To read a namespace node you have to use the children method.
<?php
$xml = <<<XML
<?xml version="1.0" encoding="UTF-8"?>
<people xmlns:p="http://example.org/ns" xmlns:t="http://example.org/test">
<p:person id="1">John Doe</p:person>
<p:person id="2">Susie Q. Public</p:person>
</people>
XML;
$sxe = new SimpleXMLElement($xml);
$ns = $sxe->getNamespaces(true);
$child = $sxe->children($ns['p']);
foreach ($child->person as $out_ns)
{
echo $out_ns;
}
?>