Tabulated-Flat Spectra, external Spectral Lookup, unknown bin widths

<?xml version="1.0" encoding="UTF-8"?>
<?xml-model href="https://pds.nasa.gov/pds4/pds/v1/PDS4_PDS_1L00.sch" schematypens="http://purl.oclc.org/dsdl/schematron"?>
<?xml-model href="https://pds.nasa.gov/pds4/sp/v1/PDS4_SP_1L00_1320.sch" schematypens="http://purl.oclc.org/dsdl/schematron"?>

<!--
    This "label" is intended only to demonstrate how to use certain features of the Spectral
    Dictionary, and pretty much nothing else. It is not a real label in any sense, even though
    it should produce no errors when validated against the PDS schema. A real label would have
    references to additional dictionaries, for example, from the mission, for geometry, and/or
    for any other related discipline or local namespaces. Any "data" you see here is fictitious,
    and provided merely to remove any validation errors that might otherwise occur.

    Note, in particular, that any conscientious reviewer would consider the data structure classes
    to be inadequate without appropriate descriptions, extrema, null data indicators, and similar
    essential metadata.

    This label demonstrates:
       - Using <sp:Spectral_Characteristics> for a spectral table in the "Tabulated-Flat" fornat;
       - Using the <sp:Rectangular_FOV> to describe the aperture; and
       - Using the <sp:Spectral_Lookup> class to identify bin centers in a separate PDS product
         reference by LIDVID; and
       - Indicating an "unknown" bin width.
-->

<Product_Observational xmlns="http://pds.nasa.gov/pds4/pds/v1"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:sp="http://pds.nasa.gov/pds4/sp/v1"
    xsi:schemaLocation="http://pds.nasa.gov/pds4/pds/v1 https://pds.nasa.gov/pds4/pds/v1/PDS4_PDS_1L00.xsd
                        http://pds.nasa.gov/pds4/sp/v1  https://pds.nasa.gov/pds4/sp/v1/PDS4_SP_1L00_1320.xsd">
    <Identification_Area>
        <logical_identifier>urn:nasa:pds:bundle:collection:product</logical_identifier>
        <version_id>1.0</version_id>
        <title>Test Label 1 for Spectral Dictionary - Valid Label</title>
        <information_model_version>1.21.0.0</information_model_version>
        <product_class>Product_Observational</product_class>
    </Identification_Area>

    <Observation_Area>
        <Time_Coordinates>
            <start_date_time xsi:nil="true" nilReason="inapplicable"/>
            <stop_date_time xsi:nil="true" nilReason="inapplicable"/>
        </Time_Coordinates>

        <Investigation_Area>
            <name>None</name>
            <type>Individual Investigation</type>
            <Internal_Reference>
                <lid_reference>urn:nasa:pds:context:investigation:individual.none</lid_reference>
                <reference_type>data_to_investigation</reference_type>
            </Internal_Reference>
        </Investigation_Area>
        <Observing_System>
            <Observing_System_Component>
                <name>None</name>
                <type>Telescope</type>
            </Observing_System_Component>
        </Observing_System>
        <Target_Identification>
            <name>None</name>
            <type>Comet</type>
        </Target_Identification>

        <Discipline_Area>

            <!-- Unknown bin widths in a Spectral_Lookup referencing an external product-->

            <sp:Spectral_Characteristics>
                <Local_Internal_Reference>
                    <local_identifier_reference>TabFlat</local_identifier_reference>
                    <local_reference_type>spectral_characteristics_to_table_object</local_reference_type>
                </Local_Internal_Reference>
                <sp:spectrum_format>Tabulated-Flat</sp:spectrum_format>
                <sp:value_field_number_list>(2,3,4,5)</sp:value_field_number_list>
                <sp:spectral_bin_type>frequency</sp:spectral_bin_type>
                <sp:Field_of_View>
                    <sp:description>Simple square field of view</sp:description>
                    <sp:Rectangular_FOV>
                        <sp:width_angle unit="arcsec">5</sp:width_angle>
                        <sp:length_angle unit="arcsec">5</sp:length_angle>
                    </sp:Rectangular_FOV>
                </sp:Field_of_View>
                <sp:Bin_Description>
                    <sp:bin_profile_description>
                        Bin centers were determined during initial calibration and reported
                        in the referenced document.

                        Bin widths are as yet unknown, but are expected to be provided as part
                        final calibration.
                    </sp:bin_profile_description>
                    <sp:Spectral_Lookup>
                        <sp:Bin_Center_Lookup>
                            <Internal_Reference>
                                <lidvid_reference>urn:nasa:pds:bundle:collection:bincenters::1.0</lidvid_reference>
                                <reference_type>spectral_characteristics_to_bin_center_values</reference_type>
                            </Internal_Reference>
                        </sp:Bin_Center_Lookup>
                        <sp:Bin_Width_Constant>
                            <sp:bin_width_frequency unit="Hz" xsi:nil="true" nilReason="unknown"/>
                        </sp:Bin_Width_Constant>
                    </sp:Spectral_Lookup>
                </sp:Bin_Description>
            </sp:Spectral_Characteristics>

        </Discipline_Area>
    </Observation_Area>

    <File_Area_Observational>
        <File>
            <file_name>No.Data</file_name>
        </File>

        <!-- Tabulated-Flat Spectra -->

        <Table_Character>
            <name>Flat Spectra Table</name>
            <local_identifier>TabFlat</local_identifier>
            <offset unit="byte">0</offset>
            <records>1000</records>
            <description>
                In this format, each row of the table contains a single spectrum, and the fields (columns) are defined without
                the use of "Group_Field" classes.  This spectrum has only 4 points, and the bin parameters will be specified
                as part of the Spectral Characteristics.
            </description>
            <record_delimiter>Carriage-Return Line-Feed</record_delimiter>
            <Record_Character>
                <fields>5</fields>
                <groups>0</groups>
                <record_length unit="byte">82</record_length>

                <Field_Character>
                    <name>Target Name</name>
                    <field_number>1</field_number>
                    <field_location unit="byte">1</field_location>
                    <data_type>ASCII_String</data_type>
                    <field_length unit="byte">19</field_length>
                    <field_format>%-19s</field_format>
                </Field_Character>

                <Field_Character>
                    <name>Point 1 Value</name>
                    <field_number>2</field_number>
                    <field_location unit="byte">20</field_location>
                    <data_type>ASCII_Integer</data_type>
                    <field_length unit="byte">4</field_length>
                    <field_format>%4d</field_format>
                    <unit>DN</unit>
                </Field_Character>

                <Field_Character>
                    <name>Point 2 Value</name>
                    <field_number>3</field_number>
                    <field_location unit="byte">35</field_location>
                    <data_type>ASCII_Integer</data_type>
                    <field_length unit="byte">4</field_length>
                    <field_format>%4d</field_format>
                    <unit>DN</unit>
                </Field_Character>

                <Field_Character>
                    <name>Point 3 Value</name>
                    <field_number>4</field_number>
                    <field_location unit="byte">50</field_location>
                    <data_type>ASCII_Integer</data_type>
                    <field_length unit="byte">4</field_length>
                    <field_format>%4d</field_format>
                    <unit>DN</unit>
                </Field_Character>

                <Field_Character>
                    <name>Point 4 Value</name>
                    <field_number>5</field_number>
                    <field_location unit="byte">65</field_location>
                    <data_type>ASCII_Integer</data_type>
                    <field_length unit="byte">4</field_length>
                    <field_format>%4d</field_format>
                    <unit>DN</unit>
                </Field_Character>
            </Record_Character>
        </Table_Character>

    </File_Area_Observational>
</Product_Observational>