Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 30, 2012	Apr. 30, 2011
Cash flows from operating activities:
Net income	$ 8,456	$ 6,093
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	8,757	6,429
Stock-based compensation	194	216
Provision for inventory obsolescence	60	31
Gross profit from sale of lease pool equipment	(928)	(238)
Excess tax benefit from exercise of non-qualified stock options and restricted shares	(350)
Deferred tax provision	(1,257)	1,195
Changes in non-current income taxes payable		170
Changes in working capital items, net of effects from business combination:
Accounts receivable	4,357	(4,570)
Contracts receivable	(632)	888
Inventories	165	(329)
Prepaid expenses and other current assets	(422)	(193)
Income taxes receivable and payable	532	(334)
Prepaid foreign income tax	(236)
Accounts payable, accrued expenses, other current liabilities and deferred revenue	(832)	1,231
Net cash provided by operating activities	17,864	10,589
Cash flows from investing activities:
Purchases of seismic equipment held for lease	(23,812)	(8,132)
Purchases of property and equipment	(146)	(54)
Sale of used lease pool equipment	2,332	335
Payment for earn-out provision		(155)
Net cash used in investing activities	(21,626)	(8,006)
Cash flows from financing activities:
Net proceeds (payments) on line of credit	6,650	(1,900)
Payments on borrowings	(1,465)	(1,327)
Net proceeds from (purchases of) short-term investments		(101)
Proceeds from issuance of common stock upon exercise of options	96	343
Excess tax benefit from exercise of non-qualified stock options and restricted shares	350
Net cash provided by (used in) financing activities	5,631	(2,985)
Effect of changes in foreign exchange rates on cash and cash equivalents	276	396
Net change in cash and cash equivalents	2,145	(6)
Cash and cash equivalents, beginning of period	15,287	14,647
Cash and cash equivalents, end of period	17,432	14,641
Supplemental cash flow information:
Interest paid	167	306
Income taxes paid	3,821	1,313
Purchases of seismic equipment held for lease in accounts payable at end of period	$ 2,000	$ 19,515