Field GIS

Summer 2009

Preparing for field expedition

• dowloading basemap layers

  • dems

  • digital orthoquads

  • airphotos

  • other layers: hydrology, roads, etc

• converting basemap layers (illustration)

  • zip

  • tar

  • e00

  • SDTS

  • other formats: mr sid, jpeg, imagine, tiff (world files)

• Representing things (example)

  • Points, Lines, Polygons, Raster, Tin, Attributes (like spreadsheets!)

• Projections and coordinate reference systems (reference ellipsoid) (Dana's overview)

  • Lat, Long, UTM, State Plane

  • Geoid

  • NAD 27/NAD83 (North American Datum)

    • badly registered example

• MetaData - Don't leave the ftp site without it!

  • sleuthing for metadata

• Build your database

  • Choose fields

  • define data types

  • data validation

• Extending the GIS

  • Limitations of commercial GIS

  • GIS as a platform for modelling and analysis (vs programming from scratch...)

  • Where to look for extensions

  • Simple programming structures to "roll your own" algorithm