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Re: Best Practice for encoding spatial coverage

From: Mcgibbney, Lewis J (398M) <Lewis.J.Mcgibbney@jpl.nasa.gov>
Date: Thu, 18 Jun 2015 03:10:14 +0000
To: Frans Knibbe <frans.knibbe@geodan.nl>
CC: SDW WG Public List <public-sdw-wg@w3.org>
Message-ID: <D1A782C3.13906%lewis.j.mcgibbney@jpl.nasa.gov>
Hi Frans,

I have just had a talk with a web developer on the best way of making the extent of a spatial data set known, in a Linked Data context. It is useful to know the spatial extent of a data set because that way a map can be zoomed in on the right patch of Earth.

I would like to throw in an example of some data and metadata used to described it which I use on a day-to-day basis.
The data is from Landsat 7s Enhanced Thematic Mapper (ETM+) instrument and is in HDF4-EOS manifestation with the XML metadata looking like the paste of XML at the end of this message.
You will see the <bounding_coordinates> node but will also note that image corner locations are defined within the <corner> nodes with referenced locations being provisioned for UL (upper left) and LR (lower right) respectively.
Im enjoying seeing the wealth of vocabulary choices being provided by the group, so I wanted to make sure that my use case is also considered.

<?xml version="1.0" encoding="UTF-8"?>

<espa_metadata version="1.1"
xsi:schemaLocation="http://espa.cr.usgs.gov/v1.1 http://espa.cr.usgs.gov/schema/espa_internal_metadata_v1_1.xsd">

        <solar_angles zenith="27.388939" azimuth="136.141678" units="degrees"/>
        <wrs system="2" path="43" row="33"/>
        <corner location="UL" latitude="39.878930" longitude="-121.497290"/>
        <corner location="LR" latitude="37.918700" longitude="-118.804970"/>
        <projection_information projection="UTM" datum="WGS84" units="meters">
            <corner_point location="UL" x="628500.000000" y="4415400.000000"/>
            <corner_point location="LR" x="868800.000000" y="4205100.000000"/>

        <band product="sr_refl" source="toa_refl" name="sr_band1" category="image" data_type="INT16" nlines="7011" nsamps="8011" fill_value="-9999" saturate_value="20000" scale_factor="0.000100" add_offset="0.000000">
            <long_name>band 1 surface reflectance</long_name>
            <pixel_size x="30" y="30" units="meters"/>
            <valid_range min="-2000" max="16000"/>
    <band >
Received on Thursday, 18 June 2015 03:10:48 UTC

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