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SIP 2.20 Beta
[To open a SIP window click on the "Start SIP" button above (once
everything is done loading). Example
images to load from this server are m51dss.fit, m1dss.fit, m13dss.fit,
m51ccd.fit, atlas1.fit, and atlas2.fit (use lower case letters). For
instance, after selecting the menu item "File, Open Image File from the
Internet..." enter
"http://www1.phys.vt.edu/~jhs/SIPbeta/images/m51dss.fit" in the dialog box.]
SIP is an astronomical image processing program
which runs over the Web. This package was written specifically for students (SIP
could stand for "Student Image Processor," or "Standard Image
Processor," or even "Simple Image Processor"). While SIP is designed for
use by instructors and students at any educational institution, it can
certainly be used by anyone with access to the Web. The program provides
simple, yet quite general tools that enable the user to carry out
standard CCD image processing procedures. Complicated procedures (e.g.,
unsharp masking) can be accomplished in a step-by-step fashion, using
the tools provided, allowing the user to learn and understand how the
procedures work (no "black box" procedures). The author is John Simonetti, a faculty member
of the Department of Physics at Virginia Tech.
The program is written in the Java(tm) programming language in
order to make it usable over the Web. It should run on any machine
with a Java 1.1 compatible web browser; for more details see Will SIP run on my machine?.
The goal of the SIP project is to provide a means for students to
learn how to accomplish the three major tasks of astronomical
imaging:
- image processing and analysis -- combining images,
or massaging images in order to extract quality information present
in those images. What is the structure of distant galaxies?
- photometry -- measuring the precise brightness of
variable stars or flickering quasars, for example. Studies of variable
stars yield measuring sticks for determining the size and age of the
universe.
- astrometry -- measuring accurate positions of
moving asteroids or comets, for example. Position measurements of
asteroids yield the data necessary to determine accurate orbits --- when
will we discover that a near-earth asteroid is on a collision course with
Earth?
These tasks, while of basic astronomical importance, are similar to much
of the image processing and analysis done in a wide variety of
scientific and technological fields. In this regard, astronomical image
processing and analysis provides these experiences
in a subject which has universal appeal to students. For information on
how to use SIP for these tasks, and for example materials, see the links
on the left side of this page.
Starting SIP
Click on the "Start SIP" button near the top of this page to open a SIP
window. Example images to try loading from this server and playing with
are m51dss.fit, m1dss.fit, m13dss.fit, m51ccd.fit, atlas1.fit, and
atlas2.fit (use lower case letters in the names as shown; image credits). For instance, after selecting
the menu item "File, Open Image File from the Internet..." enter
"http://www1.phys.vt.edu/~jhs/SIPbeta/images/m51dss.fit" in the dialog box.
In browsers that can run signed applets you can also load images from
your own machine or any location on the web (if you explicity give the
applet permission to do so). See the links at the left side of this page
for other images.
Mac users may not see a "Start SIP" button. Button or
no button, Mac users will want to read Will SIP
run on my machine?.
(For the Java-knowlegable, the SIP applet has been
signed; the digital "signature" is "Virginia Polytechnic Institute and
State University" (Virginia Tech). A signed applet cannot be tampered
with by anyone. For more information on signed objects, and digital IDs
see Netscape Object Signing: Establishing Trust for Downloaded
Software. Also, please see the disclaimer at the end of this
page.)
Why SIP?
Why use SIP as an image processor? SIP is unique in many ways. When
using a browser that can run signed applets, SIP can load images not
only from your machine but from anywhere on the Web. The program is
loaded into your machine along with this Web page. This means you never
need to worry about installing the software, or any upgrades. You always
get the latest version. Once you click on the Start SIP button the
program runs on your machine (not on this server), so you also get the
speed advantages available to a program run off the local disk.
An instructor in Astronomy can use SIP to enable students to load and
analyze images from anywhere on the Web (including the instructor's own
collection placed on a local Web server). The instructor can be assured
that everyone gets the same program, without the students or the
instructor having to load any software onto any machines. Students can
do the work from any computer: in a collective lab setting, from a
campus computer lab, or from home. This sort of decentralized,
distance-learning usage was the main motivation for writing this program (we
use it in our Introductory Astronomy course, and plan to use it in our
public and school outreach programs).
Finally, what's with the name? Well, you "sip" java, don't you?
Sign Up as a SIP User!
Please consider signing up as a SIP user. Web-distributed software, such
as SIP, provides some advantages to the user compared to, for example,
commercially purchased software: it's free, it requires no installation,
upgrades occur without the user having to bother with another
purchase/download, and anyone can use it anywhere they can sit down at a
computer with internet access. However, the developer (me) has one
problem: I can't easily tell how much interest there is in SIP! It helps
me, personally and professionally, if I can show that there is interest
in SIP. Please show your interest in SIP by signing up as a SIP user. In addition to helping
me by signing up, if you choose to, you can receive a periodic e-mail
newsletter about any improvements in SIP and other related information.
The sign-up page has more information about
signing up and about the newsletter.
SIP Poster at Atlanta meeting of the American Astronomical
Society
I presented a poster
on SIP at the AAS meeting in Atlanta
(January 11-15, 2000).
jsimonetti@vt.edu | VT
Physics | Virginia Tech | Java
This work was partially funded by grants from the
Center for
Excellence in Undergraduate Teaching at Virginia Tech.
Java and all Java-based trademarks and logos are
trademarks or registered trademarks of Sun
Microsystems, Inc. in the United States and other countries.
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Disclaimer: Neither I (John H. Simonetti), nor Virginia
Tech make any representations or warranties about the suitability of this
software (SIP), either express or implied, including but not limited to
the implied warranty of fitness for a particular purpose. Neither I nor
Virginia Tech shall be liable for any damages suffered as a result of using
this software.
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