Roman Ground Tests

Roman science Instruments were tested prior to launch for functionality and to characterize the detector response. The data from these tests have been stored in the Roman Integration and Test Archive (RITA) to support the generation of calibration reference files, and to provide a baseline for post-launch instrument performance. 

CaSSI Interface

The MAST CaSSI web interface includes a RITA search form for data obtained during  pre-launch ground testing, including epochs of Thermal Vacuum (TVac) testing. The RITA web interface is shown in Fig. 1.

Most elements of the interface (pull-down menus, checkboxes, buttons) are similar to those in other MAST web interfaces (see the Mission Search Guide). Features specific to RITA are summarized in subsections below, followed by some definitions of common acronyms. 

Provenance

After selecting the RITA Data Group (see Roman Mission Products), use the Provenance pull-down to select the specific ground test and instrument (e.g., WFI TVAC 2). 

General Attribute Selectors

Attributes of the test data (selected metadata stored in the RITA database) may be used to narrow your search to products of interest. Not specifying an attribute has the effect of matching all products with respect to that attribute (e.g., an unspecified Detector name will match all detectors). 

Dates

If the date when the data were generated is known approximately, the start/end date selectors will limit the scope of the search. For reference, the dates of the ground tests are given below.

Name of the Ground Test

Exposures were obtained to support the various test activities. For a summary see TVAC Flash Cards.

Optical Elements and Calibration Source

One or more of the WFI Optical Elements may be selected from the pull-down menu (see the Spectral Element widget description). You may also select whether the Relative Calibration System (RCS) was on during the exposure, and whether an apparent point-source was generated with the SORC. 

Optional Attribute Selectors

Most all metadata (each of which corresponds to an output table column) can be used to further constrain the search. Select the column name from the pull-down menu and apply a condition (i.e., a constraint), as show in the article on Additional Search Parameters. The example below shows how to select only data where the exposure type matches the string WFI_IMAGE. 

Display Fields

Use the pull-down menu to select which metadata (fields) to display in the results table. There are buttons to select all fields () or none (). Fig. 2 highlights the Exposure Type field, which may be selected. 

Results

A successful search will be displayed as a table, shown in Fig. 3, with one row per matching product. The Search Results Page article describes general features of the search results table, including selecting files for download. Fig. 3 below shows a somewhat simplified pull-down menu for download, since the results table for RITA is simply a list of files, rather than a list of collections of files. 

See the schema for the TVac asdf-format files for information about the metadata contained in the exposure data products. 

RITA Common Terms

The following terms are important for creating meaningful queries for TVac data. Some of the instrument components are visible in the Description of WFI. See the Roman acronym list for more definitions.

API for RITA

A simplified python interface for RITA is planned. For now, you may download from CaSSI and use curl scripts to query for products, and to retrieve them. The query scripts can be adapted from those that are available in the CaSSI web interface. The tables below shows the button/menu options that generate the queries, and the corresponding curl commands. (Backslash characters have been inserted into the example commands in the tables below to make them more readable.) Simply run the queries on the command line to generatae

Query

You may delete the limit of 5000 results (bolded text) from the search command, but be aware that larger queries may take a long time to produce results. The result will be a json-formatted file of results: one for each row of the results table that would be generated after a search of RITA. 

Retrieve

You may also retrieve data using curl, as illustrated below. Note that your MAST authorization token is read from the shell environment variable MAST_API_TOKEN (see bolded text). The token is necessary to assure that you are authorized to retrieve products from RITA. To generate a token, see the Auth.MAST page.

For Further Reading...

• RITA search
• CaSSI.MAST API
• WFI TVAC file formats
• Description of WFI
• TVAC Working Group (Innerspace)