This section, combined with the previous one, covers how your data get reduced, or what we did to your data between when it left the spacecraft and when you get it. The Level 1 BCD products discussed in the previous section are for the most part what you should start with when working with MIPS data. In many cases, you can start with the 24 micron Level 2 post-BCD products. For Ge data in particular, the post-BCD data products are a good way to get an overview of your data, but to do science, you should revert to the Level 1 BCDs and make your own post-BCD products.
The Spitzer post-BCD tools can perform tasks including additional corrections for cosmic ray hits, illumination variations, cosmetics, and pointing refinement, as well as basic mosaicking of individual BCDs, source extraction, and bandmerging of point sources.
Technically, the suite of post-BCD software is more formally referred to as the ''Advanced Data Products Software,'' because the software is flexible enough to be used with more than just Spitzer data. However, in this context, we will simply refer to it as the ''post-BCD'' software. The post-BCD tools are available in a single package called ''MOPEX.''
In summary, the steps of the post-BCD processing are Background Matching, Pointing Refinement, Basic Mosaicking, Outlier Detection, Astronomical Point Source Extraction (APEX), and finally, Bandmerging of Point Sources. We refer you to the manuals available in the Data Analysis portion of the website for the nitty-gritty of how to run the software; the rest of this chapter addresses MIPS-specific issues and concerns. Suggested namelists for certain situations are given on the website and in the data analysis cookbook. See Figure 5.7 for a simplified flowchart of the post-BCD pipeline.
Figure 5.7: The MIPS post-BCD pipeline. Code and extensive documentation are available in the Data Analysis section of the website.