Data Wizard
Creating TPoint Mapping Data TheSky6
You can use
TheSky6's
Tools | "Map Points" to easily create a set of
Earth based altitude and azimuth mapping points. These points will then
automatically be slewed to then mapped by performing an astrometric solution on
the image. The accuracy of the mapping is determined by your scale in
arcseconds/pixel.
CCDSoft will take a short exposure
(~10 seconds) pass
the image to TheSky to be analyzed, then the exact center of the image is determined
by performing astrometry,
and the point mapped in
TPoint. Very slick!
TheSky6's - Tools
| Map Points
Create the az/alt target list
The process of creating an
evenly-distributed list of azimuth-altitude points for your location may require
several iterations of trial-and-error exporting and Auto-Mapping depending on
how complicated your local view of the sky is.
However, once a set of points works well you will not need to recreate them again. Just use the mapping points you have created for your location whenever you need
to re-map the telescope for any reason. This settings below happen to work
from my backyard. The big "gap" to the north is my house and my neighbor's
house. The starting and ending alt/az coordinates were read of the status
bar in TheSky where I noted the alt/az position when the telescope was pointed
at the obstructions.
User defined set
of points
Define the mapping points that work for
your location
(screen shot from version 5 applies!)
In order to limit the azimuth
starting point, click and drag the triangular pointer on the outside of the
circle and to a new starting position. To limit altitude, drag the small
white circle on the outside of mapping area. The inner white circle allows you
to limit the upper azimuth.
Limiting Altitude
(screen shot from version 5 applies!)
Once the azimuth and altitude
setting are defined, you can specify the density of points using the slide bar. Moving the slide bar to the right decreases the density. See diagram
below.
Slide Bar changes
density
Right decreases and left increases
point density
(screen shot from version 5 applies!)
For the first Auto-Mapping attempt,
select only a few stars (about a half a dozen) in close proximity on one side of
the meridian. Walk before you run. After successfully mapping just a handful of
points you can then export the data with more points and more sky coverage. If
your mount is a German Equatorial (GEM) like the
Paramount ME its a good idea to work one side of the meridian first,
then flip to the other side.
When Auto-Mapping, the data points in the model are as accurate as the scale in
arcseconds per pixel. A scale of 0.5 to 2.0 arcseconds per pixel is common.
This is more then accurate enough to create a good working
TPoint model. Since
Image Link does the work only one image per mapping point is
taken and there is no need to reposition the telescope and image again which
takes a lot of time when mapping hundreds of points. There is no better
more efficient way to map the points.
Few points for your
first attempt
Start off small first
(screen shot from version 5 applies!)
When everything works flawlessly
with a few points you can expand the coverage and increase the number of points. 200 points makes for a very good model but more is even better if you are using
ProTrack
with a Paramount! 100 mapped points generally takes a little more than 1 hour to
accomplish.
Once you have created your
list of data points (targets) use the Data | Data Wizard to Export the
data. In the Data Wizard use Query | Edit Parameters. You
will see the dialog below. First you must change from the default
format "Degrees or hours, minutes, seconds" to the "Decimal Degrees"
format or the data will not work with the automap Visual Basic Script (VBS)
without modifying it accordingly. Of course that is an option too if you
are up to the task of parsing the data string.
Database Query
Use Decimal Degrees format
Next use the tab "Object
Types and Databases" tab as shown below. The type of objects is
"Map Points" under the heading "Other Data Points".
Export the Map points
Under -Select databases/catalogs | Other Data Points
Because the data was
created by the "Map Points" Tool there is no need to apply any
additional filtering of the data. Although that is an option in this
case it is not necessary.
Select fields Azimuth
and Altitude
Under Report Columns as shown above
Press OK. The query is now ready to be "RUN". See below.
Here is the query
Note Total number of Objects (mapping points)
Each map point has been
numbered and the Azimuth and Altitude coordinates created. The text file
can now be EXPORTED to a mapping file or to the Clipboard. By
clicking the name of a field the data is then re-sorted by that field.
Download the above zipped
file and EXTRACT the file "map-points.dbq" into the default folder
\My Documents\Software
Bisque\TheSky6\Database Queries
then load it from there.
Scripting commands
added here
Add Take Image and Automap
By Exporting the script to the
clipboard it is then ready to be Pasted directly into Orchestrate for execution.
Export the Mapping
text file
Save the file for the auto-map script
Or to the Clipboard for pasting into Orchestrate
"\My Documents\Software Bisque\TheSky6\Database Queries" folder. Then you can simply load it (file open) in the Data Wizard and run the
query which is predefined.
NOTE: REMOVE the
Column delimiter as shown above in RED!
The default is placing a comma "'," between fields. When that is
done the text will not line up in straight even columns.
BEFORE removing the
column delimiter staggering fields,
Object name ,Azimuth ,Altitude
Map point # 1, 150.0000, 20.0000
Map point # 7, 3.0000, 48.0000
Map point # 8, 45.0000, 48.0000
Map point # 9, 90.0000, 48.0000
Map point # 10, 135.0000, 48.0000 <----- Columns not even when a delimiter is used
Map point # 11, 120.0000, 76.0000 <----- Columns not even when a delimiter is used
AFTER removing the column delimiter nice even columns!
Object name Azimuth Altitude
Map point # 1 150.0000 20.0000
Map point # 7 3.0000 48.0000
Map point # 8 45.0000 48.0000
Map point # 9 90.0000 48.0000
Map point # 10 135.0000 48.0000
Now nice even columns - easier to work with!
The name and path of the
text file you created above is then placed in the AutoMap VBS script as shown here.
'Use TheSky6 to generate a text file of mapping points
szPathToMapFile = "D:\mappingpoints\mapping.txt"
Note: There is one issue with the exported data
from TheSky6's Data Wizard!
There is a header line created in the mapping text file
as follows.
Object name ,Azimuth
,Altitude <------------ HEADER Not used!
The header created by the Data
Exporting of mapping data needs to be removed from the
text file (or ignored) because it is not valid mapping data. You could also edit the VB script and
check the incoming data then IGNORE any fields that do not contain
numeric valid mapping data. See below!
No problemo!
The Auto-Map script reads the text
using the sub routine "GetCoordinatesFromLine" as follows.
Sub GetCoordinatesFromLine(LineFromFile, dAz, dAlt)
if (Left (LineFromFile,9) = "Map point") then
dAz = Mid(LineFromFile,19,9)
dAlt = Mid(LineFromFile,34,9)
else
MsgBox("Ignoring this -> " + LineFromFile)
end if
' MsgBox("Azimuth is " + dAz + " Altitude is " + dAlt)
End Sub
Note the above will automatically
IGNORE any text in the file that is not valid mapping data. Place
a comment ' character in front of the line MsgBox("Ignoring this
-> " + LineFromFile) if you don't want to
be prompted when invalid data is encountered.
Note that the starting column for the
azimuth is 19 and the length is 9 characters. Altitude starts in
column 34 and is 9 characters in length. This is why you should
align the text first.
Remove the comment ' character in front of the line
below
' MsgBox("Azimuth is " + dAz + "
Altitude is " + dAlt)
if you wish to see the coordinates that will be slewed to. Great
for debugging but will require you to OK each mapping position if left
enabled. I do recommend starting with the debugging MsgBox first
so you can see if the data is being properly formatted. Then
comment the line out when you are sure it works!
If you take the time to draw your
actual horizon using the telescope this will become very useful for the Auto-Map
Visual Basic script. This is HIGHLY recommended for any permanently
mounted telescope and is very easy to accomplish. It does take sometime to
accomplish but you only need to do it once. When you have a good telescope
drawn or manually drawn realistic horizon make a backup copy of the file on
floppy for safe keeping. I am speaking from experience.
Use the Telescope | Telescope Line
Editor to trace your true horizon with the telescope. You do not need to
be very accurate and a finder or Telerad is really all you need. The less
the magnification the faster you can draw using the hand paddle or TheSky's
Telescope | Motion Controls.
Display of "True"
horizon
Draw your own horizon
Note the difference between the
"true horizon" versus the default theoretical horizon. If you have
correctly defined where the telescope can and cannot go the Auto-Map procedure
will be that much more efficient because you will not waste time slewing and
taking images where there are no stars. When
Error checking is off bad or invalid images will be ignored, i.e. behind a
cloud or a tree. However, why take an image of nothing and have
Image Link fail and then move on if you don't have to.
In the case of a custom horizon you can create as many mapping points as you
like and you don't have to be concerned with where they are placed in
TheSky. When the telescope encounters a point that is "out of bounds"
it simply searches until it finds a valid point to slew to. This goes on
until the script is complete. If you choose 100 points you may only have
70 or less that are actually mapped but it doesn't matter because all the points
that do map are perfectly valid points.
The horizon line can easily be created by following the telescopes position as
you trace your horizon with a wide field finder or Telrad! Use the
Telescope | "Telescope Line Editor" to accomplish this. See below,
Telescope | Telescope
Line Editor
Draw the Horizon with your telescope!
You may also use the motion
control dialog for position the telescope in Alt/Az or RA and DEC. This
can be done sitting inside while watching a monitor with a video camera/wide
field lens piggy backed on the scope!
Don't forget to "Save"
the Horizon
Make a backup on floppy, just in case
NOTE:
If you have your own "digital horizon" created for use with TheSky you can
actually use it! The button "Match Horizon Image"
above will do just that. Awesome! The example below uses the digital
horizon for the Software Bisque primary observatory located in Blue Mountain, Golden Colorado.
The images' azimuth position
indicated
How cool is that?
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