Teaching With Maps Teaching and learning soil science with maps in the field –began in 2005 Students study maps while in the field and learn how to connect the geomorphic features and soil properties they see on the maps with the real features in the field. –learn how to “read a landscape”
Teaching With Maps Dataset includes all of Indiana –soil properties –topography –land use –bedrock geology –historic maps
On the Web
A Lot of Detail SSURGO Soils Dataset –100+ years of soil survey –originally mapped at 1:20,000 or better –1.3 million polygons, smallest ~2 acres –3.5 to 4.0 million ground truthed observations 2005 Indiana Map Digital Elevation Model –resampled to 5 meter resolution
Large Data Sets, Large Maps Cell Size (meters) PixelsUncompressed Size up to Map Size pixels / in.)* 640 x x KB2 x 4 in 320 x x 1, MB3 x 5 in 160 x 1601,824 x 2,78219 MB7 x 11 in 80 x 803,648 x 5,56477 MB14 x 21 in 40 x 407,298 x 11, MB2 x 4 ft 20 x 2014,591 x 22, GB5 x 7 ft 10 x 1029,181 x 44, GB9 x 14 ft 5 x 5 M58,362 x 89, GB18 x 28 ft * Resolution of Apple iPad (3 rd generation)
The Challenge Move the maps in Isee from ArcGIS running on rugged tablet PCs to an app running on the iPad. –iPad is lighter, longer battery life, no startup time, easier maintenance
Requirements for iPad App Must be able to download the full maps (no need for map server) –grab iPad and take it anywhere GPS input to determine location Easy to zoom and pan
Candidate iPad Apps ArcGIS –requires connection to map server iGIS for iPad –requires maps in Google Maps format thousands of individual files and subdirectories –GPS input MapBox –requires maps in MBTiles format –no GPS input at this time
TileMill Open source map creation program –Mac, Ubuntu Linux, and Windows –raster data as GeoTIFs in Web Mercator projection Tiles the map to the MBTiles format –each map stored in a SQLite database as a single file –Maps can be hosted online by MapBox on own server using TileStream –Maps can be easily downloaded to the iPad and viewed in MapBox