@book{24864,
	author = {Butler, James, ed.},
	title = {Earth Observing Systems XX},
	publisher = {SPIE},
	year = {2015},
	series = {Proceedings of SPIE; V. 9607},
	address = {Washington, USA},
	url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/9607}
}