Data Seeker Help Page

Use DataSeeker to query for a specific set of data from the Chandra Average Databases. Specify your data search using a three stage interface. The final output comes in the form of a fits table.

The first two search stages describe observation and spacecraft state. DataSeeker will find time intervals that match this state if they exist. The third stage defines the output table. DataSeeker will pull the requested data from the MTA Average Databases to populate the table.

You can maneuver through DataSeeker's interface by using either the "Next" buttons or the top navigation bar provided on each page.

Primary Search

The Primary Search represents the most requested search criteria. DataSeeker will find time intervals that match the input. Be sure to specify at least a Time Start and a Time Stop value here. DataSeeker will not let you move past Primary Search unless these are provided.

DataSeeker's primary search criteria is composed of the following.

Time Start:
Time start for data. Enter in any of the following formats
SECS Elapsed seconds since 1998-01-01T00:00:00
DATE YYYY:DDD:hh:mm:ss.ss...
CALDATE YYYYMonDD at hh:mm:ss.ss...
FITS date/time format YYYY-MM-DD or YYYY-MM-DDThh:mm:ss.ss...
DataSeeker automatically determines which time format is being used. eg. timestart=2001:301:10:30:29 is the same as timestart=2001Oct28 at 10:30:29 is the same as timestart=120652229.
Time end:
Time end for data. Same format as Time Start
Obs ID:
The observation identification number.
Right Ascension (RA):
The ra component of the spacecraft's attitude. Provide a range (From - To) for this value. Can be specified as either decimal degrees or hh mm ss or hh:mm:ss with the ss portion being optional. eg: 180 is the same as 12:00:00 is the same as 12 00 00 is the same as 12 00
Declination (Dec):
The dec component of the spacecraft's attitude. Provide a range (From - To) for this value. Same format as RA.
Roll (Roll):
The roll component of the spacecraft's attitude. Provide a range (From - To) for this value. Specify in decimal degrees.
Science Instrument (si):
The Science Instrument being used.
Grating (grating):
The Grating being used.
SC Altitude
Spacecraft altitude in meters.
CRMREG
Chandra Radiation Model, 1=WIND, 2=MAGNETOSHEATH, 3=MAGNETOSPHERE

Secondary Search

DataSeeker's secondary search refines the time intervals found in the primary search by checking against values in the MTA Configuration Databases. Select values using the pull down menus for each mnemonic.

Set Output

DataSeeker's Set Output page defines the final output table using the time intervals determined from the primary and secondary searches. Check the tables you want to pull data from. If you want to pull these tables as is for the final output, simply click the "Get Table(s)" radio button and hit the ">>Next" button. Otherwise, select "Set Indiv. MSIDS" and click ">>Next" to proceed to the column selection page.

On the column selection page, select the individual columns you want returned. Each msid (mnemonic string id) has three retrievable columns: <msid>_avg (average value), <msid>_std (standard deviation), and <msid>_lim (status flags). Check the msid itself at the left to get all three for that msid. Click the "table" box on top to get the entire table, or the _avg, _lim, _std boxes to get only the _avg, _lim, or _std values from the table.

If you select the full table in either the table selection or column selection pages, there will be an additional Navg column in the output dataset. Navg is the number of samples used to determine the averages for each row in each table. If there are more than one table in the output dataset the Navg column will be named Navg_<tablename>.

Now click the "Get Data" button or the "Get Data" image in the top navigation bar to get your final data set.

Get Data

Be warned, retrieving data can take anywhere from 10 seconds to an hour depending on the size of the search range and the number of tables selected for output. DataSeeker's table merging process can be time consuming.

DataSeeker's Get Data page provides you with access to your output dataset. You can retrieve your dataset as either a FITS file or an ASCII RDB file. If you want to download your dataset, be sure to either Shift+Click the link or RightClick->SaveLinkAs. Otherwise the output will spill out into the browser window.

The Get Data page also provides a link to "Get DS Criteria". This link will retrieve the search criteria defining your output in a format acceptable to Command Line DataSeeker. Feed this file as input to Command Line DataSeeker to perform the same search or edit it to modify your search.

Get Times

At any time in DataSeeker's criteria specification process, you can hit the "Get Times" button in the left-hand column of the page. This will perform DataSeeker's search. DataSeeker will retrieve time ranges satisfying your current search and display them in a pop-up "TV" window and at the bottom of the left-hand column. The time ranges will disappear from the left-hand column when the search criteria changes, rendering them obsolete.