TESS

Revision as of 00:46, 26 July 2019

TESS

This page summarizes some aspects of the processing of TESS full-frame images using the tools provided by the FITSH package.

How to start, what do you need

• A local copy of the calibrated full-frame TESS FFIs. These files can directly be retrieved from MAST, using the link of http://archive.stsci.edu/tess/bulk_downloads/bulk_downloads_ffi-tp-lc-dv.html. Here, go for the section Full Frame Images and, within then, take look at Calibrated FFIs. There are the download scripts named tesscurl_sector_1_ffic.sh, tesscurl_sector_2_ffic.sh, ... one for each sector.
  • The simplest solution is to use these scripts directly to retrieve the files. Since these scripts retrieve just a bunch of files (without any particular directory tree), you may create some filesystem-level standard for the storage. A recommended directory tree can be /pub/tess/ffi/cal/s1, /pub/tess/ffi/cal/s2, ... for TESS Sectors 1, 2, ... respectively.
  • In each of these directories, there will be ~15500 ... ~20600 files. Each of these files has a size of 34 megabytes - therefore, in total, 520 ... 700 gigabytes for are needed for each directory. Up to Sector 12, the total volume is 7.6 terabytes.
  • These file-by-file retrieval tesscurl_sector_*_ffic.sh scripts are not so optimal in many sense. There might be a need of a day (20 ... 28 hours) to retrieve a single sector. However, you can speed up this process by using these instructions.

• A local copy of the DR2 data release of the GAIA catalogue. The full catalogue is available via the GAIA archive, most importantly from this directory: http://cdn.gea.esac.esa.int/Gaia/gdr2/.
  • One can create a similar filesystem hierarchy like for the calibrated TESS FFI archives, e.g. it can be put into the directory /pub/gaia/gdr2
  • The total size of the GAIA DR2 (GDR2) catalogue is around 567 gigabytes: this amount of data has exactly the same order of magnitude like a single TESS sector, so it indeed worth to download it.
  • The 98.8% of the GAIA DR2 data volume is in the point source catalog in the format of gzipped CSV files. Following the aforementioned standard, these files are then located in the directory /pub/gaia/gdr2/gaia_source/csv. Here, there are 61234 *.csv.gz files, named and organized according to their HEALPix coverage