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Field Of Observation

Implements : CzmlPrimaryObject

Extends : AbstractPrimaryObject

The field of observation build several packet containing a polyline and two positions built with references, this way :

  {
    "id":"org.orekit.czml.CzmlObjects.Polyline@7c9d8e2",
    "name":"Line of the Line of observation : org.orekit.czml.CzmlObjects.Polyline@7c9d8e2",
    "polyline":{
      "width":2,
      "arcType":"NONE",
      "material":{
        "solidColor":{
          "color":{
            "rgba":[
              0,255,255,255
            ]
          }
        }
      },
      "positions":{
        "references":[
          "Keplerian parameters: {a: 7878000.0; e: 0.0; i: 20.0; pa: 0.0; raan: 0.0; v: 0.0;}#position",
          "ABSTRACT_POINT_ON_BODY/[{lat: -4,5845675037 deg, lon: -171,0701154498 deg, alt: 0}, {lat: -3,5178931538 deg, lon: -168,409426159 deg, alt: 0}, {lat: -2,4558877473 deg, lon: -165,750304038 deg, alt: 0}, {lat: -1,4012978714 deg, lon: -163,0907519092 deg, alt: 0}, {lat: -0,3568567738 deg, lon: -160,4288190597 deg, alt: 0}, {lat: 0,6747168422 deg, lon: -157,762618354 deg, alt: 0}, {lat: 1,6907171097 deg, lon: -155,0903341517 deg, alt: 0}, {lat: 2,6884500076 deg, lon: -152,4102346192 deg, alt: 0}, {lat: 3,6652453502 deg, lon: -149,7207033519 deg, alt: 0}, {lat: 4,6184547461 deg, lon: -147,0202399812 deg, alt: 0}]#position"
        ]
      }
    }
  }

Properties

id - String : Identification of the Field Of Observation - default : "LINE_OBSERVATION/{Id of the fov}"

name - String : Name of the Field Of Observation, default : "Line of observation of : {name of the satellite}".

availability - TimeInterval : Time interval when the Field Of Observation is displayed.

Intrinsinc arguments

These arguments can be used to build a attiude pointing object :

satellite - Satellite : The satellite which field of view is defined

fieldOfView - FieldOfView : The field of view object of the satellite

fovToBodyInput - Transform : The orekit Transform object transforming the frame from the LOF to the body.

color - Color : The color of the lines defining the field of view, default : cyan

body - OneAxisEllipsoid : The body around which the satellite orbits, default : earth

angularStep - double : Angular precision of the point projected on the ground to compute the field of observation. A higher angular precision will mean a higher number of lines displayed and a higher number of sides of the field computed.

Other parameters

referenceSatellite - Reference : The reference of the satellite, used for the position.

groundReferences - List of Reference : The list of all the references of the points on the ground computed to represents the field of view.

initialFootprints - List of List of GeodeticPoint : A list of all the geodetic points, they correspond either to projection on ground of the edges of the Field Of View, or to points on the body limb if the Field Of View goes past horizon.

allPoints - List of AbstractPointOnBody : A list of all the abstract points on body computed from the geodetic points.

polylineColor - Color : The color of the polylines.

julianDates - List of JulianDate : A list of all the julian dates where the field of observation is computed.

cartesianListFootprint - List of List of List of Cartesian : A list that contains all the cartesians of all the footprints in time.

Build

The field of observation object can be build with :

• A satellite, a fieldOfView, a fovToBodyInput :

FieldOfObservation fieldOfObservation = new FieldOfObservation(satellite, fieldOfView, fovToBodyInput);

• A satellite, a fieldOfView, a fovToBodyInput, a Color :

FieldOfObservation fieldOfObservation = new FieldOfObservation(satellite, fieldOfView, fovToBodyInput, color);

• A satellite, a fieldOfView, a fovToBodyInput, body :

FieldOfObservation fieldOfObservation = new FieldOfObservation(satellite, fieldOfView, body);

• A satellite, a fieldOfView, a fovToBodyInput, body, a Color :

FieldOfObservation fieldOfObservation = new FieldOfObservation(satellite, fieldOfView, body, color);

• A satellite, a fieldOfView, a fovToBodyInput, body, an angularStep, a Color :

FieldOfObservation fieldOfObservation = new FieldOfObservation(satellite, fieldOfView, body, angularStep, color);