Note 2 - Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Total revenue	$ 32,715	$ 20,691	$ 95,194	$ 63,382
Product [Member]
Total revenue	19,727	13,463	56,976	48,060
Operating Segments [Member] | Oil and Gas Markets [Member]
Total revenue	17,672	9,517	56,239	34,317
Operating Segments [Member] | Oil and Gas Markets [Member] | Traditional Exploration Product Revenue [Member]
Total revenue	3,363	1,592	9,414	3,389
Operating Segments [Member] | Oil and Gas Markets [Member] | Wireless Exploration Product Revenue [Member]
Total revenue	907	100	8,077	14,358
Operating Segments [Member] | Oil and Gas Markets [Member] | Reservoir Product Revenue [Member]
Total revenue	523	692	810	1,513
Operating Segments [Member] | Oil and Gas Markets [Member] | Product [Member]
Total revenue	4,793	2,384	18,301	19,260
Operating Segments [Member] | Adjacent Markets [Member]
Total revenue	14,862	10,938	38,392	28,312
Operating Segments [Member] | Adjacent Markets [Member] | Product [Member]
Total revenue	14,825	10,894	38,282	28,179
Operating Segments [Member] | Adjacent Markets [Member] | Industrial Product [Member]
Total revenue	11,678	7,465	29,250	18,471
Operating Segments [Member] | Adjacent Markets [Member] | Imaging Products [Member]
Total revenue	3,147	3,429	9,032	9,708
Operating Segments [Member] | Emerging Markets [Member]
Total revenue	109	135	393	571
Operating Segments [Member] | Emerging Markets [Member] | Product [Member]
Total revenue	109	135	393	571
Operating Segments [Member] | Corporate Segment [Member]
Total revenue	$ 0	$ 50	$ 0	$ 50