Class SatelliteTracking
java.lang.Object
org.apache.sis.io.wkt.FormattableObject
org.apache.sis.referencing.operation.transform.AbstractMathTransform
org.apache.sis.referencing.operation.transform.AbstractMathTransform2D
org.apache.sis.referencing.operation.projection.NormalizedProjection
org.apache.sis.referencing.operation.projection.SatelliteTracking
- All Implemented Interfaces:
Serializable
,Parameterized
,LenientComparable
,org.opengis.referencing.operation.MathTransform
,org.opengis.referencing.operation.MathTransform2D
Satellite-Tracking projection.
This projection has been developed in 1977 by Snyder and has no associated EPSG code.
This projection is neither conformal or equal-area, but has the property that ground tracks
for satellites orbiting the Earth with the same orbital parameters are shown as straight lines
on the map. Other properties are (Snyder 1987):
- All meridians are equally spaced straight lines. They are parallel on cylindrical form and converging to a common point on conical form.
- All parallels are straight but unequally spaced. They are parallel on cylindrical form and are concentric circular arcs on conical form.
- Conformality occurs along two chosen parallels. Scale is correct along one of these parameters on the conical form and along both on the cylindrical form.
Limitations
This map projection supports only circular orbits. The Earth is assumed spherical. Areas close to poles cannot be mapped.References
John P. Snyder., 1987. Map Projections - A Working Manual chapter 28: Satellite-tracking projections.- Since:
- 1.1
- Version:
- 1.3
- See Also:
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Nested Class Summary
Nested classes/interfaces inherited from class org.apache.sis.referencing.operation.projection.NormalizedProjection
NormalizedProjection.ParameterRole
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate final double
Sines and cosines of inclination between the plane of the Earth's Equator and the plane of the satellite orbit.private final double
Sines and cosines of inclination between the plane of the Earth's Equator and the plane of the satellite orbit.private final boolean
true
if this projection is conic, orfalse
if cylindrical or unknown.private final double
Coefficients for the Conic Satellite-Tracking Projection.private final double
Ratio of satellite orbital period (P₂) over ascending node period (P₁).private final double
Coefficients for the Conic Satellite-Tracking Projection.private static final long
For cross-version compatibility.private final double
Sines and cosines of inclination between the plane of the Earth's Equator and the plane of the satellite orbit.Fields inherited from class org.apache.sis.referencing.operation.projection.NormalizedProjection
ANGULAR_TOLERANCE, context, eccentricity, eccentricitySquared, ITERATION_TOLERANCE, LARGE_LONGITUDE_LIMIT, MAXIMUM_ITERATIONS, POLAR_AREA_LIMIT
Fields inherited from class org.apache.sis.referencing.operation.transform.AbstractMathTransform2D
DIMENSION
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Constructor Summary
ConstructorsModifierConstructorDescriptionprivate
SatelliteTracking
(Initializer initializer) Work around for RFE #4093999 in Sun's bug database ("Relax constraint on placement of this()/super() call in constructors").SatelliteTracking
(org.opengis.referencing.operation.OperationMethod method, Parameters parameters) Creates a Satellite Tracking projection from the given parameters. -
Method Summary
Modifier and TypeMethodDescriptionorg.opengis.referencing.operation.MathTransform
createMapProjection
(org.opengis.referencing.operation.MathTransformFactory factory) Returns the sequence of normalization →this
→ denormalization transforms as a whole.private double
Computes the F₁ or F₂ coefficient using Snyder equation 28-9.(package private) final String[]
Returns the names of additional internal parameters which need to be taken in account when comparing twoSatelliteTracking
projections or formatting them in debug mode.(package private) final double[]
Returns the values of additional internal parameters which need to be taken in account when comparing twoSatelliteTracking
projections or formatting them in debug mode.(package private) static Initializer
initializer
(org.opengis.referencing.operation.OperationMethod method, Parameters parameters) Work around for RFE #4093999 in Sun's bug database ("Relax constraint on placement of this()/super() call in constructors").private org.opengis.parameter.InvalidParameterValueException
Returns an exception for a latitude parameter out of range.protected void
inverseTransform
(double[] srcPts, int srcOff, double[] dstPts, int dstOff) Transforms the specified (x,y) coordinates and stores the result indstPts
(angles in radians).private double
Computes the L₀, L₁ or L₂ coefficient using Snyder equation 28-2a to 28-4a.org.opengis.referencing.operation.Matrix
transform
(double[] srcPts, int srcOff, double[] dstPts, int dstOff, boolean derivate) Projects the specified (λ,φ) coordinates and stores the result indstPts
.Methods inherited from class org.apache.sis.referencing.operation.projection.NormalizedProjection
completeWithWraparound, computeHashCode, delegate, equals, getContextualParameters, getParameterDescriptors, getParameterValues, getWraparoundLongitude, inverse, tryConcatenate, tryConcatenate, variant
Methods inherited from class org.apache.sis.referencing.operation.transform.AbstractMathTransform2D
createTransformedShape, derivative, getSourceDimensions, getTargetDimensions, transform
Methods inherited from class org.apache.sis.referencing.operation.transform.AbstractMathTransform
derivative, equals, formatTo, getDomain, hashCode, isIdentity, transform, transform, transform, transform, transform
Methods inherited from class org.apache.sis.io.wkt.FormattableObject
print, toString, toString, toWKT
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Methods inherited from interface org.opengis.referencing.operation.MathTransform
derivative, isIdentity, toWKT, transform, transform, transform, transform, transform
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Field Details
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serialVersionUID
private static final long serialVersionUIDFor cross-version compatibility.- See Also:
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cos_i
private final double cos_iSines and cosines of inclination between the plane of the Earth's Equator and the plane of the satellite orbit. The angle variable name is i in Snyder's book.- See Also:
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sin_i
private final double sin_iSines and cosines of inclination between the plane of the Earth's Equator and the plane of the satellite orbit. The angle variable name is i in Snyder's book.- See Also:
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cos2_i
private final double cos2_iSines and cosines of inclination between the plane of the Earth's Equator and the plane of the satellite orbit. The angle variable name is i in Snyder's book.- See Also:
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p2_on_p1
private final double p2_on_p1Ratio of satellite orbital period (P₂) over ascending node period (P₁).- See Also:
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n
private final double nCoefficients for the Conic Satellite-Tracking Projection. Those values areDouble.NaN
in the cylindrical case. -
s0
private final double s0Coefficients for the Conic Satellite-Tracking Projection. Those values areDouble.NaN
in the cylindrical case. -
isConic
private final boolean isConictrue
if this projection is conic, orfalse
if cylindrical or unknown.
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Constructor Details
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SatelliteTracking
public SatelliteTracking(org.opengis.referencing.operation.OperationMethod method, Parameters parameters) Creates a Satellite Tracking projection from the given parameters.- Parameters:
method
- description of the projection parameters.parameters
- the parameter values of the projection to create.- Throws:
org.opengis.parameter.InvalidParameterValueException
- if some parameters have incompatible values.
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SatelliteTracking
Work around for RFE #4093999 in Sun's bug database ("Relax constraint on placement of this()/super() call in constructors").
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Method Details
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initializer
@Workaround(library="JDK", version="1.8") static Initializer initializer(org.opengis.referencing.operation.OperationMethod method, Parameters parameters) Work around for RFE #4093999 in Sun's bug database ("Relax constraint on placement of this()/super() call in constructors"). -
createMapProjection
public org.opengis.referencing.operation.MathTransform createMapProjection(org.opengis.referencing.operation.MathTransformFactory factory) throws org.opengis.util.FactoryException Returns the sequence of normalization →this
→ denormalization transforms as a whole. The transform returned by this method expects (longitude, latitude) coordinates in degrees and returns (x,y) coordinates in metres.- Overrides:
createMapProjection
in classNormalizedProjection
- Parameters:
factory
- The factory to use for creating the transform.- Returns:
- the map projection from (λ,φ) to (x,y) coordinates.
- Throws:
org.opengis.util.FactoryException
- if an error occurred while creating a transform.- See Also:
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getInternalParameterNames
Returns the names of additional internal parameters which need to be taken in account when comparing twoSatelliteTracking
projections or formatting them in debug mode.- Overrides:
getInternalParameterNames
in classNormalizedProjection
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getInternalParameterValues
final double[] getInternalParameterValues()Returns the values of additional internal parameters which need to be taken in account when comparing twoSatelliteTracking
projections or formatting them in debug mode.- Overrides:
getInternalParameterValues
in classNormalizedProjection
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F
Computes the F₁ or F₂ coefficient using Snyder equation 28-9. Note that this is the same equation than F₁′ in above cylindrical case, but with the addition of arc-tangent. This value is constant after construction time.- Parameters:
cos2_φ
- square of cosine of φ₁ or φ₂.source
- description of φ argument. Used for error message only.- Returns:
- F coefficient for the given φ latitude.
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L
Computes the L₀, L₁ or L₂ coefficient using Snyder equation 28-2a to 28-4a. This value is constant after construction time.- Parameters:
sinφ
- sine of φ₀, φ₁ or φ₂.source
- description of φ argument. Used for error message only.- Returns:
- L coefficient for the given φ latitude.
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invalid
private org.opengis.parameter.InvalidParameterValueException invalid(org.opengis.parameter.ParameterDescriptor<Double> source) Returns an exception for a latitude parameter out of range. The range is assumed given by satellite orbit inclination.- Parameters:
source
- description of invalid φ argument.
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transform
public org.opengis.referencing.operation.Matrix transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, boolean derivate) throws ProjectionException Projects the specified (λ,φ) coordinates and stores the result indstPts
. In addition, opportunistically computes the projection derivative ifderivate
istrue
. The units of measurement are implementation-specific (see super-class javadoc). The results must be multiplied by the denormalization matrix before to get linear distances.The y axis lies along the central meridian λ₀, y increasing northerly, and x axis intersects perpendicularly at latitude of origin φ₀, x increasing easterly.
- Specified by:
transform
in classNormalizedProjection
- Parameters:
srcPts
- the array containing the source point coordinates, as (longitude, latitude) angles in radians.srcOff
- the offset of the single coordinate tuple to be converted in the source array.dstPts
- the array into which the converted coordinates is returned (may be the same thansrcPts
). Coordinates will be expressed in a dimensionless unit, as a linear distance on a unit sphere or ellipse.dstOff
- the offset of the location of the converted coordinates that is stored in the destination array.derivate
-true
for computing the derivative, orfalse
if not needed.- Returns:
- the matrix of the projection derivative at the given source position,
or
null
if thederivate
argument isfalse
. - Throws:
ProjectionException
- if the coordinates cannot be converted.- See Also:
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inverseTransform
protected void inverseTransform(double[] srcPts, int srcOff, double[] dstPts, int dstOff) throws ProjectionException Transforms the specified (x,y) coordinates and stores the result indstPts
(angles in radians).- Specified by:
inverseTransform
in classNormalizedProjection
- Parameters:
srcPts
- the array containing the source point coordinates, as linear distance on a unit sphere or ellipse.srcOff
- the offset of the point to be converted in the source array.dstPts
- the array into which the converted point coordinates is returned (may be the same thansrcPts
). Coordinates will be (longitude, latitude) angles in radians.dstOff
- the offset of the location of the converted point that is stored in the destination array.- Throws:
ProjectionException
- if the coordinates cannot be converted.
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