Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Total revenues, net	$ 26,235	$ 22,031
Cost of revenues:
Impairment of Consumer Night Vision Business inventory	2,690
Total cost of revenues	22,241	16,907
Gross profit	3,994	5,124
Operating expenses:
Research and development	6,694	5,175
Selling, general and administrative	8,967	8,682
Total operating expenses	15,661	13,857
Loss from operations	(11,667)	(8,733)
Other income (expense):
Change in fair value of common stock warrant liability	2,194	1,089
Interest expense, net	(69)	(363)
Other income , net		12
Total other income	2,125	738
Income (loss) before provision for income taxes	(9,542)	(7,995)
Income tax benefit		212
Net loss	$ (9,542)	$ (7,783)
Loss per share, basic	$ (0.21)	$ (0.23)
Loss per share, diluted	$ (0.21)	$ (0.23)
Weighted average number of shares outstanding:
Basic	44,429,114	33,661,727
Diluted	44,429,114	33,661,727
Product [Member]
Revenues:
Total revenues, net	$ 23,322	$ 18,685
Cost of revenues:
Cost of goods and services sold	17,797	15,195
Contract [Member]
Revenues:
Total revenues, net	2,913	3,346
Cost of revenues:
Cost of goods and services sold	$ 1,754	$ 1,712