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The Advanced Search Window

Advanced searches, using an expanded set of metadata, are provided for certain MAST data collections, including the default search of MAST Missions. Clicking the Advanced Search link below the Portal target name/coordinates dialog box will bring up the MAST Advanced Search window, which is shown below.

The Advanced Search Window consists of metadata filters which may be used to constrain the search results. The number of matches to observations with the applied filters is displayed (1: top), the Applied Filters panel displays the names and values (2: second from top), the available filter Columns panel (3: lower left), and the selected dialogs in the Filters Panel (4: lower right).

Applied Filters Panel

Filters for which values or ranges have been applied are summarized in the Applied Filters Panel. Filters may be removed individually, or with the Clear All button. Specific filters may be selected in the Columns Panel; values or ranges of values may be set in the individual Filter dialogs.

The term "filters" is, unfortunately, overloaded. Astronomers often think of filters as passband-limiting optical elements. In this context, filters are used to select a subset of available results using one or more criteria.

Search Parameters

The Advanced Search enables custom searches with a wider variety of criteria that may, but do not necessarily, include a target name or coordinates (as with Basic Search). As criteria are applied, preliminary searches will be performed in the background to update the Records Found count at the top of the window. This helps narrow the search to a manageable number of results. 

The count of search results must be <50,000 to load the results into the MAST Portal, or <500,000 to download the results to a local file.

Search criteria are specified by:

  • selecting one or more available filters in the Columns panel, and
  • specifying the values (or range of values) in the corresponding dialogs in the Filters panel.

Columns Panel

Click entries in the Columns Panel to toggle whether a given filter appears (checked) or disappears (unchecked) in the Filters Panel. You may also restore the default filters or hide all of them by clicking the appropriate text at the top of the panel.

Type the name of a filter in the Filter Columns dialog to show (or limit) the filters that are displayed in the columns panel.

The column names shown in the panel (left) may be different, depending upon which collection is being searched.

Filters Panel

Filters dialogs come in three flavors depending upon the type of parameter, as described below.

Enumerated Filters

Click one or more checkboxes to apply filters with enumerated values. If there are a large number of possible values (e.g., for instrument names), simply click the Name text at the top-left of the filter panel to sort the values in alphabetical order. The desired value may also be typed into the dialog box at the top of the panel.

Typing part of a value (e.g., HR) will limit the number of enumerated values to those that contain that character sequence. Then just check the box to choose one.

Text Filters

Type in the text box and press "return" on your keyboard to apply a filter with a text value. Text values may contain a wildcard (asterisk) character.

Wildcard values may not be used in the Object Name or Position filter.

Filter Ranges

Use the sliders to constrain a range, or simply enter floating-point values into the text boxes. The value is applied after the mouse focus is changed.

Available Filters

About 30 filters are available for restricting search parameters. They map to user-accessible metadata in the MAST CAOM (Common Archive Observation Model) database.

Column NameField TypeDescription

Object Name or Position

TextSearch for a given target name or coordinates, which is analogous to the primary search Portal search bar (see Basic Search).
Observation TypeEnumRestrict the search to 'science' or 'calibration' observations.
MissionEnumName or acronym for the mission that obtained the data.  High-Level Science Products are collected in the 'HLSP' mission.
Provenance NameEnumIdentifier of the software or team that produced the data.
InstrumentEnumAcronym for the science instrument used to obtain the data.
ProjectEnumSimilar to the 'Mission' field (identical in most cases) but reflects the originating mission, e.g. HST-based HLSPs will have 'HST' in this field.
FiltersEnumSelect one or more specific instrument filter names (i.e., pass-bands).
WavebandEnumDesignation of wavebands (broadly defined).
Target NameTextTarget name or field as specified by the PI in the observing program.
Target ClassificationEnumTarget classification in the STScI proposal database, such as 'STAR' or 'GALAXY'.
Sequence NumberTextThe meaning is specific to a missions, e.g. the Sector number for TESS observations.
Observation IDTextSearch for a specific observation ID or similar observation ID's using wildcards.
RARangeSpecify a range of Right Ascension. Values are displayed in sexagesimal but can be entered in degrees.
DecRangeSpecify a range of Declination. Values are displayed in sexagesimal but can be entered in degrees.
Proposal IDTextFilter on proposal/program ID number. Remember to zero-pad on the left to 5 digits, or use a wildcard character.
Principal InvestigatorTextFilter on certain Principal Investigator names. Wildcards are advised.
Product TypeEnumSpecify certain data product types, such as 'image' or 'spectrum'.
Calibration LevelEnumFilter on numerical calibration levels assigned to observations. High-Level Science Product (HLSP) data are designated Level 4, while planned-but-not-executed observations are Level –1. The meaning of a level is mission-specific.
Start TimeRangeSpecify a range of observation start date-times in UTC
End TimeRangeSpecify a range of observation end date-times in UTC.
Exposure LengthRangeSpecify a range of exposure lengths in seconds.
Min. WavelengthRangeSpecify a range of lower-bound wavelengths in nm.
Max. WavelengthRangeSpecify a range of upper-bound wavelengths in nm.
Observation TitleTextFilter on specific proposal titles.
Release DateRangeSpecify a range of data release dates.  For Exclusive Access data, this date may be in the future.
Proposal TypeEnumFilter on specific proposal types, such as 'GO' or 'SNAP'.  The appropriate types will vary by mission.
Data RightsEnumFilter for 'PUBLIC' or 'EXCLUSIVE_ACCESS' data permissions (or 'PROPRIETARY' but this is being phased out going forward).
Moving TargetEnumUse this boolean flag to filter moving target objects.
Product Group IDTextFilter on product group ID's from MAST databases.
Object IDTextFilter on object ID's from MAST databases.

Executing a Search

After adding the desired search parameters, there are two options to inspect the matching observations.

Click the Search button to load the search results into a tab in the MAST Portal.  The 'Records Found' count must be under 50,000 for this option to become available.

Click the Export Table button to download the table of search results as a file (CSV, VO Table, or JSON). This will work with search result counts up to 500,000.

This dialog box is launched when the user selects 'Export Table' after formulating a search.

For Further Reading...

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