Figure 1. The masthead and tabbed
format of the user interface.
The URL for the SDA User Interface (UI) is http://archive.acs.pha.jhu.edu/ui/>. Only members of the ACS GTO science team and affiliates approved by the Principal Investigator may have access to the SDA. Access to the SDA is granted through a password-protected user account, the name and password of which can be obtained from the "acssci" restricted webpage located here.
Each science team member will ultimately be given his or her individual SDA account. Until these individual accounts are implemented, use the generic account described above. The UI tools and functions access two different servers, so you may be queried for your account password several times during a UI session. If you activate your browser's "remember password" option, you shouldn't be prompted more than three times. This repetitive feature will be remedied in the near future.
The UI is a tabbed interface. Its main page resembles tabbed folders in a drawer, wherein each folder contains the functions for defining input and output parameters for object catalog queries and displaying the query results. Immediately above the tabs are action buttons for resetting the UI ("Start Over"), browsing and retrieving images from the SDA ("Data Inventory"), and submitting an object query ("Submit Query"). Contained in the SDA masthead are links to the UI release notes and this guide to the UI. The UI's masthead and tabbed format are illustrated in Figure 1.
All activities performed with UI v1.8.1 -- queries of object catalogs, generation of object maps and cutout images, archive set summaries, object summaries, etc. -- are rendered as World Wide Web URLs. As with any web page, these URLs can be bookmarked and annotated. This feature allows the user to recall important or common activities without repeating the steps required to generate the desired results.
Access to all images, their pedigrees, CALACS and APSIS processing information, and associated program information is obtained via links on the Science Data Archive Inventory page.
The SDA Inventory page is generated dynamically when the "Data Inventory" button is clicked. As before, the page lists all the GTO programs for which data are available in the SDA. It also provides the run (or creation) dates of all CALACS and APSIS data, as well as the SDA set numbers associated with each ingested APSIS run. Note that CALACS images may be associated with several APSIS runs, so they are not assigned set numbers. A sample region of the SDA Inventory page is shown in Figure 2.
The first column in the Data Inventory lists the STScI program numbers assigned to each GTO science program. Each program number is linked to a dynamically generated Program Summary that lists all CALACS images associated with that program and stored in the SDA. The images are identified by target, filter, and detector (Figure 3). Note that all parallel images are listed last under the target name "ANY." To view only the latest versions of the archived files, click "Show latest files". (NOTE: This function has not yet been fully implemented. Only the latest versions of files are currently shown.) To view the relationships between a CALACS image and any APSIS image products, click the "pedigree" function in the rightmost column. To download or view a FITS image, click on the "download" function in the same column. Clicking "Program Information" will connect you to the PRESTO program information page at STScI.
The fourth column in the Data Inventory lists the set numbers assigned to each APSIS run stored in the SDA. The products of these APSIS runs are images and object catalogs. Clicking on the set number will produce a Set Summary page, which lists all input CALACS images (arranged by target and filter), output APSIS images (arranged by APSIS module), and APSIS run information associated with that archive set (Figure 4).
To download or view a FITS image, simply click on the file name. To view the modules and switches used by APSIS to process the data, scroll to the bottom of the page and locate "Pipeline information." Clicking on the module names will produce detailed descriptions of the software packages and parameters used by the modules associated with that APSIS run.
To view the relationships between the CALACS and APSIS images associated with an archive set, click the "Image Pedigree" link located below the title banner of the Set Summary page. This action generates a page containing basic information about the detection image generated by APSIS and a pedigree chart showing the antecedent and descendent images associated with the detection image (Figure 5).
The user can navigate through the pedigree chart by clicking on any image box in the chart. A new page will be built around the selected image, which is now featured in the information block and highlighted in the pedigree chart. The "Show all relationships" link produces a pedigree chart in which all the images associated with the archive set are displayed. The "Text only version" link produces the non-graphical pedigree chart featured in UI v1.0.
The Set Summary page has two features that allow the user to quickly inspect (1) the drizzled and combined APSIS images and (2) a list of objects in those images detected by APSIS. These features are accessed through the "Object Map" and "Object Search" links located below the title banner of the Set Summary page.
Clicking "Object Map" produces a three-color JPEG image constructed on-the-fly from the drizzled filter images associated with the set. (For sets containing more than three filters, only the reddest three filter images are used.) Initially, a full but diminished (binned) map of the entire image is displayed. A control panel located at the upper right of the browser window allows the user to inspect regions of the image with adjustable field-of-view and magnification. The region is defined by a red box that appears on the small finder image in the control panel. The center of the box is set either by clicking on the desired location in the finder image or by typing the x and y coordinates in the designated text boxes. The box can also be dragged around the finder image by depressing and holding the appropriate mouse button. The size of the box (i.e., the field of view) can be adjusted by typing in the desired values of width and height. The magnification (or binning) of the displayed image can be selected via the drop-down "zoom" function. Once the position and zoom are selected, click "submit" to view the region. The image can be downloaded by clicking the "JPEG" or "PNG" links below the image. Figure 6 illustrates the region-viewing functions of the Object Map.
The Object Map features links to all objects detected by APSIS. The APSIS catalog number of a detected object can be determined by hovering the browser pointer over that object. Clicking on the object spawns a pop-up Object Summary for that object.
To view the Kron apertures of all the objects detected by APSIS, click the "Kron apertures" box in the control panel and then click the "submit" button. The map will be regenerated as a color image with overlaying apertures. To remove the Kron apertures, again click the "Kron apertures" box and then click the "submit" button. Images with aperture overlays can be downloaded by clicking the "JPEG," "PNG," or "PDF" links below the image. To preserve printer toner, we recommend inverting the color palette by clicking the "Invert color" button in the control panel (Figure 7).
To generate a list of all objects detected by APSIS from the detection image, click the "Object Search" link located below the title banner of the Set Summary page. (If you are currently viewing the Object Map, click the "Set Summary" link to return to the Set Summary page.) The UI will then perform a standard query of the detection catalog for that archive set and will display the default output in the Results tab of the UI's tabbed query form. The user may alter or refine the query and examine the results by means described in the next section (Querying Object Catalogs) of this guide.
As you enter the UI, the "Input Parameters" tab is automatically viewed (Figure 8). Begin your query by selecting a category from which you wish to define some constraints. The categories include the Detection, Filter, Photometry (Multicolor), and BPZ catalogs from APSIS and the CALACS image header keywords. (The last category is not available in v1.8.1, but will be available in v2.0.) Selecting a category will load into the leftmost drop-down windows the parameters associated with that category. If you are unsure of the meaning of the parameters, click the "category help" button in the lower right corner of the category box. The middle drop-down windows contain the logical operators for constraining the selected parameter. The numeric or string limits for the selected parameters are entered in the rightmost windows. If you wish to make more than three parameter constraints within a category, click "add line" and another line of windows will appear. Reset buttons within the category boxes allow easy erasure of single parameter contraints or the whole category.
If you wish to contrain your search using parameters from a second category, then move to the next purple category box and repeat the actions described above. More categories can be added by clicking "Add category." When you have completed defining the constrains of your query, click the "Continue >" button at the bottom of the page or the "Output Parameters" tab at the top of the page.
The Output Parameters tab lists the categories of fields that may appear in the query results. The categories are the same as those in the Input Parameters tab, except for the added "Aligned" category, which contains information about image alignment by APSIS. (The "Calibrated" and "Aligned" categories are not available in v1.8.1, but will be available in the v2.0.) Selecting a category produces a list of available parameters with selectable check boxes (Figure 9). You may select as many outputs as you wish, or use a set of predefined default parameters by clicking "Use Defaults." To select output parameters from other categories, simply select another category and check the parameter boxes. All previous selections from other categories are saved.
Each category contains some parameters that are always displayed in the output. These fixed output parameters are denoted with a permanent check mark.
Once all desired output parameters are selected, click the "Submit Query" button in the upper right corner of the UI. This action will automatically move you to the "Results" tab. Large queries may take several seconds to complete, so be patient. (To prevent runaway queries, a time limit of 90 seconds is placed on each query.) A maximum of 200 records will be displayed in the results tab at a time. If your query produces more that 200 records, you can page through the results by clicking the page numbers in the purple bar below the UI tabs.
Your results will appear in a table in order of ascending archive set number (SET_ID) and object number (Figure 10). To reorder the results table by another parameter, click on the column heading corresponding to that parameter. This action will automatically sort the results in ascending order. To reverse the order, click on the small arrow beneath the parameter's name in the column heading. The results table may be printed or downloaded to a file using the "Printable Version" and "Download Results" options located above the table.
In each record of the results table, the values of SET_ID and NUMBER are linked to Set Summary and Object Summary pages associated with the archive set and object, respectively. Clicking on these links will spawn pop-up windows containing the appropriate summary pages.
Any objects in the results table may be located in the drizzled and combined APSIS images by clicking the "Mark" boxes associated with those objects in the table. After marking all the desired objects, click "Object Map" in the list of functions above the results table. This action will spawn a pop-up Object Map with overlayed Kron apertures associated with only the selected objects. In this manner, the Object Map serves as a finding chart for objects listed in the results table. (Note that the Object Map displays the full image with 8x8 pixel binning, so the apertures of small objects may be difficult to identify.)
If your query fails to execute properly, you may wish to report the offending query as a possible UI bug to the SDA developers. When doing so, you should include the Structured Query Language (SQL) markup of your query in your correspondence so that the developers can quickly and easily identify the cause of the problem. To obtain the SQL markup, simply click "Show SQL" in the list of functions above the results table.
Object Summary pages allow the user to view simultaneously the images and measured characteristics of individual objects. These pages can be produced by either clicking on the images of objects in an Object Map or clicking on the object numbers in a query results table. Object Summary pages are generated on-the-fly and appear in pop-up windows.
Figure 11 shows the Object Summary page for one object listed in results of the query defined in Figures 8 and 9. The page features a table of basic information about the object culled from the detection and BPZ catalogs generated by APSIS. The page also includes a monochrome cutout image of the object from the APSIS detection image, over which the Kron aperture (determined by SExtractor) is plotted, and a three-color cutout image produced from the constituent filter images of the data set. At the bottom of the Object Summary page are monochrome cutout images from each of the filter images. Each cutout image is annotated with its appropriate filter name and calibrated photometric magnitudes. To view or download a cutout filter image as a FITS file, simply click on the desired filter image. Your browser will then query you for the details of the download.
The user may inspect the Object Summary pages of other detected objects from the associated archive set by clicking the "First," "Last," "Prev," or "Next" links at the top of the page. Links to the Data Inventory page and the Object Map for that archive set also appear at the top of the page. Clicking on the Object Map will produce a monochrome JPEG image of the entire imaged field in which the object of interest is indentified with an overplotted Kron aperture. Thus, the Object Map serves as a finding chart for the object. Note that the overplotted Kron apertures for very small objects may not be easily seen in the demagnified Object Map.
New to the Object Summary in v1.8.1 is a function that enables searches of external databases for objects up to 10 arcmin from the detected object. This function is located below the basic information table and has requires two inputs, the radius of the search and the database (SIMBAD, SDSS, NED, MAST, or GSC2) to be searched. Both inputs are supplied via drop-down menus. The search is activated when the database is selected.
Viewing a complete set of cutout, or "postage stamp," images for an individual image is best accomplished through the Object Summary page for that object. To produce an array of cutout images for several objects listed in the query results page, select the desired objects by clicking the associated "Mark" boxes or by clicking "Select All." Then click the "Image Cutouts" option, select the desired color palette, and then click "Show selected cutouts." These actions will produce a pop-up window with an array of cutout images from all APSIS detection and filter images associated with that object. The detection-image cutouts feature overlayed Kron apertures. Also provided are three-color JPEG cutouts derived from the three reddest filters in the displayed image set. The filter-image cutouts are displayed in order of ascending wavelength (Figure 12).
The cutout filter images may be downloaded to disk or viewed with a FITS viewer simply by clicking on the images in the pop-up window. To view the full complement of cutout images for a single object in the array of cutout images, click on the object number printed to the right of each group of cutout images. This action will produce an Object Summary page for that object.
The locations of objects listed in each page of the query results can be determined by clicking the "Mark" boxes of the desired objects and then clicking "Object Map" in the list of functions above the results table. These actions will produce a monochrome JPEG image of the entire imaged field in which the objects of interest are indentified by their overplotted Kron apertures. Note that the overplotted Kron apertures for very small objects may not be easily seen in the demagnified Object Map.
Problems and bugs should be reported to acs-archive@pha.jhu.edu.
Personal inquiries may be directed to:
Last modified 17 March 2003 18:20:21