gis_crash_course

GIS crash course

GIS is everywhere!

  • 80% of all data has some spatial component
  • Spatial data is pervasive across several industries .
  • police 911 call locations
  • tracks of hurricanes
  • 3d seismic data
  • oil pipeline tracks across the country
  • shipping tracks of oil containers
  • fastest route from Palm Springs to LAX </td>
  • steaming traffic data from sensors
  • real estate data in sunny Palm Springs (Location! Location! Location!)
  • weather data from NOAA satellites, automated weather stations
  • facility and utility maps of sewers, electricity lines </td> </tr> </table>
  • Data from newer sources of late

    • IP address pings
    • geocoded photos on flickr, facebook, tweets
    • 3D maps of genomes
    • 3D viz of medical imaging
    • Extra terrestrial maps for space travel, orbital maps for space crafts
    • drone mapping data

    How to represent all this data?

    Vector or feature data

    It is quite suprising that so many types of GIS data can be represented using points, lines and polygons plp

    Sometimes when you have 3D data, it is represented using multipatches - consider these as 3D polygons but can also have textures multipatch

    Feature data are suitable for representing spatially discrete phenomena such as locations of street lamps, railway tracks, state boundaries, 3D building footprints etc.

    Raster and imagery data

    To represent continuous phenomena such as images of Earth taken from space, rainfall and temperature distribution throughout the state etc., we need raster datasets. sat image

    Rasters are great for representing elevation data. Each pixel is the elevation of that ground unit from a datum

    Fundamentally, all rasters are a matrix of numbers

    GIS data in ArcGIS

    GIS data accessed as files on disk

    What are some common data formats?

    • shp, coverages
    • csv
    • esri file geodatabases (fgdb)
    • feature datasets
    • feature classes
    • esri raster grid, mosaic dataset
    • kml, geoJSON
    • GeoTIFF, HDF, netCDF
    • gpx </td>
  • ArcGIS Packages
  • layer, map, project, gp, network, address, tile, scene etc
  • maps, scenes </td> </tr> </table> .
  • GIS data accessed via web layers

    GIS data served over HTTP. What are the different types of ArcGIS services?

    • Feature service
    • Map service
    • Geocode service
    • Geoprocessing service
    • Image service
    • Big data catalog service
    • Network service
    • Schematic service
    • Stream service</b> </td>
  • Scene service
  • Vector tile service</i>
  • Data reviewer service
  • Geodata service
  • Mobile service </td> </tr> </table> The API can work with a number of popular web layers (in bold) and is quickly gaining support for other layer types as well.
  • The graphic below shows the different modules in the API. The module names correspond to the layer types they work with

    In [2]:
    from arcgis.gis import *
    gis=GIS()
    gis.map()