Contributed Software: Tiny Tim for Spitzer
SPITZER HOME - SPITZER SCIENCE - INSTRUMENTS - SCIENCE USER SUPPORT - SEARCH
News
Research Categories
Science Schedules
Advisory Groups
Observing Rules
Data Analysis Funding
Exploration Science Program
Legacy Program
First-Look Survey
Observatory & Instruments
Overview
PCS
IRAC
IRS
MIPS
AOTs
Science User Support
Proposal Kit
Documents
Tools
Approved Programs
Observing Schedules
Data Archives & Analysis
Science Archive Access
Post-BCD Tools
Tiny Tim for Spitzer
Version 2.0
June 2006
Developed by John Krist
for the Spitzer Science Center
Get help from : help@spitzer.caltech.edu
Tiny Tim is a program for computing point spread function (PSF) models. It was originally designed for simulating Hubble Space Telescope (HST) PSFs and has been in wide use by the HST community since it was introduced in 1991. At the request of (and under contract to) the Spitzer Science Center, a new version was developed in early 2000 specifically for Spitzer. Only Tiny Tim/Spitzer is described here; the HST version, which is a completely separate program, can be obtained from http://www.stsci.edu/software.
Tiny Tim/Spitzer is written in standard C and is distributed as source code. It has been successfully compiled on a variety of systems, including UNIX, Microsoft Windows, and Linux. It s not fancy - there are no widget interfaces or fancy graphics. It simply asks a few basic questions and then goes off and computes the PSF model.
Tiny Tim/Spitzer is not an optical ray-tracing program, like Code V or Zemax. Those programs are used to design optical systems and determine their performance. Tiny Tim is hard-coded to easily model PSFs for specific optical systems, using parameters (aberrations, vignetting properties, etc.) derived from ray tracing software and measurements of on-orbit data. Information from other sources, like spectral sensitivities and detector characteristics, may also be included.
Questions and comments should be
directed to help@spitzer.caltech.edu.
Uses
of Model PSFs
Model PSFs have been used for a wide variety of applications:
- Proposal planning: predict limiting sensitivities and resolution
- Photometry: PSF profile fitting by the shifting and scaling of
models; testing completeness by generating synthetic images
- Algorithm testing: photometric, deconvolution, and dithering
algorithm testing
- PSF subtraction
- Data modeling: convolution of model data with model PSFs to
simulate observed images
Installation, Compilation, and Documentation
The Tiny Tim/Spitzer manual is available here. The source code for Tiny Tim is provided in a gzip-compressed tar file. This file should be downloaded in binary mode and then unpacked on your machine, like so:
The tarball will be unpacked in a directory called stinytim. Information on how to compile the code is available in the documentation.
The Tiny Tim/Spitzer manual is available here. The source code for Tiny Tim is provided in a gzip-compressed tar file. This file should be downloaded in binary mode and then unpacked on your machine, like so:
gunzip stinytimv2.0.tar.gz
tar xvf stinytimv2.0.tar
tar xvf stinytimv2.0.tar
The tarball will be unpacked in a directory called stinytim. Information on how to compile the code is available in the documentation.
Observers using Mac should try this version, and compile using "make other". The compiler will produce multiple warnings about M_PI, but these are not important.
Instrument Notes
Extensive instrument notes are available in the documentation. Additional notes are provided here.
- IRS: For the spectroscopic modules, the calculated PSF is that seen by the slit. The models do not include any optics beyond the focal plane
Acknowledging Tiny Tim/Spitzer
If you use Tiny Tim/Spitzer in a publication, please include the following acknowledgment:
"This research made use of Tiny Tim/Spitzer, developed by John Krist for the Spitzer Science Center. The Center is managed by the California Institute of Technology under a contract with NASA"
