SkyBoT name resolver

The method skybotresolver is intended to people who need to resolve the name of a Solar System object (asteroid, planet, natural satellite or comet) in celestial coordinates. This method must be used only in the framework of the SkyBoT service, in particular to resolve name in celestial coordinates for spacecrafts.

Please use instead SsODNet service to resolve the name of any Solar System object.

HTTP Request

If you are a software/solutions developer, you might want to include the SkyBoT skybotresolver service into your application. This can be done by using the web service method or by using the following HTTP request:[parameters]
where [parameters] is a list of parameters separated by the character &. The allowed parameters are:
-name=<string> Name or designation of the target Ex.: 2, Pallas, 1999 TC36, p/halley
-ep=<dateTime> Requested epoch, expressed in Julian period, ISO format,
or formatted as any English textual datetime
2411320.0 .. 2473540.0
1889-11-13 12h .. 2060-03-21 12h
-mime=<string> Mime type of the results votable | html | text | json
-observer=<string> Code or geographic coordinates of the observer's location Ex.: 500 (geocenter), 007 (Paris), @kepler, ...
-output=<string> Output parameters object | basic | obs | all
-refsys=<string> Code to indicate the reference system of coordinates EQJ2000 (default) | ECJ2000 (optional)
-from=<string> Word which define the name of the caller application,
or which describes the request
any short string
(no space character)

The output results are described in the following section, and are available in VOTable (default), HTML, plain text format, and JSON object (cf. examples). The -mime and -output arguments are optionnal and their value can be omitted (just write nothing or ...&-mime=&-output= without value). In this case, the output is the basic one displayed as VOTable.

Web service

The SkyBoT Web service provides methods based on SOAP and HTTP POST verb which allow one to interact between its own application and the SkyBoT service. Here is the useful information to invoke the SkyBoT skybotresolver method:
Web Service URI:
SOAP header:
name of the SOAP header element: clientID
SOAP header's content: array('from' => 'YourName', 'hostip'=>'')
skybotresolver (inputArray)
The input parameter of the method is an array which must contained the following parameter:
VariableTypeUnitsLimits or valuesDefaultComment
name string designation - none Name or designation of the target
epoch string dateTime 2411320.0 .. 2473540.0
1889-11-13 12h .. 2060-03-21 12h
none Requested epoch (julian period, ISO format, English textual datetime)
mime string - votable | html | text | json votable Mime type of the results
observer string - Code (IAU or special) or geographic coordinates 500 Code or geographic coordinates of the observer's location
output string - object | basic | obs | all basic Output parameters
refsys string - Code to indicate the reference
system of coordinates
EQJ2000 Equatorial (EQJ2000) or ecliptic (ECJ2000)

The output of the skybotresolver method is an object containing the following attributes:

the status of the response: flag=1 means ok; flag=0 or flag=-1 mean that an error occured
the HTTP status-code of the response (e.g. 400: bad request, 422: Unprocessable Entity, 500: internal error)
the Unix timestamp of the response which can be useful to stamp the request
a string containing the ephemeris of the requested solar system body with the parameters described in the output results section
Depending on the selected mime type, the output is formatted as:
the data are written in the IVOA standard VOTable format
the data are transformed from VOTable to HTML by XSLT processing (SkyBoT XSL style sheet)
the data are returned in plain text where each value is separated by the pipe '|' character
the data are written in a JSON object.

Query examples

Output results

The output parameters of the method is a string which contains the following information:

1 Object number (blank if unnumbered) - x x x x
2 Object name (official or preliminary designation) - x x x x
3–4 Astrometric J2000 equatorial or ecliptic coordinates at the given epoch,
relatively to the observer
α in hour, δ in deg
long and lat in deg
x x x x
5 Class - x x x x
6 Visual magnitude mag x x x x
7 Error on the position arcsec x x x x
8–9 Motion on the celestial sphere (Δα'cos(δ), Δδ) or (Δlon cos(lat), Δlat) arcsec/h   x x x
10 Distance to observer au   x x x
11 Heliocentric distance au   x x x
12 Phase angle degree     x x
13 Solar elongation degree     x x
14–19 Mean J2000 heliocentric equatorial or ecliptic position and velocity vectors
at epoch T0
au and au/d       x
20 Reference epoch of the position vector Julien Day       x

Structure of the output JSON object

When the output mime type is the JSON data-interchange format, the output of the skybotresolver method is encapsulated into a structure defined as follows (case output=all):
    "Num": {int | string}, 
    "Name": {string}, 
    "RA (deg)": {float}, 
    "DEC (deg)": {float}, 
    "Class": {string},
    "VMag (mag)": {float}, 
    "Err (arcsec)": {float}, 
    "dRA (arcsec\/h)": {float}, 
    "dDEC (arcsec\/h)": {float}, 
    "dg (ua)": {float}, 
    "dh (ua)": {float}, 
    "Phase (deg)": {float}, 
    "SunElong (deg)": {float}, 
    "position (au)": { "x": {float}, "y": {float}, "z": {float} },
    "velocity (au\/d)": { "x": {float}, "y": {float}, "z": {float} },
    "ref_epoch": {float} 

How to consume

You have two ways to use the SkyBoT web service: by writting a client to send requests to the SkyBoT server and to receive and analyze the response, or by using a command line interface and a data transfert program such as curl or wget. For that, just execute one of the following commands in a console:
$> curl "<URL>"
$> wget "<URL>"
where <URL> is described in section HTTP request.

In order to help you to invoke the SkyBoT web service, we provide some clients written in differents languages. Here are some detailed explanations to write a client with PHP and SOAP which invokes the skybotresolver method:

1/ Provide the input parameters which are mandatory for the service:

// Client's ID: provide the name of your project or organisation or yourself
$from = 'MyName';
// Input parameters
$param = array('epoch'    => 'now',
               'name'     => 'io',
               'mime'     => 'json',
               'output'   => 'object',
               'observer' => 500,
               'refsys'   => 'EQJ2000');

2/ Define the SOAP options, the namespace and the WSDL URI of SkyBoT web service:

// Enables or disables the WSDL caching feature
ini_set('soap.wsdl_cache_enabled', 1);
// SkyBoT namespace
$namespace = '';
// SkyBoT WSDL
$uriwsdl = $namespace.'/skybot.wsdl';

3/ Create a SoapClient object in WSDL mode, set the SOAP header, then call the method and catch exceptions:

try {
   // Constructs the client
   $client = new SoapClient($uriwsdl, array('exceptions'=>1));
   // SOAP header
   $header = array('from'=>$from, 'hostip'=>'', 'lang'=>'en');
   $client->__setSoapHeaders(array(new SOAPHeader($namespace, 'clientID', $header)));  
   // Call the resolver method
   $response = $client->__soapCall('skybotresolver',$param);
   // Display the results
   if ($param['mime'] == 'text') {
      header("HTTP/1.0 200");
      header("Content-Type: text/plain");
      echo "# Flag: ".$response->flag.PHP_EOL;
      echo "# Ticket: ".$response->ticket.PHP_EOL;
      $res = explode(';', $response->result);
      $nbr = count($res);
      $newkey = array_keys($res);
      for ($i=0; $i<$nbr; $i++) { echo $res[$newkey[$i]].PHP_EOL; }
    } else if ($param['mime'] == 'json') {
      header("HTTP/1.0 200");
      header("Content-Type: application/json");
      echo $response->result;
   } else {
      header("HTTP/1.0 200");
      header("Content-Type: text/xml;content=x-votable");
      echo $response->result;
catch (SoapFault $fault) 
   trigger_error("SOAP Fault: {$fault->getTraceAsString()} (faultcode: {$fault->faultcode},
                               faultstring: {$fault->faultstring})", E_USER_ERROR);