Note 1 - Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2023	Sep. 30, 2022
Restricted Cash	$ 200	$ 200
Credit Terms for Trade Receivables (Day)	30 days
Extended Credit Terms for Trade Receivables (Day)	60 days
Revenues	$ 124,509	89,253
Emerging Markets [Member]
Impairment, Long-Lived Asset, Held-for-Use	0
Geospace Technologies Eurasia LLC [Member]
Net Carrying Value of Subsidiary	5,800
Imported Product for Resale	3,800
Geospace Technologies Eurasia LLC [Member] \| Geographic Distribution, Domestic [Member]
Revenues	1,800
Customer One [Member]
Accounts and Financing Receivable, after Allowance for Credit Loss	3,500	$ 5,500
Customer Two [Member]
Accounts and Financing Receivable, after Allowance for Credit Loss	$ 4,800
Revenue Benchmark [Member] \| Customer Concentration Risk [Member] \| Customer One [Member]
Concentration Risk, Percentage	26.70%	29.30%
Revenue Benchmark [Member] \| Customer Concentration Risk [Member] \| Customer Two [Member]
Concentration Risk, Percentage	11.70%
Revenue Benchmark [Member] \| Product Concentration Risk [Member] \| Certain Models of Oil and Gas Marine Wireless Products [Member]
Concentration Risk, Percentage	4.00%	11.00%
Revenue Benchmark [Member] \| Product Concentration Risk [Member] \| Thermal Film [Member]
Concentration Risk, Percentage	5.00%	8.00%
Minimum [Member]
Cash, Uninsured Amount	$ 5,000
Subsidiaries [Member] \| Non-US [Member]
Cash Equivalents, at Carrying Value	3,800
Subsidiaries [Member] \| RUSSIAN FEDERATION
Cash Equivalents, at Carrying Value	$ 2,500

Credit terms for trade receivables.

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Amount of imported product for resale during the period.

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Amount of short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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The aggregate amount of write-downs for impairments recognized during the period for long lived assets held for use (including those held for disposal by means other than sale).

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Amount of cash restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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