SPS is a stand alone package for obtaining photometry from digital format astronomical images. It was developed by Ken Janes (Boston University) and Jim Heasley (Univeristy of Hawaii). In developing SPS we have adopted what we believe are the best features of many well-known photometry packages including DAOPHOT (developed by Peter Stetson) and DoPHOT (developed by Schecter and Mateo). The basic operating principles of SPS, along with a comparison of photometry from our original version of SPS to that obtained with IRAF/DAOPHOT and DoPHOT, are described in 1993, Pub. Astron. Soc. Pacific, 105, 527. The abstract of this paper is available on-line. Click here to see some sample photometry obtained with the SPS software. The newest release of SPS, version 2.0, incorporates a number of improvements over the original relase of the code.
User friendly operation through menu driven interfaces. An automated operation mode is also available, and batch operation is possible by sending menu commands to the program through standard unix file redirection. On-line help is available for all menu items.
Integrated routines for manual and automatic star finding, psf generation, aperature and psf photometry, and artifical star experiments.
Standalone operation on FITS format images.
Image display interfacing to the SAOIMAGE, XIMTOOL, and other display programs that use the IIS imtool protocol to display data. This feature allows for star finding and interactive photometry as well as viewing star-subtracted images after psf fitting.
SPS was developed and tested on Digital Equipment Corp Decstation 3100 and Sun Sparcstations using the Fortran compilers provided by these vendors. For these machines, we have tested SPS extensively under DEC Ultrix, OSF/1, and Sun 4.1.X and Solaris OS operating systems. The software has run on workstations with a little as 8 MBytes of memory but we recommend at least 16 MBytes of memory for regualr operation, including parallel operation of SAOIMAGE or XIMTOOL for image display.
SPS is written in Fortran 77 and includes several C language routines for special functions. Porting the code to other platforms should be straightforward. A standard test image and output are available to allow users to determine whether their SPS installation (or port) is operating as it does on the author's workstations.
Release 2.0 of SPS is now available for distribution. This new release incorporates several new features as well as some minor bug fixes that have been discovered.
SPS now supports spatially variable PSFs using the same quadratic model used in DAOPHOT II.
The program dimensions for images and stars lists can now be specified at compile time. Two standard configurations are supplied with the program for 1024x1024 and 2048x2048 images. Other configurations can be generated by the user to meet specific requirements.
The image display interface has been completely rewritten using the IRAF Client Display Library (CDL) routines developed at NOAO. SPS should now be able to communicate with any image display tool using the IIS imtool protocol. SPS can now load original and residual images directly into the display tool without first copying them to disk. For display servers that support multiple frames, SPS can now load the original and star subtracted frames into different frames and blink them. (This does not work with SAOIMAGE which only provides a single frame.) The program can ``launch'' either SAOIMAGE or XIMTOOL applications direclty. Private communication pipes are now supported between SPS and the image display tool.
A new ``RESKY'' tool has been added that allows the local sky to be determined by using the histogram of pixels in the star subtracted residual image after stars have been measured, fit, and removed. This will allow for more accurate sky determinations in crowded fields.
FITS image format is now the default image type used by the program.
The SPS software can be obtained via anonymous ftp on hubble.ifa.hawaii.edu (128.171.2.5). The software is distributed as compressed tar files ( the newest release is in sps.2.0tar.Z) Because we have limited time to support SPS (other than for our own use), we ask that anyone who wants to use SPS register with us in order to obtain software updates and bug reports. To register simply send us email asking to become a registered user---it costs nothing to register! Our distribution policy is that we will only provide support to registered users. A mailing list of all registered SPS users will be maintained by the authors.
You can reach us by email to janes@hyades.bu.edu or heasley@hoku.ifa.hawaii.edu.