| WUN Trees, Lights, & Dumpsters This point level
data was collected by resident-student teams. The neighborhood was
divided into 12 sections, with data being collected with an ArcPad
GIS-enabled PDA in six sections and by paper and pencil in the other six
sections.
To facilitate the electronic gathering of this point data, the PDAs
were loaded with three key reference layers: street centerlines, parcel
boundaries, and an aerial photo. GPS was NOT used to identify the
location of trees, lights, or dumpsters. Rather, the data gathering
teams went into the field and made "close enough" approximations of the
location of each element, comparing their actual location in the
neighborhood to the reference maps on the PDA and choosing to place the
point (representing a tree, light, or dumpster) at approximately the right
place.
Data collected by paper followed a similar approach, but points were
marked on a paper map, rather than a digital one in the PDA. After
all the data were gathered, the paper maps were then converted to digital
GIS format utilizing the same ArcPad GIS interface as on the PDAs, but
this time on desktop machines within a computer lab at the University of
Oregon.
This "close enough" method of data collection was used in order to
reduce the technological infrastructure (i.e. differential GPS) needed to
collect data and because the proposed use of the data is for neighborhood
planning activities, not precise engineering solutions, so that broad
patterns were what was of interest. The down side of this data
collection method is that the actual point locations, if superimposed on
an aerial photo, are not always in the correct location. For
example, some street trees points may have coordinates that place them in
a parked car along the street. That said, it's likely that all
points in each file are accurate to within 20 feet of their actual
location.
Parcel-Based Maps
The parcel-based maps are derived from 2002 GIS tax lot data produced
by the Lane Council of Governments. |
