The General Ring Data Catalog makes it possible to select ring data sets of all types based on a variety of geometric constraints. For example, you may quickly identify all the data sets that resolve a particular section of a ring system at radial resolution of finer than 10 km. You accomplish this by entering the appropriate values into the fields you see on the form and then clicking on the Submit Query button at the bottom of the page. After a short wait, you will see a listing of all the ring observations that match the constraints you have entered.
The Rings Node catalogs data at the level of a "ring observation," which is typically a single image, occultation profile or spectrum. Note that a single ring observation may correspond to more than one data file; for example, Voyager images are archived both in compressed and in uncompressed "browse" format. In this case, two different files would correspond to the same ring observation. On the other hand, a single image from from the Wide Field/Planetary Camera on HST contains four different images, each with its own field of view and spatial resolution. In this case, four different ring observations are archived in a single file.
The fields on this form permit the user to enter many different kinds of constraints. Entering values in different fields results in an "and" operation. For example, if you select Planet=SATURN and Spacecraft=VOYAGER_1, you will see all the Saturn data from the Voyager 1 encounter. If you leave a field blank, that particular parameter is unconstrained. Since there are so many fields on the form, it is very common for most of them to be blank.
Use the Listing type box near the bottom of the page to choose among three possible ways to display the results of a query. Match Count simply counts the number of matching ring observations in the database but does not return a list. A Summary listing returns a table of the matching ring observations in addition to the match count. This is the default. A summary listing can return up to 1000 observations at a time. A Detailed listing returns a detailed summary of every parameter for each matching observation, in addition to the match count and summary listing. A detailed listing can return up to 100 observations at a time. If you exceed the limit for either a summary or detailed listing, you can see the remaining observations by entering a number to skip over into the Skip box.
Once you made your selections, click on the Search Catalog button at the bottom of the page to submit your query. If at any time you wish to erase all of your entries in the form and start over, click on the Reset Form button.
Ordering Data
The ordering of ring data is not currently integrated into this catalog.
You may email a request for data to
Neil Heather.
We can fill requests CDROMs or for limited sets of data by
electronic transfer.
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Query listings always begin with a summary of the SQL query and the
options selected, followed by the number of matches. SQL is the
language used by the database; you do not need to understand it but, if
a query fails, please report this text to the Rings Node to help us to diagnose
the problem.
Summary listing
When the Summary listing type is selected, the user sees
the typical
Match Count listing followed by a table
of the matching observations. This is the most common type of query and
serves as the default. Only the
Query record and
Ring Observation ID are listed;
if the user needs more information, repeat the same
query while requesting a
Detailed listing.
Note that a Summary listing query is limited to 1000 matches.
If more matches are found, only the first 1000 will be shown. The
Match Count
section will list both the number of matches found and the (possibly
smaller) number listed in the table. The user can repeat the query with
a number entered into the
Skip the first _____ matches
field in order to see the additional observations.
Detailed listing
When the Detailed listing type is selected, the user sees
the typical
Match Count listing and
Summary listing first.
Following is a list of every database parameter for each matching ring
observation.
In addition, the Summary listing section has active links to each
section of the Detailed listing; simply click on the record
number in the summary to jump to the detailed information.
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In queries, four different types of matches are permitted:
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In queries, you may select an Earth base out of the given list or choose "none" to restrict your query to spacecraft data.
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In queries, you may specify a numeric range for the emission angle. Only observations for which the angle is greater than or equal to the first value and less than or equal to the second will be returned.
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In queries, you may specify a numeric range for the incidence angle. Only observations for which the angle is greater than or equal to the first value and less than or equal to the second will be returned.
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In queries, you may select the name of the instrument if you only want observations from a single instrument returned. If you leave the field blank, observations from all instruments will be returned.
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In queries, use the ring targets only? field to specify whether the query should include data specifically targeted at a planetary ring system, or else any observation that satisfies the specified constraints.
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On the query form, you may enter a variety of different constraints on the note field. The common theme is that you use these constraints to match text in the field. For example, if you have reason to believe that "F RING" appears in the note field for the observations you are interested in, you can select the observations whose notes contain this text. Simply enter the text you wish to match in the field, without quotes. Note that the search is not case-sensitive.
Four different types of matches are permitted:
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In queries, you can specify a range of observation times, and the query will return any observations that were being carried out during the interval given. Times can be entered in a broad range of formats; click here for the gory details.
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In queries, you can select a particular type from the given list, and only observations of that type will be returned. If you leave the field blank, all observation types will be returned.
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In queries, you may specify a numeric range for the phase angle. Only observations for which the phase angle is greater than or equal to the first value and less than or equal to the second will be returned.
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Using the planet field on the query form, the user can specify which of the four planets is of interest. This is probably the common field on the form to constrain. If it is left blank, observations of all four planets will be listed.
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Note that the query record number counts all matching records, regardless of the particular query options selected. For example, if the user has chosen to skip the first 100 matches, then query record values on the listing will begin with 101.
Query record values appear as the first column in a summary listing, under the heading #. When a detailed listing is requested, each # in the summary table serves as a hypertext link to the detailed information for the same observation.
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In queries, select YES if you only want observations flagged as ring observations to be returned. Select NO if this flag should be ignored in the query.
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In queries, you can specify a range of ring event times, and the query will return any observations corresponding to the interval given. Times can be entered in a broad range of formats; click here for the gory details.
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In queries, you may select observations whose IDs match a particular pattern. Four different types of matches are permitted:
Any Ring observation ID in an output listing serves as a link to a page containing a preview and more information about the data, plus links to the data files.
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In queries, you can specify a range of ring radius values, and the query will return any observations whose range of radii intersect the range requested.
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The radial resolution is the typically equal to the intrinsic point spread function of the data, as projected into the ring plane. For spectra or other data sets that have no intrinsic spatial resolution, it is equal to the difference between the maximum and minimum ring radius values.
In queries, you can specify a range of radial resolution values, and the query will return any observations whose range of radial resolutions intersects the range requested.
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In queries, you may select the spacecraft from the given list and only observations from that spacecraft will be returned. Leave the field blank if you do not wish to constrain the search in this manner. Select none to return only Earth-based observations.
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The wavelength gives the range of wavelengths observed, in microns. A triplet of values specifying the mean, minimum and maximum are associated with each ring observation.
In queries, you can specify a range of wavelength values, and the query will return any observations whose range of wavelengths intersect the range requested.
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In queries, you may specify a numeric range for the wavelength resolution. Only observations for which the resolution is greater than or equal to the first value and less than or equal to the second will be returned.
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Last updated 8 December 2000