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	<id>https://aowis.org/index.php?action=history&amp;feed=atom&amp;title=Measurement%3AElevation</id>
	<title>Measurement:Elevation - Revision history</title>
	<link rel="self" type="application/atom+xml" href="https://aowis.org/index.php?action=history&amp;feed=atom&amp;title=Measurement%3AElevation"/>
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	<updated>2026-06-15T17:56:56Z</updated>
	<subtitle>Revision history for this page on the wiki</subtitle>
	<generator>MediaWiki 1.45.3</generator>
	<entry>
		<id>https://aowis.org/index.php?title=Measurement:Elevation&amp;diff=597&amp;oldid=prev</id>
		<title>Samuel at 19:50, 10 June 2026</title>
		<link rel="alternate" type="text/html" href="https://aowis.org/index.php?title=Measurement:Elevation&amp;diff=597&amp;oldid=prev"/>
		<updated>2026-06-10T19:50:55Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 19:50, 10 June 2026&lt;/td&gt;
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&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&#039;&#039;&#039;elevation&#039;&#039;&#039; is the canonical, machine readable identifier, and the canonical unit is &#039;&#039;&#039;m&#039;&#039;&#039;, as specified at [[Measurement:Unit_Identifiers|Unit Identifiers]].&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
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&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;= Node Elevation Measurement =&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;= Node Elevation Measurement =&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;

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&lt;/table&gt;</summary>
		<author><name>Samuel</name></author>
	</entry>
	<entry>
		<id>https://aowis.org/index.php?title=Measurement:Elevation&amp;diff=565&amp;oldid=prev</id>
		<title>Samuel at 15:37, 10 June 2026</title>
		<link rel="alternate" type="text/html" href="https://aowis.org/index.php?title=Measurement:Elevation&amp;diff=565&amp;oldid=prev"/>
		<updated>2026-06-10T15:37:50Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 15:37, 10 June 2026&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l1&quot;&gt;Line 1:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 1:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;= Node Elevation Measurement =&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;= Node Elevation Measurement =&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
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&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt; | scope=full page&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;}}&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== 1. Context ==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== 1. Context ==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;

&lt;!-- diff cache key mediawiki:diff:1.41:old-564:rev-565:php=table --&gt;
&lt;/table&gt;</summary>
		<author><name>Samuel</name></author>
	</entry>
	<entry>
		<id>https://aowis.org/index.php?title=Measurement:Elevation&amp;diff=564&amp;oldid=prev</id>
		<title>Samuel: Created page with &quot;= Node Elevation Measurement =  == 1. Context ==  In field deployments, it may appear convenient to use smartphone GPS readings to determine the elevation of pipe network nodes.  However, GPS-based altitude measurements are often insufficient for infrastructure-grade water systems due to:  * low vertical accuracy in consumer devices * atmospheric variation * inconsistent reference datums * drift over time  As a result, relying solely on GPS elevation can lead to incorrec...&quot;</title>
		<link rel="alternate" type="text/html" href="https://aowis.org/index.php?title=Measurement:Elevation&amp;diff=564&amp;oldid=prev"/>
		<updated>2026-06-10T15:36:44Z</updated>

		<summary type="html">&lt;p&gt;Created page with &amp;quot;= Node Elevation Measurement =  == 1. Context ==  In field deployments, it may appear convenient to use smartphone GPS readings to determine the elevation of pipe network nodes.  However, GPS-based altitude measurements are often insufficient for infrastructure-grade water systems due to:  * low vertical accuracy in consumer devices * atmospheric variation * inconsistent reference datums * drift over time  As a result, relying solely on GPS elevation can lead to incorrec...&amp;quot;&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;= Node Elevation Measurement =&lt;br /&gt;
&lt;br /&gt;
== 1. Context ==&lt;br /&gt;
&lt;br /&gt;
In field deployments, it may appear convenient to use smartphone GPS readings to determine the elevation of pipe network nodes.&lt;br /&gt;
&lt;br /&gt;
However, GPS-based altitude measurements are often insufficient for infrastructure-grade water systems due to:&lt;br /&gt;
&lt;br /&gt;
* low vertical accuracy in consumer devices&lt;br /&gt;
* atmospheric variation&lt;br /&gt;
* inconsistent reference datums&lt;br /&gt;
* drift over time&lt;br /&gt;
&lt;br /&gt;
As a result, relying solely on GPS elevation can lead to incorrect hydraulic modeling and unsafe system behavior.&lt;br /&gt;
&lt;br /&gt;
== 2. Normative Requirement ==&lt;br /&gt;
&lt;br /&gt;
All AOWIS-compliant systems:&lt;br /&gt;
&lt;br /&gt;
* MUST NOT use uncalibrated consumer GPS altitude as the sole source of node elevation data for hydraulic or control decisions&lt;br /&gt;
* SHOULD use surveyed or externally validated elevation references where available&lt;br /&gt;
* MAY use GPS-derived elevation only as a temporary or fallback estimate, clearly marked as low-confidence&lt;br /&gt;
&lt;br /&gt;
== 3. Measurement Model ==&lt;br /&gt;
&lt;br /&gt;
Node elevation values MUST be represented as:&lt;br /&gt;
&lt;br /&gt;
* a numeric value relative to a defined vertical datum&lt;br /&gt;
* associated metadata indicating source type&lt;br /&gt;
* optional uncertainty or confidence indicator&lt;br /&gt;
&lt;br /&gt;
== 4. Reference Hierarchy ==&lt;br /&gt;
&lt;br /&gt;
Preferred sources for node elevation:&lt;br /&gt;
&lt;br /&gt;
1. Geodetic survey measurements&lt;br /&gt;
2. Local infrastructure engineering records&lt;br /&gt;
3. Differential GPS or RTK systems&lt;br /&gt;
4. Consumer GPS (fallback only)&lt;br /&gt;
&lt;br /&gt;
== 5. Traceability ==&lt;br /&gt;
&lt;br /&gt;
The restriction on GPS-only elevation sources exists to prevent:&lt;br /&gt;
&lt;br /&gt;
* hydraulic miscalculations&lt;br /&gt;
* incorrect pressure modeling&lt;br /&gt;
* unsafe valve/pump control decisions&lt;/div&gt;</summary>
		<author><name>Samuel</name></author>
	</entry>
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