JplSpkFile Class

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

Inheritance Hierarchy

SystemObject
AGI.Foundation.InfrastructureDefinitionalObject
AGI.Foundation.SpiceJplSpkFile

Namespace: AGI.Foundation.Spice
Assembly: AGI.Foundation.Models (in AGI.Foundation.Models.dll) Version: 24.3.420.0 (24.3.420.0)

Syntax

C++

Copy

public class JplSpkFile : DefinitionalObject

Public Class JplSpkFile
	Inherits DefinitionalObject

public ref class JplSpkFile : public DefinitionalObject

type JplSpkFile =  
    class
        inherit DefinitionalObject
    end

The JplSpkFile type exposes the following members.

Constructors

	Name	Description
	JplSpkFile(StreamFactory)	Initializes a new instance with the specified stream factory.
	JplSpkFile(String)	Initializes an instance using the specified JPL SPK filename.
	JplSpkFile(JplSpkFile, CopyContext)	Initializes a new instance as a copy of an existing instance.

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Properties

	Name	Description
	IsFrozen	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

	Name	Description
	CheckForSameDefinition(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).)
	CheckForSameDefinition(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).
	Clone	Clones this object using the specified context. (Overrides DefinitionalObjectClone(CopyContext).)
	ComputeCurrentDefinitionHashCode	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.)
	EnumerateDependencies	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.)
	Equals	Determines whether the specified object is equal to the current object. (Inherited from Object.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
	Freeze	Freezes this object. Further attempts to modify it will result in an ObjectFrozenException. (Inherited from DefinitionalObject.)
	FreezeAggregatedObjects	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.)
	GetDefinitionHashCode	Gets a hash code representing the definition of this object. (Inherited from DefinitionalObject.)
	GetHashCode	Serves as the default hash function. (Inherited from Object.)
	GetNaifIdsOfAvailableTargetPointsAndCenterPoints	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.
	GetTargetPoint(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.
	GetTargetPoint(Int32, Int32, Point)	Gets a point describing the position of a target location with respect to a center location.
	GetTargetPoint(IProvideNaifIdCode, IProvideNaifIdCode, Point)	Gets a point describing the position of a target location with respect to a center location.
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	IsSameDefinition	Determines if this object has the same definition as another object. (Inherited from DefinitionalObject.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	ThrowIfFrozen	Throws ObjectFrozenException if this object IsFrozen. This method should be called from any method or property that modifies this object. (Inherited from DefinitionalObject.)
	ToString	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.

Reference

AGI.Foundation.Spice Namespace