Note 2 - Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Total revenue	$ 124,509	$ 89,253
Product [Member]
Total revenue	73,333	64,109
Operating Segments [Member] | Oil and Gas Markets [Member]
Total revenue	73,993	49,141
Operating Segments [Member] | Oil and Gas Markets [Member] | Traditional Exploration Product Revenue [Member]
Total revenue	12,081	6,558
Operating Segments [Member] | Oil and Gas Markets [Member] | Wireless Exploration Product Revenue [Member]
Total revenue	10,168	15,822
Operating Segments [Member] | Oil and Gas Markets [Member] | Reservoir Product Revenue [Member]
Total revenue	962	1,968
Operating Segments [Member] | Oil and Gas Markets [Member] | Product [Member]
Total revenue	23,211	24,348
Operating Segments [Member] | Adjacent Markets [Member]
Total revenue	49,039	39,171
Operating Segments [Member] | Adjacent Markets [Member] | Product [Member]
Total revenue	48,888	39,000
Operating Segments [Member] | Adjacent Markets [Member] | Industrial Product [Member]
Total revenue	36,859	25,640
Operating Segments [Member] | Adjacent Markets [Member] | Imaging Products [Member]
Total revenue	12,029	13,360
Operating Segments [Member] | Emerging Markets [Member]
Total revenue	1,234	711
Operating Segments [Member] | Emerging Markets [Member] | Product [Member]
Total revenue	1,234	711
Operating Segments [Member] | Corporate Segment [Member]
Total revenue	$ 0	$ 50