<?xml version="1.0" encoding="UTF-8"?>
<?xml-model href="https://pds.nasa.gov/pds4/pds/v1/PDS4_PDS_1D00.sch" schematypens="http://purl.oclc.org/dsdl/schematron"?>

<Product_Context xmlns="http://pds.nasa.gov/pds4/pds/v1"
    xmlns:pds ="http://pds.nasa.gov/pds4/pds/v1" 
    xmlns:ctli="http://pds.nasa.gov/pds4/ctli/v1"
    xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation=
    "http://pds.nasa.gov/pds4/pds/v1  https://pds.nasa.gov/pds4/pds/v1/PDS4_PDS_1D00.xsd">
    
    <Identification_Area>
        <logical_identifier>urn:nasa:pds:context:telescope:goldstone.dss12_26m</logical_identifier>
        <version_id>1.0</version_id>
        <title>DSS-12 26-m Radio Telescope</title>
        <information_model_version>1.13.0.0</information_model_version>
        <product_class>Product_Context</product_class>
        <Modification_History>
            <Modification_Detail>
                <modification_date>2020-07-19</modification_date>
                <version_id>1.0</version_id>
                <description>
                    Original context file for the DSS-12 antenna at Goldstone
                    with 26-m aperture (1959-1979).
                </description>
            </Modification_Detail>
        </Modification_History>
    </Identification_Area>
    
    <Reference_List>
        <Internal_Reference>
            <lid_reference>urn:nasa:pds:radiosci.documentation:dsn.810-005</lid_reference>
            <reference_type>instrument_to_document</reference_type>
            <comment>
                This reference is to a PDS collection containing several versions of the NASA Deep 
                Space Network (DSN) Telecommunications Link Design Handbook (Document 810-005).
                The Handbook is maintained in a modular format to provide interface 
                design data to flight projects using the DSN.  Modules are updated as appropriate.
                Each member product in the PDS collection is the set of modules as they applied
                at that point in time.  Modules include:
                001 Handbook Introduction
                101 70-m Subnet Telecommunications Interfaces
                102 26-m Subnet Telecommunications Interfaces (omitted in 2009 and later versions)
                103 34-m HEF Subnet Telecommunications Interfaces
                104 34-m BWG Antennas Telecommunications Interfaces
                105 Atmospheric and Environmental Effects
                106 Solar Corona and Solar Wind Effects
                107 Radio Source Catalog
                201 Frequency and Channel Assignments
                202 34-m and 70-m Doppler
                203 Sequential Ranging
                205 Command Service
                206 Telemetry General Information
                207 34-m and 70-m Telemetry Reception
                208 Telemetry Data Decoding
                209 Open-Loop Radio Science
                210 Delta Differrential One-way Ranging
                211 Wideband Very Long Baseline Interferometry
                214 Pseudonoise and Regenerative Ranging
                301 Coverage and Geometry
                302 Antenna Positioning
                303 Media Calibration
                304 Frequency and Timing
                305 Test Support
                901 Handbook Glossary
            </comment>
        </Internal_Reference>
        
        <Internal_Reference>
            <lid_reference>urn:nasa:pds:context:facility:observatory.dsn</lid_reference>
            <reference_type>telescope_to_facility</reference_type>
            <comment>
                This context product provides more information on the NASA Deep Space Network as a whole.
            </comment>
        </Internal_Reference>
        
        <Internal_Reference>
            <lid_reference>urn:nasa:pds:context:facility:observatory.goldstone</lid_reference>
            <reference_type>telescope_to_facility</reference_type>
            <comment>
                This context product provides more information on the Goldstone Deep Space Communications Complex.
            </comment>
        </Internal_Reference>
        
        <Internal_Reference>
            <lid_reference>urn:nasa:pds:context:telescope:goldstone.dss12_34m</lid_reference>
            <reference_type>context_to_associate</reference_type>
            <comment>
                This context product provides more information on DSS-12 when its
                aperture was 34 meters (1979-2012).
            </comment>
        </Internal_Reference>
        
        <Internal_Reference>
            <lid_reference>urn:nasa:pds:context:instrument:dsn.rss</lid_reference>
            <reference_type>telescope_to_instrument</reference_type>
            <comment>
                This context product provides more information on the commanding, radio tracking, and
                radio science instrumentation at the telescope.  Only information appropriate to years
                1996 and earlier would be applicable to DSS-12 operations.
            </comment>
        </Internal_Reference>
        
        <External_Reference>
            <reference_text>https://www.gdscc.nasa.gov/?page_id=40</reference_text>
            <description>
                An overview of the Goldstone Deep Space Communication Complex with photographs.
            </description>
        </External_Reference>
    </Reference_List>
    
    <Telescope>
        <aperture unit='m'>26</aperture>
        <telescope_longitude unit='deg'>243.203</telescope_longitude>
        <telescope_latitude unit='deg'>35.290</telescope_latitude>
        <coordinate_source>WGS 84 Ellipsoid</coordinate_source>
        <description>
            Echo Station (DSS-12) is currently the administrative center for the Goldstone Deep Space
            Communications Complex (GDSCC).  Built in 1959 with a 26-m aperture, DSS-12 is named for 
            early experiments performed with the passive balloon satellite, Echo 1.  The antenna is 
            polar mounted, was upgraded to a 34-m aperture in 1979, and was capable of simultaneously 
            operating at both S- and X-band frequencies.  For 37 years, DSS-12 supported many spacecraft 
            including the early Ranger and Surveyor missions to the Moon, deep space missions such as 
            Pioneer and Voyager, and high Earth orbiting spacecraft.  Antenna coordinates 
            are approximate; they were interpolated from coordinates for DSS-13 and DSS-14 in Table 5
            of module 301 (revision L) of the DSN Telecommunications Link Design Handbook (DSN document
            810-005) using the map at https://www.gdscc.nasa.gov/?page_id=37
        </description>
    </Telescope>
    
</Product_Context>
