LOCATION DETERMINATION IN A GPS-DENIED ENVIRONMENT WITH USER ANNOTATION

Systems and methods for determining a geographic location of an environment from an image including an annotation on a mobile device without GPS, with no network access, and with no access to peripheral devices or media is described. Open source data indicative of the earth's surface may be obtained and combined into grids or regions. Elevation data may be used to create skyline models at grid points on the surface. An image of an environment may be obtained from a camera on a mobile device. The user of the mobile device may trace a skyline of the environment depicted in the image. The annotation may be used to create reduced regions for edge detection analysis. The edge detection analysis may detect the skyline. The detected skyline may be compared to the skyline models to determine a most likely location of the user.