$re = '/^S0\w*(?:-\d+)?\W* 11\b/m';
$str = 'V0EQ21309-128 1 1001600535.99N0023642.63E 478409.56662024.7 107.91520748348
S0EQ21309-128 11 1001600532.60N0023645.31E 478450.26661919.6 0.01520748348
T0EQ21309-128 1 1 1001600452.10N0023713.63E 478880.66660664.0 0.01520748348
T0EQ21309-128 1 2 1001600452.35N0023715.00E 478901.96660671.8 0.01520748348
C0EQ21309-128 111 1001600532.07N0023645.24E 478449.06661903.2 0.01520748348
C0EQ21309-128 113 1001600532.22N0023646.01E 478461.06661907.6 0.01520748348';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php