New Topographic Map Formats

While looking for a map on the US Geological Survey site today I found a new format of topographic maps. Previously it was easy to download a scanned topographic map in pdf format. Today I noticed that for some regions there is a new kind of map called a US Topo. It has a true color aerial photo for a base with all the usual topographic map features on top.

For example, below is a part of the Iron Springs 7.5 minute map showing the Waynesboro Reservoir, which was made in 1995.

Following is the June 2010 version of the same area.

For some maps there is a Digital Maps beta version that doesn't yet have the contour lines. The new maps can be purchased in paper format. Even better is the pdf format. The data in the new maps can be separated in the reader, just like in a GIS. When you install the free TerraGo add-on in Adobe Reader you can make measurements of direction and distance directly on the map. Very Cool! It is all available at http://store.usgs.gov Topographic maps will never be the same again!

End of Selective Availability Anniversary

The June 2010 issue of  Forestry Source (subscription required) contains a short primer on GPS. Author Steve Wilent mentioned the tenth anniversary of the end of Selective Availability (SA) on May 1, 2000, following an executive order by President Clinton. Under the SA program deliberate error was introduced into the GPS signal so that the live signal would have an error of about 100 meters. This was done to protect national security during military operations. Only military GPS receivers had a chip to remove the error.

The policy was changed to promote the use of GPS in the general economy. The military agreed fully with the new policy. There were ways around SA, by using a supplemental FM correction signal broadcast locally by the US Coast Guard or by doing post-processing correction of field data in the office.

Now that the GPS signals has no more deliberately introduced error the use of GPS has grown dramatically  in all parts of the economy from cars to personal devices. The sport of geocaching would not be possible if SA were still in operation.

For foresters, the end of SA has meant that low cost, rugged, recreational grade GPS receivers can be used for most forestry operations. The accuracy of these receivers is more than enough for most forestry mapping  operations. The forest technology program at Penn State Mont Alto has been able to acquire sufficient receivers so that all the students can have one to use for field work. Collecting GPS data in the field and using it to create maps has now become a normal part of all fieldwork.

We should make the end of SA a national holiday!

Wildfire Maps

This year's fire season began with unusually fierce and intense fires, especially in Northern California. The California Department of Forestry and Fire Protection has put together an interactive Google Map showing the status of active and contained fires and emergency services. The map can be seen here.

The US Forest Service Remote Sensing Application Center has put together a number of maps in its Modis Active Fire Mapping Program. The site includes a number of imaging products including interactive ArcIMS maps and Google Earth downloads. Complete data on the fires is also available.

With more people moving into rural areas, the increase in forest fuels, and the capricious climate the problem of widlfires will be with us for a long time. Fortunately, we have reliable real time sources of information with which to study the fires and come up with solutions.

Mont Alto Hiking Trails

Follow this link, http://tinyurl.com/2j7bto to a map of hiking trails around the Mont Alto Campus made by forest technology student Tom Oliver for the GIS class.

Tom made the map with the new design tools in Google Maps. Very simple to use, all you need to do is navigate to the area you want and use the simple drawing tools. You can then send your map to anyone or even download it to view on Google Earth.

Enjoy!