All GIS layers are in Shapefile format (GIS software required).

	GIS LAYER FROM FIGURE 1.4
	Sheet layout of the International Map of the World – 4° × 6° grid, with sheet numbers
	William Rankin Creative Commons BY-NC-SA
	GIS LAYER SIMILAR TO FIGURE 3.13
	Zones of the US State Plane Coordinate System
	data from ESRI
	GIS LAYERS FROM FIGURES 4.1 AND 4.11
	Grid lines of the Universal Transverse Mercator system – grid zones and 100-km grid, with Military Grid Reference System info
	data from the US National Geospatial-Intelligence Agency
	GIS LAYERS FROM FIGURE 5.11
	Loran during World War II – transmitter locations and chain connections (see image for coverage extent)
	data from J. A. Pierce, A. A. McKenzie, and R. H. Woodward, eds., Loran: Long Range Navigation (New York: McGraw Hill, 1948), appendix B
	GIS LAYERS FROM FIGURE 5.24
	Loran-A after World War II – transmitter locations and chain connections (see image for coverage extent)
	data from loran-history.info and “Loran-A is Alive and Well... and Living in China,” Wild Goose Association Radionavigation Journal (1985–1986): 47
	GIS LAYERS FROM FIGURE 5.25
	Loran-C – transmitter locations and chain connections (see image for coverage extent)
	data from loran-history.info, Wikipedia (including Soviet Chayka), and “Suez Canal Loran-C Installed,” Wild Goose Association Newsletter (Summer 1982): 5−6
	GIS LAYERS FROM FIGURE 5.23
	Decca Navigator – transmitter locations and chain connections (see image for coverage extent and Dectra tracks)
	data from Jerry Proc; for approximate locations of nuclear-test stations in the Pacific, see “Operation Grapple,” Decca Navigator News 21 (Dec 1957): 6–7
	GIS LAYER FROM FIGURE 6.7
	Omega transmitter locations – final stations only
	data from Peter B. Morris et al., Omega Navigation System Course Book, Vol. 1 (Alexandria: US Department of Transportation, 1994), pages 2-11 to 2-21
	GIS LAYERS FROM FIGURE 6.18
	Differential GPS beacons (approximate coverage shown with 200-nm buffers)
	data from Alan Gale's DGPS Beacons of the World (use Ctrl-F to find it on this page)