By default the 'Data Retrieval' section of the web page will include a simple Cone Search form where users can search for catalogue entries around a given point in the sky (RA and DEC) and within a search radius (SR).
But you have the option to configure your service so that users can restrict searches using other catalogue fields.
For each field (except RA and DEC, that are always required) you can set the 'Search' column to "Yes" and it will be optionally allowed for searches.
If you mark a field as "Yes", you must also set the "Search type" and "Form Type" to specify how this field should be used.
You must set this configuration values wisely. For instance:
In our case we have allowed to restrict searches using the spectral type. Now the search form will show the corresponding entry for this field and users can restrict the results to those with a particular spectral type, for instance, L1.5 (just an example)::
you can see that the list of results has changed. Now there are only 3 objects objects with this spectral type.
In the case that your catalogue contains photometry values, an special form can be included to search for magnitude and colors ranges.
Object Name/Target search
In the case that your catalogue contains astronomical objects you could want to configure special options to allow for alternative object names using Simbad information.
When a user first accesses the 'Data retrieval' section it is usual to show, at least, a part of the catalogue by default. This means performing a "Default search" and showing the results of this search.
You can configure here if you want to show the catalogue as default, how many results you want to show and if you want to add some restrictions to the default search.
In our example catalogue, that is very small, we have chosen to show all the results sorted by the object name (oby=name).
But you can include more restrictions. For instance, you can ask to show only entries with L8 spectral type:
and the default result would include that restriction:
Other search options
In this section you can allow to make searches without using RA,DEC coordinates. This is necessary for catalogues that do not contain RA,DEC and is also useful for catalogues where you expect that the most interesting queries will be made in terms of other columns.
In the search page you can specify some special listings for catalogue entries with certain properties. These will appear as links so that, when the user clicks on of them, a search will be done and the corresponding results will be shown. To do this you must specify the text that will appear highlighted and the restrictions in terms of the database fields (only for database fields that have been configured above as available for search, that is, in this case, the spectral type (opspty).
In our example catalogue this does not make much sense because it is very small. But we could, for instance, define a link as:
That, if clicked, would produce a list of objects with spectral type = L8.
Search options in ConeSearch
Although the VO ConeSearch protocol only specifies that RA/DEC/SR must be the search criteria, it does not forbid to restrict searches using other catalogue fields.
In our particular implementation of ConeSearch all the search restrictions that are allowed for the web page are also allowed for the ConeSearch queries.
In order to make these options public, we have implemented a 'format=metadata' option in the same way as it is specified in the SSA protocol:
(where, remember, http://www.mylab.org/catalogues/excat2/ should be the main URL that corresponds to your installation)
There, among other things, the list of parameters allowed for queries are specified in the usual fashion (and the available range or list of possible values when appropriate).
so that valid queries to the catalogue ConeSearch service could be, for instance:
depending on how the user wants to restrict the query.