Note 2 - Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Total revenue	$ 25,858	$ 32,715	$ 100,160	$ 95,194
Product [Member]
Total revenue	20,223	19,727	83,434	56,976
Operating Segments [Member] | Oil and Gas Markets [Member]
Total revenue	9,174	17,672	59,930	56,239
Operating Segments [Member] | Oil and Gas Markets [Member] | Traditional Exploration Product Revenue [Member]
Total revenue	2,005	3,363	7,239	9,414
Operating Segments [Member] | Oil and Gas Markets [Member] | Wireless Exploration Product Revenue [Member]
Total revenue	1,460	907	36,008	8,077
Operating Segments [Member] | Oil and Gas Markets [Member] | Reservoir Product Revenue [Member]
Total revenue	189	523	303	810
Operating Segments [Member] | Oil and Gas Markets [Member] | Product [Member]
Total revenue	3,654	4,793	43,550	18,301
Operating Segments [Member] | Adjacent Markets [Member]
Total revenue	15,970	14,862	38,020	38,392
Operating Segments [Member] | Adjacent Markets [Member] | Product [Member]
Total revenue	15,929	14,825	37,897	38,282
Operating Segments [Member] | Adjacent Markets [Member] | Industrial Product [Member]
Total revenue	13,026	11,678	28,492	29,250
Operating Segments [Member] | Adjacent Markets [Member] | Imaging Products [Member]
Total revenue	2,903	3,147	9,405	9,032
Operating Segments [Member] | Emerging Markets [Member]
Total revenue	640	109	1,987	393
Operating Segments [Member] | Emerging Markets [Member] | Product [Member]
Total revenue	$ 640	$ 109	$ 1,987	$ 393