hg_patch extracts a rectangular
[Section 1. Programs, DRMS Modules, Shell Scripts]

hg_patch extracts a rectangular heliographic region or patch from an input series. The patch is tracked across the solar disk from t_start to t_stop times. The patch may be defined by Carrington coordinates or in arcsec. The extracted patch is rectangular in original image pixels. More...

Collaboration diagram for hg_patch extracts a rectangular:

region or patch from an input series. The patch is tracked across the solar disk from time t_start to t_stop. The patch is defined by either its Carrington rotation, longitude, latitude and size when it crosses central meridian or by its location in arcsec at a reference time. If defined by Carrington coordinates the bounding box size is specified in degrees of longitude and latitude at disk center. If the box is specified by its reference image time and location in arcsec from disk center, its size is also specified in arcsec.

Written by: Bala Poduval as extract_region, modified by Phil Scherrer

Synopsis:

   hg_patch in=<recordset> out=<series_out>  \
   log=<logfile> \
   t_start=<start time> \
   t_stop=<end time> \
   cadence=<step time> \
   car_rot=<Carrington Rotation> \
   t_ref=<ref_time> \
   locunits=<location units> \
   x=<ew location> \
   y=<ns location> \
   boxunits= <patch spec units> \
   height=<height> \
   width=<width> \
   requestid=<RequestID> \
   [-t] \

Cadence is the desired time between extracted frames. It will be modified to be a multiple of the dataset's step size. The extracted region location may be specified by position at a reference time or by Carrington coordinates. The position may be specified in arcsec or Stonyhurst coordinates. If the car_rot parameter is specified, the Carrington location method is used. If the t_ref parameter is present, location is specified by a method given in <locunits>. The location is given in the "x" and "y" arguments where the units of x and y are determined by locunits. The choices for locunits are: "arcsec", "pixels", "stony", "carrlong". For "stony" (Stonyhurst) x is the CM distance in degrees, for "carrlong" x is Carrington longitude. The y value is in degrees for either "stony" or "carrlong". locunits can be "arcsec" or "stony".

The size of the patch, given in the width and height parameters can be expressed in "pixels", "arcsec", or "degrees" as determined by the "boxunits" parameter.

If the logfile is present, a RecordSet query will be written to it for each image created containing a query that will returnthat image.

RequestID, if present, is the ID of an on-requst processing export request.

If t_start or t_stop are not present, those values will be inferred from the on-disk time span for the center of the patch -90 degrees to +90 degrees from CM. If cadence is not specified, the full cadence of the dataset will be used. This module computes the beginning and ending time for tracking the region identified at time = t_ref, x and y or by the Carrington coordinates of the box center. In the Carrington case the module extracts a rectangular region with user defined size. the height and width of the box are specified in degrees of latitude and longitude with the pixel size of the box is computed from the projection of the box at CM. The pixel size of the rectangular box remains constant during tracking. The box height defaults to the width. The width defaults to 10 degrees.

If the input recordset spec is exactly "[$]" it will be discarded and the time limits will be taken from t_start, t_stop, car_rot, and/or t_ref as appropriate. This is to allow exports via jsoc_fetch to not require a bounding recordset to be specified.

If t_start and/or t_stop are specified the referecne time or disk center location might be not included.

If the input is only a seriesname, it must have a prime key of type time.

If the t_ref parameter is specified, there must be a non-missing image within +- 2 hours of t_ref.

The output seriesname defaults to the input seriesname with a suffix of "_hgpatch".

The -t, 'no tracking' flag casues the extracted region to remain fixed with respect to disc center. I.e. the Carrington tracking is disabled. The center of the extract region must be on the disk.

Flags:

-t Disable tracking.

GEN_FLAGS:

Ubiquitous flags present in every module. DRMS common main program

Parameters:

	in	The input data series.
	out	The output series.

Exit_Status:

Example:

Extracts a rectangular region of size 20 x 10 degrees and tracks it from when the region is just appearing at the E-limb to t_stop.

   hg_patch in='mdi.fd_M_96m_lev18' out='su_bala.extractreg' locunits=carrlong boxunits=pixels car_rot=2009 x=295 y=5 width=30 height=20

Example:

Bug:

No doubt some bugs.