Geographic Data Primitives Large number: Points, multiipoints, lines, polylines, splines, rasters, images, surfaces, networks…. But, 95% of the time we deal with these five: RESIN GIS Workshop #1, November 6, 2009, John Radke, Howard Foster
GIS data primitives, cont. The standard five: Points Lines (aka “arcs”)
Geo-primitives, cont. Polygons Rasters Images (many image formats)
Geo-primitives, the big idea That almost all of these primitives can be linked to attribute information via an unique identfier imbedded within each object. 2102
Attributes of geo-primitves 2102
Levee segment data (many names) example
GIS display controls Render: color, transparency, line style, symbol style, color gradients,… Render simply or by attribute characteristic Attributes can be selected (e.g., “fact” < 3) for further control over data display (ArcMap only) Draw order can be changed, layers turned off and on. Masking, labeling, etc. Backdrop imagery
RESIN GIS data service design Core RDBMS Postgres/ PostGIS File system (shapefiles, jpegs, etc) SQL SQL Metadata Browser Web Browser Web server technologies Google Maps Mapserver Openlayers Calmap ESRI Spatial Data Engine (SDE) Clients Workstation Arcgis Arc Explorer GISC MapView Web browser
GIS data clients Biggest problem Additional issues, workarounds ArcView 3.0 No annotation facilities ArcGIS ArcMap desktop Requires license, dense interface Too complex, difficult to make annotations ArcGIS Explorer .net Can’t display by attribute, ugly geographic projection only Pre-set attribute views can be done with .lyr files. ArcGIS Explorer java No annotations, no ESRI raster data, no transparency Convert rasters to images, jpegs are problematic GISC’s MapView Buggy, requires all data to be in the same projection
ArcGIS Explorer .net Only runs on Windows machines Attempts to out-Google Earth with on-line connection to good backdrop imagery Supports all major ESRI GIS data types, including real-time data (SDE), supports real-time reprojection so you can use data from different sources.
.net Arc Explorer cont. The good: Supports annotations. Backdrop imagery is high quality and fast at the desktop. The bad: Doesn’t (yet?) support display-by-attribute (clumsy work-around exists.) Poor quality with some raster data Does not datum shift (also java version too).
.net Arc Explorer cont. You must use local data (files on disk) when in the field. You must set the display to 2D mode. You must understand the difference between layers and shapefiles and the different ways you access them.
.net Arc Explorer Resources: http://calmap.gisc.berkeley.edu/resin_gis You will see software download directories, help documents, data interfaces, etc.
Demo: Access files from a local directory: C:/temp/resin/data_mix Start up Arc Explorer, switch to 2D mode Pre-defined layer list is infrastructure_setup.nmf