NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - GENERAL (Details) - USD ($)	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Revenue Recognition
Percentage of unbilled costs and fees expected to be billed and collected during fiscal 2017	98.00%
Retainages	$ 76,000	$ 40,000
Commercial contract retentions and government contract withholdings as a percent of fees	15.00%
Warranty Costs
Parts and labor warranty period for certain of the company's products with purchase of domestic equipment	1 year
Parts only or parts and labor warranty period for certain of the products with purchase of international equipment	1 year
Deferred Revenue
Minimum period covered under extended warranty and service contracts	1 year
Maximum period covered under extended warranty and service contracts	5 years
Impairment of Long-Lived Assets
Impairment costs	$ 0	0	$ 0
Accrued Salaries and Benefits
Accrued payroll and payroll related taxes	889,000	1,145,000
Accrued incentive compensation	1,859,000	3,849,000
Accrued vacation	1,496,000	1,775,000
Accrued severance	321,000
Total accrued salaries and benefits	4,565,000	6,769,000
Other Current Liabilities
Other accrued expenses	2,075,000	3,277,000
Accrued contract related costs	156,000	1,736,000
Accrued professional fees	753,000	433,000
Accrued sales commissions	219,000	290,000
Total other current liabilities	3,203,000	5,736,000
Research and Development
Research and development expenses	21,722,000	23,390,000	22,089,000
Revenue recognized related to government and customer-sponsored research and development	$ 986,000	$ 918,000	$ 698,000
Income per Common and Potential Common Shares
Common stock equivalents excluded from diluted earnings per share as their effect is anti-dilutive (in shares)	218,000	211,000	176,000
Earnings per Share - Basic:
Net (loss) income	$ (3,249,000)	$ 979,000	$ 15,117,000
Less: Distributed and undistributed earnings (losses) to unvested restricted stock units	30,000	2,000	(44,000)
Distributed and undistributed earnings to common shareholders - Basic	$ (3,219,000)	$ 981,000	$ 15,073,000
Weighted average number of common shares outstanding - basic (in shares)	7,161,000	7,723,000	7,846,000
(Loss) income per share - basic (in dollars per share)	$ (0.45)	$ 0.13	$ 1.92
Earnings per Share - Diluted:
Weighted average number of common shares outstanding - basic (in shares)	7,161,000	7,723,000	7,846,000
Dilutive effect of stock-based awards (in shares)		6,000	35,000
Weighted average number of common and potential common shares outstanding - diluted (in shares)	7,161,000	7,729,000	7,881,000
(Loss) income per share - diluted (in dollars per share)	$ (0.45)	$ 0.13	$ 1.91
Minimum
Revenue Recognition
Period of certain long-term, custom-built systems or contract engineering projects	1 year
Maximum
Revenue Recognition
Period of certain long-term, custom-built systems or contract engineering projects	5 years