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MAST Interfaces
- The Web Interface
- HST "Pointings" Search
- MAST Web Services
- StarView
- The WWW interface vs. Starview
- Return to the Tutorial Index
There is a web based interface for most MAST missions.
The GALEX interface is similar, but relies on different underlying software and may differ from other
missions in some respects.
The heading for each form item is a link to a help page with more information on that field
and how to best use it in a search.
The mission search pages are listed on the Searches page
under mission specific searches. There is also a link to each mission search on the
"mission navigation bar" and under the Search & Retrieval left menu pullout
for the appropriate missions.
For the "file upload form", the top section helps you describe the format of a file
containing a list of targets or coordinates you wish to search on. Click on the column labels for additional help.
The local file name is the name of the file on your system.
The file must be an ASCII text file or table with one entry per line with the fields (e.g. RA and Dec) separated with
one of the allowed delimiters. Coordinates may be in several formats including sexigesimal or decimal degrees.
Use the form to designate in which column the target name or RA and Dec are to be found.
If appropriate designate the delimeter (tab, |, comma (,), semi-colon(;).
Choose the desired resolver or the "Don't Resolve" option.
HTML output
Above the output display is a link to allow numeric columns to be displayed graphically using VOPlot.
If a resolver (SIMBAD or NED was used), the resolver output is displayed. If you have chosen to display the
SQL used to search the database the query will be displayed.
A series of additional comments explaining various links may be included in this section.
A variety of links are available as part of the search output
(assuming the appropriate columns have been chosen for display).
The dataset name is usually a link to a preview page which includes a preview version of the image or
spectra as well as additional information and links. If the "reference" column is displayed
the number indicates the number of refereed journal articles in which the data has been used.
For HST, the references are categorized by proposal number, so not all individual observation
in that program may have been used.
For HST, FUSE, IUE and EUVE, the proposal id is a link to a listing about that proposal.
It includes the abstract, any associated journal articles and a listing of all the observations
acquired for that program.
Some observations have been used to create "High-Level Science Products" which are hosted at MAST.
The number in the column labeled High-Level Science Products indicates the number of products
associated with that observation. Clicking on that number to see a list of the products.
Also listed may be associated previews and readme files.
For spectral observations, you may choose to view the preview data by choosing the observations
to be plotted and then clicking on the "Plot marked spectra" button. The data will be co-plotted.
You may choose a variety of scaling factors to customize the plot and replot the data.
The customized plotting program may also be accessed from the preview.
To request data, mark the datasets of interest and click on the button to retrieve or download data.
For HST and FUSE data, a retrieval options form will give you a options for data delivery and
for the type of files to be requested. For IUE, you may choose to have final data product
(MXLO and MXHI) files downloaded or the "more options" file which will allow you to choose
among the NEWSIPS and the original IUE data products. Data for HST and FUSE will delivered
as individual files according to the chosen data delivery options. Other MAST data will be delivered
as a tar or zip file (as you choose) directly to your computer.
More detailed information about retrieving data from MAST is in
tutorial section "Retrieving Data".
Comma Separated Values (CSV) Output
The CSV output is a simple ASCII file containing column headings followed by comma-separated entries.
In file upload mode, a blank line is inserted between database queries.
(Note this option will execute more quickly then the others since it involves the
least amount of processing).
Excel output
VOTable output
The MAST "Pointings" interface allows a user to search for ACS, WFPC2, NICMOS,
STIS and FOC exposures in a powerful way.
The interface can be found at
http://archive.stsci.edu/pointings/search.php".
A description of how a "Pointing" is defined can be found on the
pointings search help page.
You can run the pointings search interface as a web service.
For each of these instruments we have assembled a searchable data table
that allows users to look for sky regions (or pointings)
which have been observed more than N times, observed with 2 or more filters,
or have been observed more than twice with a time separation of more than (or less than) N days.
Included in each table are the total number of exposures
for a pointing and the number of unique bands.
The table also lists the date/time of first and last exposure for every
pointing.
An example of the kind of query this table will allow is:
How many high galactic latitude observations exist [for RA between
9 - 18 hours in the northern hemisphere (dec > -20)
observable from the northern hemisphere
in the early spring] where there has been at least two observations,
and where at least one of those observerations was in the I-band, and
at least one of those observations was in any other filter?
Galactic Latitude Above & below plane +/- > 20.0 degrees
MAST data holdings may be searched not only using HTML search forms but also using HTTP GET requests.
The GET request allows the search parameters to be included in the URL.
As such, they can be called from within programs to automate data searches.
The results can be returned in a variety of formats including VOTable XML format, excel spreadsheet,
and comma-separated values which can simplify ingesting results into user-written programs.
In addition, submitting GET requests can bypass restrictions currently placed on the web search forms
(e.g., restrictions on the max_records value).
Additional information on and examples of how to utilize
the MAST web services is available.
StarView is an astronomical database browser and research analysis tool.
Developed in Java, StarView provides an easy to use, highly capable user interface
that runs on any Java enabled platform as a standalone application.
You can search for and retrieve HST, FUSE, IUE and EUVE data via StarView.
StarView contains extensive internal documentation, so currently we provide little
additional information about the StarView interface in this tutorial.
For more
information about StarView please visit the
StarView website.
The MAST Web Search and StarView have many capabilities in common.
Both provide a mechanism for searching the HST, FUSE, IUE, and EUVE
science databases. The MAST Web Search also provides access to
the other missions, catalogs, and surveys archived at MAST.
While the Web interface provides access to the science metadata which
fills the needs for most archive users, StarView permits access
to most of the tables in the HST database, providing
a view into engineering and instrument specific database tables.
A version of StarView has been integrated with the
Java based Astronomer's Proposal Tool (APT).
VTT can use StarView output to show the exact
pointing on the sky for HST archival observations, which can be a powerful
tool for planning HST observations.
Both interfaces provide access to HST image and spectral previews and searches of
HST proposal abstracts. The web interface provides access to previews for most MAST missions.
There are also proposal abstract searches for FUSE, IUE and EUVE on the web.
The web interface provides access to lists of papers that have utilized
the data in the search results for most missions. The web interface also provides
easy access to High-Level Science Products (HLSP) from the search results pages.
StarView incorporates the
Java based tool
SpecView thus giving access to an extremely useful plotting and analysis tool.
The Web interface gives access to a customized plotting tool that is accessible from the
search results page, from the preview pages, the MAST Scrapbook and a coplotting interface form.
Users may co-plot data from several instruments and adjust the scales to their preference.
To see how to use the spectrum combination/filtering functions see the
tutorial (in Powerpoint format).
Mission Web Search Interfaces
Search Forms
For most missions, there is a "standard form" and a "file upload" form which allows users to upload a list of targets.
The search forms consist of three sections.
On the "standard form", the top section consists of a place to enter a target name or coordinates.
When you enter the target name you can choose to have the coordinates looked up via SIMBAD or
NED using the Resolver options field. The search is then done using the coordinates returned from
the selected resolver. You may choose to search on a character string by choosing the
"Don't Resolve" option in the Resolver options field. To maximize the chance of finding the targets,
surround the choice with wild cards e.g. *Jup* to find observations of Jupiter.
You may also choose the search radius (the default is to 3 arcmin).
The middle section of the search page contains mission specific fields, that can be used to perform the search
such as dataset name, exposure time, start time, dataset name and observers name.
Users may choose up to two additional fields by clicking theto "User-specified fields"
at the bottom of the middle section of the web-based form. For more information about each field
click on the link "Field Descriptions". This brings up a page of all the available columns
the database column name, the label, the data type, the valid values in that
field, and additional notes where applicable. All columns are included in this table so it can be
useful resource when using the fields included on the form.
The third section gives you choices for how to format the output of the search results.
On the left side a list of columns that is displayed. These default columns
were chosen as the most commonly needed columns.
You may remove any of the columns by highlighting that column and clicking on the remove button to the right.
You may add columns by choosing columns from the select box below and clicking the add button to the left of the
select box. You may choose the order by clicking on field in the output columns box and click on the up and down
buttons to the right. Clicking on the reset button will restore the default output columns settings.
You may choose to sort the output by up to three columns.
You may choose four output formats: HTML, comma separated value text, Excel spread sheet,
and VO table format. The HTML format is the format that will give access to previews and other useful links
as well as retrieval options. Click on the headings for additional help.
Search Results Output
The main item of interest on the output page is the listing of rows found as a result of the search.
As a default only the first 100 rows are displayed. One of the output options is to increase the
number of rows displayed. Be aware that when a large number of rows are displayed, the page may
render very slowly. The Mark button column for proprietary HST and FUSE data is displayed
with a yellow background to easily flag those data as proprietary.
The search results are stored as an Excel spreadsheet table (note: assumes users computer/browser provides support for Excel-format files).
Search results are returned in an XML file format developed by the NVO project. For searches returning results
from more than one mission and/or target, multiple "resource" tags are created.
Searches with a radius of 0 will return a VOTable file listing the output fields
for that particular mission/catalog. (See VOTable documentation.)
HST Pointings Interface
Band I >0
Number of Unique Bands >1
Total Number of Exposures >1
RA 09..18
Dec >-20.0
MAST Web Services
StarView
The Web Interface vs Starview
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