUM      (Character) The observation of the standard star.
               Note that this should include an exposure time data
               object.  If it does not, a time of 1 sec will be
               assumed, and the calibration will only be relative.
               Both SPECTRUM and SPIKETRUM should contain an
               AXIS(1) data array, giving the wavelength values.  These
               should normally be exactly the same, although this
               is not essential.
 OUTPUT        (Character) The resulting spiketrum of calibration
               points.

 Command keywords - None

 User variables used - None

                                  KS / CIT 28th May 1984


next up previous 79
Next: CSUB-Subtracts a continuum from 2 dimensional data
Up: Applications in detail
Previous: CSET-Interactively set regions of a spectrum to a constant value

FIGARO A general data reduction system
Starlink User Note 86
Keith Shortridge, Horst Meyerdierks,
Malcolm Currie, Martin Clayton, Jon Lockley,
Anne Charles, Clive Davenhall,
Mark Taylor, Tim Ash, Tim Wilkins, Dave Axon,
John Palmer, Anthony Holloway and
Vito Graffagnino
2004 February 17
E-mail:starlink@jiscmail.ac.uk

Copyright © 2013 Science and Technology Facilities Council