tastis

Analyze STIS target acquisition images. tastis will print general information about each input target acquisition image, and will analyze both types of STIS target acquisitions: ACQs and ACQ/PEAKs

ACQ procedure is described in “STIS Onboard CCD Target Acquisitions” in the STIS Instrument Handbook. The ACQ/PEAK procedure is described in “Onboard Target-Acquisition Peakups (ACQ/PEAK)” also in the STIS Instrument Handbook.

Target positions in global and local (subarray) coordinates and the total flux of the target in the maximum checkbox during both acquistions phases (course and fine) are displayed.

If update=True, keywords are added to the header to make problems easier to locate in batch processing. Warnings are given if the spt file is not present when tastis is run.

Examples

tastis with the default of update=False:

>>> import stistools
>>> stistools.tastis.tastis("ocmv0lw6q_raw.fits")
===============================================================================
oc7w11viq       HST/STIS    G430L        0.3X0.05ND             ACQ/PEAK-UP
prop: 13465      visit: 11    line: 3   target: HD128621-2
obs date, time: 2014-07-24    22:05:06   exposure time:  0.10
dom GS/FGS: S7QX000330F1    sub-dom GS/FGS: S7QX000694F2
ACQ params:     bias sub: 1510                     method: RETURN-TO-BRIGHTEST
subarray (axis1,axis2):   size=(1022,32)          corner=(25,500)
-------------------------------------------------------------------------------
Scan type: LINEARAXIS2                  Step size (mas): 250
 [210 753   0]
                    axis1 axis2     axis1  axis2         V2   V3
                      (pixels)        (arcsec)           (arcsec)
Estimated slew:      0.0  -0.1     0.000 -0.005     -0.004  0.004
Flux in post-slew confirmation image (751752) - Pedestal (748587) = 3165 DN
-------------------------------------------------------------------------------
The flux in the confirmation image is 320% greater than the maximum flux
in the ACQ/PEAK scan.  An excess greater than 100% indicates
problems in the ACQ/PEAK.
The flux in the confirmation image is 16% of the recommended minimum
of 20000 DN for a dispersed-light ACQ/PEAK.  The signal-to-noise in
the AC
===============================================================================

tastis with update=True:

>>> import stistools
>>> stistools.tastis.tastis("ocmv0lw6q_raw.fits", update=True)
===============================================================================
ocmv0lw6q       HST/STIS    MIRVIS      F25ND3             ACQ/POINT
prop: 13760      visit: 0L    line: 1   target: CD-59D3300
obs date, time: 2016-09-29    23:43:50   exposure time:  1.10
dom GS/FGS: S4B0000993F2    sub-dom GS/FGS: S4B0000953F1
ACQ params:     bias sub: 1510   checkbox: 3      method: FLUX CENTROID
subarray (axis1,axis2):   size=(100,100)          corner=(487,466)
-------------------------------------------------------------------------------
Coarse locate phase:           Target flux in max checkbox (DN): 1560
                       global          local
                    axis1 axis2     axis1 axis2
Target location:    534.2  507.0    48.2  42.0
                    axis1 axis2     axis1  axis2         V2      V3
                      (pixels)        (arcsec)            (arcsec)
Estimated slew:     -1.5  -9.0    -0.079 -0.457       -0.379  0.268
-------------------------------------------------------------------------------
Fine locate phase:            Target flux in max checkbox (DN): 1559
                       global            local
                    axis1 axis2     axis1 axis2
Target location:    534.2  516.8    48.2  51.8
Ref ap location:    537.5  517.0    19.5  17.0
                    axis1 axis2     axis1  axis2         V2      V3
                      (pixels)        (arcsec)           (arcsec)
Estimated slew:     -2.1  -0.2     -0.104 -0.010      -0.081 -0.067
-------------------------------------------------------------------------------
Total est. slew:    -3.6  -9.2    -0.183 -0.467        -0.460  0.201
-------------------------------------------------------------------------------
Your ACQ appears to have succeeded, as the fluxes in the coarse
and fine stages agree within 25% and the fine slews were less than
4 pixels as expected
===============================================================================
stistools.tastis.tastis(raw_filename, update=False)

Analyze STIS target acquisition images.

Parameters:
raw_filename: str

Name of the input raw file. For some raw files you will need a copy of the spt file in the same directory.

update: bool

If True, keywords associated with tastis checks will be updated. Default values is False.