Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues:
Total revenues, net	$ 5,361	$ 7,066	$ 11,473	$ 13,933
Cost of revenues:
Impairment of Consumer Night Vision inventory		2,690		2,690
Total cost of revenues	5,136	6,960	9,912	11,847
Gross profit	225	106	1,561	2,086
Operating expenses:
Research and development	1,300	1,720	2,897	3,351
Selling, general and administrative	1,777	2,031	3,716	4,943
Total operating expenses	3,077	3,751	6,613	8,294
Loss from operations	(2,852)	(3,645)	(5,052)	(6,208)
Other income (expense):
Change in fair value of common stock warrant liability	536	(1,427)	1,330	(924)
Interest expense, net	(21)	(30)	(55)	(72)
Other income , net		37		58
Total other income	515	(1,420)	1,275	(938)
Loss before provision for income taxes	(2,337)	(5,065)	(3,777)	(7,146)
(Provision) benefit for income taxes
Net loss	(2,337)	(5,065)	(3,777)	(7,146)
Less net income allocated to participating securities
Net loss allocated to common shares	$ (2,337)	$ (5,065)	$ (3,777)	$ (7,146)
Loss per share, basic and diluted	$ (0.05)	$ (0.11)	$ (0.08)	$ (0.16)
Weighted average number of shares outstanding:
Basic and Diluted	48,817,940	45,111,273	46,979,505	43,691,117
Product [Member]
Revenues:
Total revenues, net	$ 4,958	$ 6,216	$ 10,465	$ 12,079
Cost of revenues:
Cost of goods and services sold	4,898	3,971	9,324	8,330
Contract [Member]
Revenues:
Total revenues, net	403	850	1,008	1,854
Cost of revenues:
Cost of goods and services sold	$ 238	$ 299	$ 588	$ 827