EPSG:1069

Change of Vertical Unit

Attributes

Data source: OGP

Information source: EPSG Guidance Note #7-2.

Revision date: 2018-01-19

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Definition: OGP XML

<div class="syntax"><pre><span class="cp">&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot;?&gt;</span> <span class="nt">&lt;gml:OperationMethod</span> <span class="na">xmlns:epsg=</span><span class="s">&quot;urn:x-ogp:spec:schema-xsd:EPSG:1.0:dataset&quot;</span> <span class="na">xmlns:gml=</span><span class="s">&quot;http://www.opengis.net/gml/3.2&quot;</span> <span class="na">xmlns:xlink=</span><span class="s">&quot;http://www.w3.org/1999/xlink&quot;</span> <span class="na">gml:id=</span><span class="s">&quot;iogp-method-1069&quot;</span><span class="nt">&gt;</span> <span class="nt">&lt;gml:metaDataProperty&gt;</span> <span class="nt">&lt;epsg:CommonMetaData&gt;</span> <span class="nt">&lt;epsg:informationSource&gt;</span>EPSG Guidance Note #7-2.<span class="nt">&lt;/epsg:informationSource&gt;</span> <span class="nt">&lt;epsg:revisionDate&gt;</span>2018-01-19<span class="nt">&lt;/epsg:revisionDate&gt;</span> <span class="nt">&lt;epsg:changes&gt;</span> <span class="nt">&lt;epsg:changeID</span> <span class="na">xlink:href=</span><span class="s">&quot;urn:ogc:def:change-request:EPSG::2014.027&quot;</span> <span class="nt">/&gt;</span> <span class="nt">&lt;epsg:changeID</span> <span class="na">xlink:href=</span><span class="s">&quot;urn:ogc:def:change-request:EPSG::2018.004&quot;</span> <span class="nt">/&gt;</span> <span class="nt">&lt;/epsg:changes&gt;</span> <span class="nt">&lt;epsg:show&gt;</span>true<span class="nt">&lt;/epsg:show&gt;</span> <span class="nt">&lt;epsg:isDeprecated&gt;</span>false<span class="nt">&lt;/epsg:isDeprecated&gt;</span> <span class="nt">&lt;/epsg:CommonMetaData&gt;</span> <span class="nt">&lt;/gml:metaDataProperty&gt;</span> <span class="nt">&lt;gml:metaDataProperty&gt;</span> <span class="nt">&lt;epsg:CoordinateOperationMethodMetaData&gt;</span> <span class="nt">&lt;epsg:isOperationReversible&gt;</span>true<span class="nt">&lt;/epsg:isOperationReversible&gt;</span> <span class="nt">&lt;epsg:signReversal</span> <span class="na">changeSign=</span><span class="s">&quot;false&quot;</span> <span class="na">xlink:href=</span><span class="s">&quot;urn:ogc:def:parameter:EPSG::1051&quot;</span> <span class="nt">/&gt;</span> <span class="nt">&lt;epsg:example&gt;</span>Conversion of a height of 25 metres into US survey feet: For the metre (EPSG UoM code 9001) factor b = 1 and factor c = 1, so U1 has a value of 1. For the US survey foot (EPSG UoM code 9003) factor b = 12 and factor c = 39.37, so U2 has a value of approximately 0.304800609601219 (one US survey foot ≈ 0.304800609601219 metres). Then H(ftUS) = (25 * (1 / 1)) / (12 / 39.37) = 82.02 ftUS. For the reverse conversion of 82.02 ftUS into metres: U1 and U2 are as for the forward case, with values of 1/1 and 12/39.37 respectively. Then Hm = (82.02 * (12 / 39.37) / (1 / 1)) = 82.02 m.<span class="nt">&lt;/epsg:example&gt;</span> <span class="nt">&lt;/epsg:CoordinateOperationMethodMetaData&gt;</span> <span class="nt">&lt;/gml:metaDataProperty&gt;</span> <span class="nt">&lt;gml:identifier</span> <span class="na">codeSpace=</span><span class="s">&quot;IOGP&quot;</span><span class="nt">&gt;</span>urn:ogc:def:method:EPSG::1069<span class="nt">&lt;/gml:identifier&gt;</span> <span class="nt">&lt;gml:name&gt;</span>Change of Vertical Unit<span class="nt">&lt;/gml:name&gt;</span> <span class="nt">&lt;gml:formula&gt;</span>Note: These formulas have been transcribed from EPSG Guidance Note #7-2. Users are encouraged to use that document rather than the text which follows as reference because limitations in the transcription will be avoided. If there is a requirement to change the linear unit of a vertical axis, the following formulae can be used: for the forward transformation: X2 = (X1 * U1) / U2 for the reverse transformation: X1 = (X2 * U2) / U1 where U1 and U2 are unit conversion ratios for CRS1 and CRS2 respectively. U = [(factor b) / (factor c)] from the EPSG Dataset Unit of Measure table, populated with respect to the SI base unit, for linear units the metre. Then for the forward transformation: X2 = (X1 * (b1 / c1)) / (b2 / c2) = (X1 * b1 * c2) / (b2 * c1) for the reverse transformation: X1 = [X2 * (b2 / c2)]/ (b1 / c1) = (X2 * b2 * c1) / (b1 * c2)<span class="nt">&lt;/gml:formula&gt;</span> <span class="nt">&lt;gml:generalOperationParameter</span> <span class="na">xlink:href=</span><span class="s">&quot;urn:ogc:def:parameter:EPSG::1051&quot;</span> <span class="nt">/&gt;</span> <span class="nt">&lt;/gml:OperationMethod&gt;</span> </pre></div>
<?xml version="1.0" encoding="UTF-8"?>
 <gml:OperationMethod xmlns:epsg="urn:x-ogp:spec:schema-xsd:EPSG:1.0:dataset" xmlns:gml="http://www.opengis.net/gml/3.2" xmlns:xlink="http://www.w3.org/1999/xlink" gml:id="iogp-method-1069">
  <gml:metaDataProperty>
    <epsg:CommonMetaData>
      <epsg:informationSource>EPSG Guidance Note #7-2.</epsg:informationSource>
      <epsg:revisionDate>2018-01-19</epsg:revisionDate>
      <epsg:changes>
        <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2014.027" />
        <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2018.004" />
      </epsg:changes>
      <epsg:show>true</epsg:show>
      <epsg:isDeprecated>false</epsg:isDeprecated>
    </epsg:CommonMetaData>
  </gml:metaDataProperty>
  <gml:metaDataProperty>
    <epsg:CoordinateOperationMethodMetaData>
      <epsg:isOperationReversible>true</epsg:isOperationReversible>
      <epsg:signReversal changeSign="false" xlink:href="urn:ogc:def:parameter:EPSG::1051" />
      <epsg:example>Conversion of a height of 25 metres into US survey feet:

For the metre (EPSG UoM code 9001) factor b = 1 and factor c = 1, so U1 has a value of 1.

For the US survey foot (EPSG UoM code 9003) factor b = 12 and factor c = 39.37, so U2 has a value of approximately 0.304800609601219 (one US survey foot ≈ 0.304800609601219 metres).

Then H(ftUS) = (25 * (1 / 1)) / (12 / 39.37) = 82.02 ftUS.

For the reverse conversion of 82.02 ftUS into metres:
U1 and U2 are as for the forward case, with values of 1/1 and 12/39.37 respectively.

Then Hm = (82.02 * (12 / 39.37) / (1 / 1)) = 82.02 m.</epsg:example>
    </epsg:CoordinateOperationMethodMetaData>
  </gml:metaDataProperty>
  <gml:identifier codeSpace="IOGP">urn:ogc:def:method:EPSG::1069</gml:identifier>
  <gml:name>Change of Vertical Unit</gml:name>
  <gml:formula>Note: These formulas have been transcribed from EPSG Guidance Note #7-2. Users are encouraged to use that document rather than the text which follows as reference because limitations in the transcription will be avoided.

If there is a requirement to change the linear unit of a vertical axis, the following formulae can be used:

for the forward transformation:       	X2 = (X1 * U1) / U2
for the reverse transformation:        	X1 = (X2 * U2) / U1

where U1 and U2 are unit conversion ratios for CRS1 and CRS2 respectively. U = [(factor b) / (factor c)] from the EPSG Dataset Unit of Measure table, populated with respect to the SI base unit, for linear units the metre.

Then
for the forward transformation:       	
X2 = (X1 * (b1 / c1)) / (b2 / c2) = (X1 * b1 * c2) / (b2 * c1)
for the reverse transformation:        	
X1 = [X2 * (b2 / c2)]/ (b1 / c1) = (X2 * b2 * c1) / (b1 * c2)</gml:formula>
  <gml:generalOperationParameter xlink:href="urn:ogc:def:parameter:EPSG::1051" />
</gml:OperationMethod>