Wednesday, July 2, 2014

USGS Historical Topographic Map Explorer for Search and Rescue

While we always want to use the most up to date maps (a Local GIS-produced basemap, World Topographic, Open Street Map)  for our missing person search operations - there are times when historic maps are necessary for our investigation. For instance what if your missing person was believed to be carrying a historic map - you might want to interpret the landscape through the same map they were using. 

This dynamic map allows you to view and download historic quad maps based on location - this could be a very useful tool for Search and Rescue in the US! 

Check it out: USGS Historical Topographic Map Explorer

1) Type in a place and click on the map
2) Click timeline maps to view in main window

3) Slide transparency on map to compare, or drag/drop to re-order maps

The downloads appear to be available as geo-pdfs only - but these may be converted to more GIS friendly formats (.tif). I look forward to hearing if any teams have used this resource and any feedback they may have. 

If you simply want a seamless USGS Topo - this is already a layer in ArcGIS Online that can be used as a basemap in ArcGIS Desktop or ArcGIS Online while connected to the internet.

View Larger Map

If you are looking for the USGS topographic maps to run locally in ArcMap - most states have a download page for pulling the digital raster graphics (DRGs). I have also heard that Matt Jacobs from CalTopo can show how to use the seamless tiles he has produced inside your GIS. 

However - basemaps should always be suspect to currency and  used in conjunction with your local minimum essential dataset (read Chapter 3).

Thanks USGS for making data open and easier to find!