How to do?

SsODNet . resolver

High level name resolver

What should I use: SsODNet.quaero or SsODNet.resolver?

Both methods provide equivalent results.

SsODNet.quaero is the core engine of SsODNet. Its REST API allows to search for objects via a query string “mini-language”. The output response is formatted in the JSON data-interchange format. SsODNet.quaero is dedicated to developers who want to implement a solar system object resolver in their application (search for objects, name auto completion). Read quaero documentation for more information.

SsODNet.resolver is the top-level application dedicated to users. It allows to search for objects and to retrieve theirs coordinates in a single request. The output response is written in various format (VOTable, JSON, text). Its Web service API can also be used to implement a service on the client side.

How names are resolved?

The names of solar system objects or extrasolar planets are cross-matched with the knowledge database of SsODNet through the SsODNet.quaero API, which allows atomic and full-text search. The celestial coordinates of objects are obtained by computation of their ephemerides at a given epoch through a request to the Miriade.ephemcc Web service. The coordinates of exoplanets are requested to the database of The Extrasolar Planets Encyclopaedia through its TAP service. The celestial coordinates of spacecrafts and spacejunks orbiting the Earth are computed through Miriade by using the dedicated FAST software [implementation in progress].

How to name objects?

The resolution of the name of a solar system object or an extrasolar planet can be achieved from its official or provisional designation, or its number. The general syntaxe to request objects in SsODNet.resolver is the following:

[<prefix>:][<operator>:]<name>

where <prefix> is one of the target types defined in the SsODNet data-model, where <operator> is one of the recognized operators: EQUAL (or =), LIKE or EXPR, and where <name> is the number or the official or provisionnal designation of the target.

The prefix and operator elements can be ommitted. In this case the name of the target is matched considering its name among all the known objects by string matching, which is case-insensitive, uses the UTF-8 set of characters, and ignores trailing blanks (space, tab and new line) and underscore. For example, a request -name=SsoName will search for a target with name or alias equal to SsoName.

Examples:

Prefix

By adding a prefix to the name, the search can be limited to a given type of target. The list of possible values of <prefix> is as follows:

a Asteroid p Planet
c Comet s Satellite
dpDwarf planetscSpacecraft
e Exoplanet sjSpacejunk
Examples:

The special prefix id can also be used to resolve the true name of a target, i.e. the name given in the id field of the response.

Examples:

Operator

By default, the SSO name search is not case sensitive. The EQUAL operator allows you to make the search case sensitive. This can be useful for searching for extended packed numbers, e.g. a0000 vs A0000. Without an operator both objects will be retrieved by the search. The EQUAL operator allows you to retrieve only the one that is requested.

Examples:

To search for a target based on part of its name, use the LIKE operator. In this case, the name is divided into elements that are matched against the names and aliases in the SsODNet index. You can also use a prefix to limit the search to a specific type of object.

Examples:

The EXPR operator can be used to build complex queries incorporating wildcards, regular expressions, fuzzy terms, etc. In this case, the name part of the query is sent to the SsODNet.quaero engine in order to match the expression to a pattern, search for similar terms, exclude names, etc. This type of query should be used with caution as it can be particularly heavy, especially if you request the celestial coordinates of objects.

For example, a query based on the pattern "EXPR:1998 ax4" retrieves more than 30,000 objects! Note that with the EXPR operator, the prefix is not decoded. Therefore, to limit the search to a given type of objects, this type must be explicitly specified in the query.

Examples:

For more information on how to compose queries, see the Extended search section of SsODNet.quaero documentation.

How to define the epoch?

The epoch must be formatted as a textual english date (in accordance with the GNU syntax of dates), or a julian day or an ISO 8601 date.

Examples (non exhaustive) of valid dates:

  • now
  • 2006-01-27T1:53:34
  • 2453762.529467592
  • 10 September 2000
  • +1 day
  • +1 week 2 days 4 hours 2 seconds
  • next Thursday
  • last Monday

The ephemeris of a Sso can be computed at any epoch in the period 973-06-04 12h (2076601.0) to 3026-07-25 12h (2826489.0). The timescale is UTC.

Restriction: the seconds must be an integer number in the ISO format. For a time resolution better than a second, please use the julian period.

Tolerance: the character 'T' of the ISO 8601 format can be omitted.