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JplSpkFile Class

Provides raw access to a JPL Spacecraft and Planet Kernel (SPK) file, which typically uses a binary *.bsp extension.
Inheritance Hierarchy

Namespace:  AGI.Foundation.Spice
Assembly:  AGI.Foundation.Models (in AGI.Foundation.Models.dll) Version: 24.2.419.0 (24.2.419.0)
Syntax
public class JplSpkFile : DefinitionalObject

The JplSpkFile type exposes the following members.

Constructors
  NameDescription
Public methodJplSpkFile(StreamFactory)
Initializes a new instance with the specified stream factory.
Public methodJplSpkFile(String)
Initializes an instance using the specified JPL SPK filename.
Protected methodJplSpkFile(JplSpkFile, CopyContext)
Initializes a new instance as a copy of an existing instance.
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Properties
  NameDescription
Public propertyIsFrozen
Gets a value indicating whether this object is frozen. A frozen object cannot be modified and an ObjectFrozenException will be thrown if an attempt is made to do so.
(Inherited from DefinitionalObject.)
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Methods
  NameDescription
Protected methodCheckForSameDefinition(DefinitionalObject)
Checks to determine if another instance has the same definition as this instance and returns if it does. Derived classes MUST override this method and check all new fields introduced by the derived class for definitional equivalence. It is NOT necessary to check base class fields because the base class will already have done that. When overriding this method, you should NOT call the base implementation because it will return for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IsSameDefinition(Object).
(Overrides DefinitionalObjectCheckForSameDefinition(DefinitionalObject).)
Protected methodCheckForSameDefinition(JplSpkFile)
Checks to determine if another instance has the same definition as this instance and returns if it does. Derived classes MUST override this method and check all new fields introduced by the derived class for definitional equivalence. It is NOT necessary to check base class fields because the base class will already have done that. When overriding this method, you should NOT call the base implementation because it will return for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IsSameDefinition(Object).
Public methodClone
Clones this object using the specified context.
(Overrides DefinitionalObjectClone(CopyContext).)
Protected methodComputeCurrentDefinitionHashCode
Computes a hash code based on the current properties of this object. Derived classes MUST override this method and compute a hash code that combines: a unique hash code seed, the base implementation result, and the hash codes of all new fields introduced by the derived class which are used in the CheckForSameDefinition(DefinitionalObject) method.
(Overrides DefinitionalObjectComputeCurrentDefinitionHashCode.)
Public methodEnumerateDependencies
Enumerates the dependencies of this object by calling EnumerateT(T) for each object that this object directly depends upon. Derived classes which contain additional dependencies MUST override this method, call the base implementation, and enumerate dependencies introduced by the derived class.
(Inherited from DefinitionalObject.)
Public methodEquals
Determines whether the specified object is equal to the current object.
(Inherited from Object.)
Protected methodFinalize
Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.
(Inherited from Object.)
Public methodFreeze
Freezes this object. Further attempts to modify it will result in an ObjectFrozenException.
(Inherited from DefinitionalObject.)
Protected methodFreezeAggregatedObjects
Called by Freeze to also freeze any objects that are considered to be a part of this object. Derived classes which contain additional aggregated objects MUST override this method, call the base implementation, and freeze aggregated objects introduced by the derived class. The objects that need to be frozen in this method are frequently created in this object's constructor and are not settable via properties.
(Inherited from DefinitionalObject.)
Public methodGetDefinitionHashCode
Gets a hash code representing the definition of this object.
(Inherited from DefinitionalObject.)
Public methodGetHashCode
Serves as the default hash function.
(Inherited from Object.)
Public methodGetNaifIdsOfAvailableTargetPointsAndCenterPoints
Interrogates a .bsp file to ascertain which target points are available and what center points they are modeled to orbit around. The NAIF website is a good reference for how JPL defines CentralBodies and other points as NAIF ID codes.
Public methodGetTargetPoint(IProvideNaifIdCode, IProvideNaifIdCode)

Gets a point describing the position of a target location with respect to a center location.

This overload requires that the centerPointProvider is a CentralBody, PlanetarySystemBarycenter, or SolarSystemBarycenter. The currently configured center of mass point of the centerPointProvider will then be used to locate the output point.

Public methodGetTargetPoint(Int32, Int32, Point)
Gets a point describing the position of a target location with respect to a center location.
Public methodGetTargetPoint(IProvideNaifIdCode, IProvideNaifIdCode, Point)
Gets a point describing the position of a target location with respect to a center location.
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Public methodIsSameDefinition
Determines if this object has the same definition as another object.
(Inherited from DefinitionalObject.)
Protected methodMemberwiseClone
Creates a shallow copy of the current Object.
(Inherited from Object.)
Protected methodThrowIfFrozen
Throws ObjectFrozenException if this object IsFrozen. This method should be called from any method or property that modifies this object.
(Inherited from DefinitionalObject.)
Public methodToString
Returns a string that represents the current object.
(Inherited from Object.)
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Remarks

If STK is installed with the Planetary Data Supplement, several relatively small (less than 200 MB each) *.bsp files are available in the STKData/Spice folder of the STK installation. These files are described in the Readme.txt file in the ReadMe folder inside the STKData/Spice folder. They provide enough data to enable all of the available CentralBodies and PlanetarySystemBarycenters to have their CenterOfMassPoints be defined in terms of the SolarSystemBarycenter within the CentralBodiesFacet with far greater accuracy and precision than the default analytic ephemeris can provide.

If STK or the Planetary Data Supplement are unavailable, the next best option is to go to the website of the Navigation and Ancillary Information Facility (NAIF) of JPL to download *.bsp ephemerides for planets and planetary moons. Some of these can be massive (greater than 1 GB) because they often contain data that extends hundreds of years into the past and future for astronomical purposes. There is typically a small text *.cmt file with the same name as the *.bsp ephemeris that contains information about what data is contained within each *.bsp file.

For asteroids and comets, the best strategy is to go to the website of the Solar System Dynamics (SSD) group of JPL to generate custom *.bsp files using the Horizons Web Application.

See Also