FINDER

Name

finder

Purpose (one Line Only)

Interactive finder chart tool

Description

This widget tool will allow you to load a FITS image with astrometric
information (format generated by astinfo.pro). From this starting
point it will resample the image to the scale and orientation needed
to match your telescope or instrument system. It has modes to permit
tracking an object as well as controlling orientation for equatorial
or alt-az telescopes (with no de-rotator).
In the main image display window a left click will place the marked at
that position. As you move around the window (without clicking) you
see the coordinates under the cursor and the offset from the current
marker position.
Toolbar functions:

File

Open Image
Browse and find a FITS image to be displayed. Upon sucessfully
loading an image with astrometric information the display is reset
for the current scale and orientation but putting the image center
and marker at the center of this image. Observatory and time
settings are not changed.
Save as PNG
Snapshot of screen image to a png format graphics file. The name is
automatically generated. The first part of the file name is the
observatory string as shown in the widget. Next, the current date
and time is appended. These three fields are separated by "_" and
file suffix is .png.
Exit
Quit program. There is no auto-save of the configuration.
Tools
Set Position Angle
You are prompted for a new position angle for the display. If in
equatorial mode this the position of north on the display measured
clockwise from up. Center and marker positions are not affected.
Toggle Horizon Mode
There are two modes, equatorial and local horizon modes. In equatorial
mode the normal display is north up. in local horizon mode, the
normal display is the zenith direction to be up. Any position
angle in effect is unchanged.
Toggle Image Flip
Change the handedness of the display. The normal display is
sky-normal (with no rotation and equatorial mode, north is up and
east is to the left). This is implemented as an inversion in the
RA axis. That means you cannot control the direction of north with
this control. Use the position angle control instead.
Marker to Center
Shift location of marker to match the current center of the image.
Center On Marker
Shift location of image center to match the current position of the
marker.
Config
Load Configuration
Load and use a configuration setup. See discussion of CONFIG keyword
provided below.
Image Size
Change image size. You will be asked to input two numbers, the x and
y sizes of the image to change to.
Image X Size
Change image X size. You will be asked to input one number for the
new x size of the image.
Image Y Size
Change image Y size. You will be asked to input one number for the
new y size of the image.
Image Scale
Change the image scale to the provided number in arcsec/pixel.
Last Config
Not implemented.

Calling Sequence

finder

Inputs

Optional Input Parameters

Keyword Input Parameters

CONFIG - Name of a configuration file to load on startup. File suffix used
for this is '.fdr'. A configuration file saves the image
display, orientation, scale information, and the observatory
information. At present, the only way to get such a file is to
make it yourself by hand. The format is as follows:
Line 1 - ID line, must say FINDER v1.0 starting at column 1.
Line 2 - observatory code or location enclosed in quotes. An observatory
code is a 3-character string as defined by the Minor Planet
Center or a a manual position where you list the latitude
and longitude of the observatory location. You can provide
this in either sexigesimal notation or decimal degrees
(lat and lon are both in degrees in this case). Direction
from prime meridian and equator is denoted by a letter (not a
sign) -- E for east, W for west, N for north and S for south.
Line 3 - xsize of displayed image. This is limited to be no bigger than
80% of your overall screen size.
Line 4 - ysize of displayed image. This limited to be no bigger than 95%
of your overall screen size.
Line 5 - image scale for displayed image (arcsec/pixel)
Line 6 - Image flip, 0=no, 1=yes
Line 7 - Horizon mode, 0=equatorial, 1=local horizon
Line 8 - position angle (degrees)

Outputs

Keyword Output Parameters

Common Blocks

Side Effects

Restrictions

Procedure

Modification History

2010/06/22, Written by Marc W. Buie, Southwest Research Institute
2010/07/09, MWB, added numerous features
2011/03/21, MWB, fixed some of the control logic related to the marker
tools and added a new "marker to center" tool.
2016/06/02, MWB, converted to usage of astcvt tools, added support for
"standard" WCS supported by Astronomy Users Library
tools. My astrometry information is searched for first,
if not found will try extast.
2016/08/05, MWB, fixed a bug that caused the image to be displayed with the
wrong orientation when in the horizon-lock mode. The
image was actually self-consistent with the labels but
was not the orientation requested.