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HIFI Data Products. How it is stored, why it is stored that way, and what you need to know to use it. The system has a very object oriented approach to data storage. Consequences of this are: Data storage is hierarchical, and easy to follow conceptually.
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HIFI Data Products How it is stored, why it is stored that way, and what you need to know to use it.
The system has a very object oriented approach to data storage. Consequences of this are: • Data storage is hierarchical, and easy to follow conceptually. • In practical terms, getting a certain set of data is more daunting (initially). Contexts are top level containers. In HIFI, a Context stores everything related to a single AOT (observation) CONTEXT Products are more specialized containers storing different types of data. Quality, Science, etc. Products can store other Products, as will be shown. PRODUCTS PRODUCTS PRODUCTS PRODUCTS PRODUCTS PRODUCTS Datasets are, for the astronomer, the main item of interest. For HIFI, these would be the flux vs frequency data (i.e. the spectra) DATASETS DATASETS DATASETS
DATASETS The two primary dataset types are simply WBSSpectrumDataset HRSSpectrumDataset In the case of a WBS Dataset, data is normally split up into four spectral segments..1 for each subband.
HIFI Timeline Product The main ‘container’ product for HIFI data is known as the HIFI Timeline Product. It stores all the Spectrum Datasets related to a particular backend, in addition to a summary table describing what each dataset contains (science or calibration spectra). Each dataset itself is embedded in a ‘DatasetWrapper’ product.
HIFI Observation Context The main ‘container’ product for a HIFI observation is a CONTEXT. It stores the HTPs for each backend, as well as pointing, quality, and history information. (i.e. EVERYTHING).
Matching the data to files on your harddrive Everything is found in your local store directory. Users can store data either as Contexts, or as backend specific HTPs….it depends on the source of the data and how it is processed. The simple case of a single backend (HTP), the files are stored as follows: [~/.hcss/lstore/268435952_demo] >ls drwxr-xr-x 43 cborys staff 1462 Mar 5 15:48 herschel.hifi.pipeline.product.DatasetWrapper drwxr-xr-x 3 cborys staff 102 Mar 5 15:48 herschel.hifi.pipeline.product.HifiTimelineProduct [~/.hcss/lstore/268435952_demo] >ls herschel.hifi.pipeline.product.HifiTimelineProduct -rw-r--r-- 1 cborys staff 28800 Mar 5 15:48 hhifiwbsv268435952_htpv00.fits [~/.hcss/lstore/268435952_demo] >ls herschel.hifi.pipeline.product.DatasetWrapper -rw-r--r-- 1 cborys staff 273600 Mar 5 15:48 hhifiwbsv268435952_10_hspv00.fits -rw-r--r-- 1 cborys staff 273600 Mar 5 15:48 hhifiwbsv268435952_11_hspv00.fits -rw-r--r-- 1 cborys staff 273600 Mar 5 15:48 hhifiwbsv268435952_12_hspv00.fits -rw-r--r-- 1 cborys staff 273600 Mar 5 15:48 hhifiwbsv268435952_13_hspv00.fits -rw-r--r-- 1 cborys staff 273600 Mar 5 15:48 hhifiwbsv268435952_14_hspv00.fits