Analyse de l'application Wayback Maps USA pour le 25 janvier

Wayback Maps USA displays U.S. Geological Survey (USGS) maps, from the current USGS Topo national map all the way back to historical topographic maps from previous centuries. • Up to date background map layers, street and imagery • Historic map overlays at many scales and dates • Displays map legend, or "collar" • Turn off collar to align adjacent historic maps • Turn on GPS to find historic maps at your current location • Set marker for measuring position, heading, and distance • Cache maps for offline field use • Comprehensive search of place names • Single purchase for iPhone, iPad, Mac, and Apple Watch TIPS & TRICKS The arrow cursor at the center of the screen points to an exact location on the map. Drag the map to move the cursor's location. Pinch to zoom the map in and out. Press the location icon at bottom left of screen to turn on GPS and move the cursor to your current location on the map. The map rotates in the direction facing the top of your device. Press the location icon again to rotate the map to face north. Turn off location by dragging the map off center. Press the "..." icon at bottom right of screen to display the options menu. Press the "Overlay map" drop down control. Choose an historic map available at the current map location. Maps are listed by year and map scale. The expand button at the upper left will change the drop down to an inline list for closer study. Also on the options menu, press "Search" and type "Fort Point Ca..." The first overlay map listed for this location is "1995 1:24K San Francisco North CA." This is a 7.5 x 7.5 degree minute topographic map of the Golden Gate Bridge area. USGS stopped making this style of hand-drawn map in the 1990s, as it had grown too expensive to keep up to date. The modern replacement map is the computer generated base map displayed in Wayback Maps, USGS Topo. The oldest map in the list is from 1895, 1:62.5K scale. Note the old railway lines that have since vanished. And, of course, there is no Golden Gate Bridge. The overlay map appears with its "collar," the white area surrounding the map that contains the map legend. The "Map collar" toggle controls the display of the collar. With the collar off you can select adjacent maps of the same scale to achieve a seamless view at the map edges. The base map is the background map over which the overlay maps appear. The default base map is "USGS Topo," which is the modern topographic map from USGS. "USGS Imagery" is a similar map but with aerial imagery. Maps downloaded by Wayback are stored in an internal cache. If the cache size is set sufficiently large then you can view your previously viewed Wayback maps without a network connection in the backcountry. To make sure all desired content is cached it is a good idea to preview maps in airplane mode before heading out. To measure distances on the map, move the center arrow cursor to the starting point. Tap the center arrow. A cross mark appears, and the latitude and longitude of this point is displayed. Now move the cursor to the second spot. The arrow points back towards the cross mark and shows the distance. To turn off measurement, tap on the center arrow again. Thank you for using Wayback Maps USA.