Restricted cash (Tables)

12 Months Ended

Dec. 31, 2012

Restricted Cash Tables

Letters of credit

These letters of credit include contractual performance bonds related to conducting certain SFD® surveys.

	2012			2011
Total restricted cash	$	433,369		$	74,135
Less current portion, amounts scheduled to be released to NXT within 12 months		(433,369	)		-
	$	-		$	74,135