Grid object and related elements¶

The GridType definition.

sarpy.io.complex.sicd_elements.Grid.DEFAULT_WEIGHT_SIZE = 512¶

the default size when generating WgtFunct from a named WgtType.

Type:: int

class sarpy.io.complex.sicd_elements.Grid.WgtTypeType(WindowName: str = None, Parameters: ParametersCollection | Dict = None, **kwargs)¶

Bases: Serializable

The weight type parameters of the direction parameters.

WindowName: str¶

Type of aperture weighting applied in the spatial frequency domain (Krow) to yield the impulse response in the row direction. Example values - “UNIFORM”, “TAYLOR”, “UNKNOWN”, “HAMMING” Required.

Type:: str

Parameters: ParametersCollection¶

Free form parameters list. Optional.

Type:: ParametersCollection

get_parameter_value(param_name: str, default: str | None = None) → str | None¶

Gets the value (first value found) associated with a given parameter name. Returns default if not found.

Parameters:

param_name (str) – the parameter name for which to search.
default (None|str) – the default value to return if lookup fails.

Returns:

the associated parameter value, or default.

Return type:

str

classmethod from_node(node, xml_ns, ns_key=None, kwargs=None)¶

For XML deserialization.

Parameters:

node (ElementTree.Element) – dom element for serialized class instance
xml_ns (None|dict) – The xml namespace dictionary.
ns_key (None|str) – The xml namespace key. If xml_ns is None, then this is ignored. If None and xml_ns is not None, then the string default will be used. This will be recursively passed down, unless overridden by an entry of the cls._child_xml_ns_key dictionary.
kwargs (None|dict) – None or dictionary of previously serialized attributes. For use in inheritance call, when certain attributes require specific deserialization.

Return type:

Corresponding class instance

copy()¶: Create a deep copy.

classmethod from_dict(input_dict)¶

For json deserialization, from dict instance.

Parameters:: input_dict (dict) – Appropriate parameters dict instance for deserialization
Return type:: Corresponding class instance

is_valid(recursive=False, stack=False)¶

Returns the validity of this object according to the schema. This is done by inspecting that all required fields (i.e. entries of _required) are not None.

Parameters:

recursive (bool) – True if we recursively check that child are also valid. This may result in verbose (i.e. noisy) logging.
stack (bool) – Print a recursive error message?

Returns:

condition for validity of this element

Return type:

bool

log_validity_error(msg)¶

Log a validity check error message.

Parameters:: msg (str) –

log_validity_info(msg)¶

Log a validation info message.

Parameters:: msg (str) –

log_validity_warning(msg)¶

Log a validity check warning message.

Parameters:: msg (str) –

set_numeric_format(attribute, format_string)¶

Sets the numeric format string for the given attribute.

Parameters:

attribute (str) – attribute for which the format applies - must be in _fields.
format_string (str) – format string to be applied

Return type:

None

to_dict(check_validity=False, strict=False, exclude=())¶

For json serialization.

Parameters:

check_validity (bool) – Check whether the element is valid before serializing, by calling is_valid().
strict (bool) – Only used if check_validity = True. In that case, if True then raise an Exception (of appropriate type) if the structure is not valid, if False then log a hopefully helpful message.
exclude (tuple) – Attribute names to exclude from this generic serialization. This allows for child classes to provide specific serialization for special properties, after using this super method.

Returns:

dict representation of class instance appropriate for direct json serialization.

Return type:

OrderedDict

to_node(doc, tag, ns_key=None, parent=None, check_validity=False, strict=False, exclude=())¶

For XML serialization, to a dom element.

Parameters:

doc (ElementTree.ElementTree) – The xml Document
tag (None|str) – The tag name. Defaults to the value of self._tag and then the class name if unspecified.
ns_key (None|str) – The namespace prefix. This will be recursively passed down, unless overridden by an entry in the _child_xml_ns_key dictionary.
parent (None|ElementTree.Element) – The parent element. Defaults to the document root element if unspecified.
check_validity (bool) – Check whether the element is valid before serializing, by calling is_valid().
strict (bool) – Only used if check_validity = True. In that case, if True then raise an Exception (of appropriate type) if the structure is not valid, if False then log a hopefully helpful message.
exclude (tuple) – Attribute names to exclude from this generic serialization. This allows for child classes to provide specific serialization for special properties, after using this super method.

Returns:

The constructed dom element, already assigned to the parent element.

Return type:

ElementTree.Element

to_xml_bytes(urn=None, tag=None, check_validity=False, strict=False)¶

Gets a bytes array, which corresponds to the xml string in utf-8 encoding, identified as using the namespace given by urn (if given).

Parameters:

urn (None|str|dict) – The xml namespace string or dictionary describing the xml namespace.
tag (None|str) – The root node tag to use. If not given, then the class name will be used.
check_validity (bool) – Check whether the element is valid before serializing, by calling is_valid().
strict (bool) – Only used if check_validity = True. In that case, if True then raise an Exception (of appropriate type) if the structure is not valid, if False then log a hopefully helpful message.

Returns:

bytes array from ElementTree.tostring() call.

Return type:

bytes

to_xml_string(urn=None, tag=None, check_validity=False, strict=False)¶

Gets a xml string with utf-8 encoding, identified as using the namespace given by urn (if given).

Parameters:

urn (None|str|dict) – The xml namespace or dictionary describing the xml namespace.
tag (None|str) – The root node tag to use. If not given, then the class name will be used.
check_validity (bool) – Check whether the element is valid before serializing, by calling is_valid().
strict (bool) – Only used if check_validity = True. In that case, if True then raise an Exception (of appropriate type) if the structure is not valid, if False then log a hopefully helpful message.

Returns:

xml string from ElementTree.tostring() call.

Return type:

str

Bases: Serializable

The direction parameters container

UVectECF: XYZType¶

Unit vector in the increasing (row/col) direction (ECF) at the SCP pixel. Required.

Type:: XYZType

SS: float¶

Sample spacing in the increasing (row/col) direction. Precise spacing at the SCP. Required.

Type:: float

ImpRespWid: float¶

Half power impulse response width in the increasing (row/col) direction. Measured at the scene center point. Required.

Type:: float

ImpRespBW: float¶

Spatial bandwidth in (row/col) used to form the impulse response in the (row/col) direction. Measured at the center of support for the SCP. Required.

Type:: float

Sgn: int¶

Sign for exponent in the DFT to transform the (row/col) dimension to spatial frequency dimension. Must take one of the values in (1, -1). Required.

Type:: int

KCtr: float¶

Center spatial frequency in the given dimension. Corresponds to the zero frequency of the DFT in the given (row/col) direction. Required.

Type:: float

DeltaK1: float¶

Minimum (row/col) offset from KCtr of the spatial frequency support for the image. Required.

Type:: float

DeltaK2: float¶

Maximum (row/col) offset from KCtr of the spatial frequency support for the image. Required.

Type:: float

DeltaKCOAPoly: Poly2DType¶

Offset from KCtr of the center of support in the given (row/col) spatial frequency. The polynomial is a function of image given (row/col) coordinate (variable 1) and column coordinate (variable 2). Optional.

Type:: Poly2DType

WgtType: WgtTypeType¶

Parameters describing aperture weighting type applied in the spatial frequency domain to yield the impulse response in the given (row/col) direction. Optional.

Type:: WgtTypeType

WgtFunct: ndarray¶

Sampled aperture amplitude weighting function (array) applied to form the SCP impulse response in the given (row/col) direction. Must have length exactly 2. Optional.

Type:: numpy.ndarray[float64]

define_weight_function(weight_size: int = 512, populate: bool = False) → ndarray | None¶

Try to derive WgtFunct from WgtType, if necessary. This should likely be called from the GridType parent.

Parameters:

weight_size (int) – the size of the WgtFunct to generate.
populate (bool) – Overwrite any populated WgtFunct value?

Return type:

None|numpy.ndarray

get_oversample_rate() → float¶

Gets the oversample rate. Added in version 1.2.35.

Return type:: float

define_response_widths(populate: bool = False) → Tuple[float, float] | None¶

Assuming that WgtFunct has been properly populated, define the response widths. This should likely be called by GridType parent.

Parameters:: populate (bool) – Overwrite populated ImpRespWid and/or ImpRespBW?
Returns:: None or (ImpRespBw, ImpRespWid)
Return type:: None|(float, float)

estimate_deltak(x_coords: ndarray | None, y_coords: ndarray | None, populate: bool = False) → Tuple[float, float] | None¶

The DeltaK1 and DeltaK2 parameters can be estimated from DeltaKCOAPoly, if necessary. This should likely be called by the GridType parent.

Parameters:

x_coords (None|numpy.ndarray) – The physical vertex coordinates to evaluate DeltaKCOAPoly
y_coords (None|numpy.ndarray) – The physical vertex coordinates to evaluate DeltaKCOAPoly
populate (bool) – Overwite any populated DeltaK1 and DeltaK2?

Returns:

min_deltak (float)
max_deltak (float)

check_deltak(x_coords: ndarray | None, y_coords: ndarray | None) → bool¶

Checks the DeltaK values for validity.

Parameters:

x_coords (None|numpy.ndarray) – The physical vertex coordinates to evaluate DeltaKCOAPoly
y_coords (None|numpy.ndarray) – The physical vertex coordinates to evaluate DeltaKCOAPoly

Return type:

bool

copy()¶: Create a deep copy.

classmethod from_dict(input_dict)¶

For json deserialization, from dict instance.

Parameters:: input_dict (dict) – Appropriate parameters dict instance for deserialization
Return type:: Corresponding class instance

classmethod from_node(node, xml_ns, ns_key=None, kwargs=None)¶

For XML deserialization.

Parameters:

node (ElementTree.Element) – dom element for serialized class instance
xml_ns (None|dict) – The xml namespace dictionary.
ns_key (None|str) – The xml namespace key. If xml_ns is None, then this is ignored. If None and xml_ns is not None, then the string default will be used. This will be recursively passed down, unless overridden by an entry of the cls._child_xml_ns_key dictionary.
kwargs (None|dict) – None or dictionary of previously serialized attributes. For use in inheritance call, when certain attributes require specific deserialization.

Return type:

Corresponding class instance

is_valid(recursive=False, stack=False)¶

Returns the validity of this object according to the schema. This is done by inspecting that all required fields (i.e. entries of _required) are not None.

Parameters:

recursive (bool) – True if we recursively check that child are also valid. This may result in verbose (i.e. noisy) logging.
stack (bool) – Print a recursive error message?

Returns:

condition for validity of this element

Return type:

bool

log_validity_error(msg)¶

Log a validity check error message.

Parameters:: msg (str) –

log_validity_info(msg)¶

Log a validation info message.

Parameters:: msg (str) –

log_validity_warning(msg)¶

Log a validity check warning message.

Parameters:: msg (str) –

set_numeric_format(attribute, format_string)¶

Sets the numeric format string for the given attribute.

Parameters:

attribute (str) – attribute for which the format applies - must be in _fields.
format_string (str) – format string to be applied

Return type:

None

to_dict(check_validity=False, strict=False, exclude=())¶

For json serialization.

Parameters:

check_validity (bool) – Check whether the element is valid before serializing, by calling is_valid().
strict (bool) – Only used if check_validity = True. In that case, if True then raise an Exception (of appropriate type) if the structure is not valid, if False then log a hopefully helpful message.
exclude (tuple) – Attribute names to exclude from this generic serialization. This allows for child classes to provide specific serialization for special properties, after using this super method.

Returns:

dict representation of class instance appropriate for direct json serialization.

Return type:

OrderedDict

to_node(doc, tag, ns_key=None, parent=None, check_validity=False, strict=False, exclude=())¶

For XML serialization, to a dom element.

Parameters:

doc (ElementTree.ElementTree) – The xml Document
tag (None|str) – The tag name. Defaults to the value of self._tag and then the class name if unspecified.
ns_key (None|str) – The namespace prefix. This will be recursively passed down, unless overridden by an entry in the _child_xml_ns_key dictionary.
parent (None|ElementTree.Element) – The parent element. Defaults to the document root element if unspecified.
check_validity (bool) – Check whether the element is valid before serializing, by calling is_valid().
strict (bool) – Only used if check_validity = True. In that case, if True then raise an Exception (of appropriate type) if the structure is not valid, if False then log a hopefully helpful message.
exclude (tuple) – Attribute names to exclude from this generic serialization. This allows for child classes to provide specific serialization for special properties, after using this super method.

Returns:

The constructed dom element, already assigned to the parent element.

Return type:

ElementTree.Element

to_xml_bytes(urn=None, tag=None, check_validity=False, strict=False)¶

Gets a bytes array, which corresponds to the xml string in utf-8 encoding, identified as using the namespace given by urn (if given).

Parameters:

urn (None|str|dict) – The xml namespace string or dictionary describing the xml namespace.
tag (None|str) – The root node tag to use. If not given, then the class name will be used.
check_validity (bool) – Check whether the element is valid before serializing, by calling is_valid().
strict (bool) – Only used if check_validity = True. In that case, if True then raise an Exception (of appropriate type) if the structure is not valid, if False then log a hopefully helpful message.

Returns:

bytes array from ElementTree.tostring() call.

Return type:

bytes

to_xml_string(urn=None, tag=None, check_validity=False, strict=False)¶

Gets a xml string with utf-8 encoding, identified as using the namespace given by urn (if given).

Parameters:

urn (None|str|dict) – The xml namespace or dictionary describing the xml namespace.
tag (None|str) – The root node tag to use. If not given, then the class name will be used.
check_validity (bool) – Check whether the element is valid before serializing, by calling is_valid().
strict (bool) – Only used if check_validity = True. In that case, if True then raise an Exception (of appropriate type) if the structure is not valid, if False then log a hopefully helpful message.

Returns:

xml string from ElementTree.tostring() call.

Return type:

str

class sarpy.io.complex.sicd_elements.Grid.GridType(ImagePlane: str = None, Type: str = None, TimeCOAPoly: Poly2DType | ndarray | list | tuple = None, Row: DirParamType = None, Col: DirParamType = None, **kwargs)¶

Bases: Serializable

Collection grid details container

copy()¶: Create a deep copy.

classmethod from_dict(input_dict)¶

For json deserialization, from dict instance.

Parameters:: input_dict (dict) – Appropriate parameters dict instance for deserialization
Return type:: Corresponding class instance

classmethod from_node(node, xml_ns, ns_key=None, kwargs=None)¶

For XML deserialization.

Parameters:

node (ElementTree.Element) – dom element for serialized class instance
xml_ns (None|dict) – The xml namespace dictionary.
ns_key (None|str) – The xml namespace key. If xml_ns is None, then this is ignored. If None and xml_ns is not None, then the string default will be used. This will be recursively passed down, unless overridden by an entry of the cls._child_xml_ns_key dictionary.
kwargs (None|dict) – None or dictionary of previously serialized attributes. For use in inheritance call, when certain attributes require specific deserialization.

Return type:

Corresponding class instance

is_valid(recursive=False, stack=False)¶

Returns the validity of this object according to the schema. This is done by inspecting that all required fields (i.e. entries of _required) are not None.

Parameters:

recursive (bool) – True if we recursively check that child are also valid. This may result in verbose (i.e. noisy) logging.
stack (bool) – Print a recursive error message?

Returns:

condition for validity of this element

Return type:

bool

log_validity_error(msg)¶

Log a validity check error message.

Parameters:: msg (str) –

log_validity_info(msg)¶

Log a validation info message.

Parameters:: msg (str) –

log_validity_warning(msg)¶

Log a validity check warning message.

Parameters:: msg (str) –

set_numeric_format(attribute, format_string)¶

Sets the numeric format string for the given attribute.

Parameters:

attribute (str) – attribute for which the format applies - must be in _fields.
format_string (str) – format string to be applied

Return type:

None

to_dict(check_validity=False, strict=False, exclude=())¶

For json serialization.

Parameters:

check_validity (bool) – Check whether the element is valid before serializing, by calling is_valid().
strict (bool) – Only used if check_validity = True. In that case, if True then raise an Exception (of appropriate type) if the structure is not valid, if False then log a hopefully helpful message.
exclude (tuple) – Attribute names to exclude from this generic serialization. This allows for child classes to provide specific serialization for special properties, after using this super method.

Returns:

dict representation of class instance appropriate for direct json serialization.

Return type:

OrderedDict

to_node(doc, tag, ns_key=None, parent=None, check_validity=False, strict=False, exclude=())¶

For XML serialization, to a dom element.

Parameters:

doc (ElementTree.ElementTree) – The xml Document
tag (None|str) – The tag name. Defaults to the value of self._tag and then the class name if unspecified.
ns_key (None|str) – The namespace prefix. This will be recursively passed down, unless overridden by an entry in the _child_xml_ns_key dictionary.
parent (None|ElementTree.Element) – The parent element. Defaults to the document root element if unspecified.
check_validity (bool) – Check whether the element is valid before serializing, by calling is_valid().
strict (bool) – Only used if check_validity = True. In that case, if True then raise an Exception (of appropriate type) if the structure is not valid, if False then log a hopefully helpful message.
exclude (tuple) – Attribute names to exclude from this generic serialization. This allows for child classes to provide specific serialization for special properties, after using this super method.

Returns:

The constructed dom element, already assigned to the parent element.

Return type:

ElementTree.Element

to_xml_bytes(urn=None, tag=None, check_validity=False, strict=False)¶

Gets a bytes array, which corresponds to the xml string in utf-8 encoding, identified as using the namespace given by urn (if given).

Parameters:

urn (None|str|dict) – The xml namespace string or dictionary describing the xml namespace.
tag (None|str) – The root node tag to use. If not given, then the class name will be used.
check_validity (bool) – Check whether the element is valid before serializing, by calling is_valid().
strict (bool) – Only used if check_validity = True. In that case, if True then raise an Exception (of appropriate type) if the structure is not valid, if False then log a hopefully helpful message.

Returns:

bytes array from ElementTree.tostring() call.

Return type:

bytes

to_xml_string(urn=None, tag=None, check_validity=False, strict=False)¶

Gets a xml string with utf-8 encoding, identified as using the namespace given by urn (if given).

Parameters:

urn (None|str|dict) – The xml namespace or dictionary describing the xml namespace.
tag (None|str) – The root node tag to use. If not given, then the class name will be used.
check_validity (bool) – Check whether the element is valid before serializing, by calling is_valid().
strict (bool) – Only used if check_validity = True. In that case, if True then raise an Exception (of appropriate type) if the structure is not valid, if False then log a hopefully helpful message.

Returns:

xml string from ElementTree.tostring() call.

Return type:

str

ImagePlane: str¶

Defines the type of image plane that the best describes the sample grid. Precise plane defined by Row Direction and Column Direction unit vectors. Takes values in ('SLANT', 'GROUND', 'OTHER'). Required.

Type:: str

Type: str¶

str: Defines the type of spatial sampling grid represented by the image sample grid. Row coordinate first, column coordinate second:

RGAZIM - Grid for a simple range, Doppler image. Also, the natural grid for images formed with the Polar Format Algorithm.
RGZERO - A grid for images formed with the Range Migration Algorithm. Used only for imaging near closest approach (i.e. near zero Doppler).
XRGYCR - Orthogonal slant plane grid oriented range and cross range relative to the ARP at a reference time.
XCTYAT - Orthogonal slant plane grid with X oriented cross track.
PLANE - Arbitrary plane with orientation other than the specific XRGYCR or XCTYAT.

Takes values in ('RGAZIM', 'RGZERO', 'XRGYCR', 'XCTYAT', 'PLANE'). Required.

TimeCOAPoly: Poly2DType¶

Time of Center Of Aperture as a polynomial function of image coordinates. The polynomial is a function of image row coordinate (variable 1) and column coordinate (variable 2). Required.

Type:: Poly2DType

Row: DirParamType¶

Row direction parameters. Required.

Type:: DirParamType

Col: DirParamType¶

Column direction parameters. Required.

Type:: DirParamType

derive_direction_params(ImageData, populate: bool = False)¶

Populate the Row/Col direction parameters from ImageData, if necessary. Expected to be called from SICD parent.

Parameters:

ImageData (sarpy.io.complex.sicd_elements.ImageData.ImageDataType) –
populate (bool) – Repopulates any present values?

Return type:

None

check_deltak(x_coords: ndarray | None, y_coords: ndarray | None) → bool¶

Checks the validity of DeltaK values.

Parameters:

x_coords (None|numpy.ndarray) –
y_coords (None|numpy.ndarray) –

Return type:

bool

get_resolution_abbreviation() → str¶

Gets the resolution abbreviation for the suggested name.

Return type:: str

get_slant_plane_area() → float¶

Get the weighted slant plane area.

Return type:: float

Grid object and related elements¶

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