Database Reference
In-Depth Information
Generating detailed building footprints
from LiDAR
Frequently,withspatialanalyses,wereceivedatainoneformthatseemsquiteprom-
ising but need it in another more extensive form. LiDAR is an excellent solution for
suchproblems.LiDARdataislaser-scannereitherfromanairborneplatform,suchas
afixed-wingplaneorhelicopter,orfromagroundunit.LiDARdevicestypicallyreturn
acloudofpointsreferencingabsoluteorrelativepositionsinspace.Asarawdataset,
theyareoftennotasusefulastheyareoncetheyhavebeenprocessed.ManyLiDAR
datasetsareclassifiedintolandcovertypes.So,aLiDARdataset,inadditiontohav-
ingdatathatcontains
x
,
y
,and
z
valuesforallthepointssampledacrossaspace,will
often contain LiDAR points that are classified as ground, vegetation, tall vegetation,
buildings, and so on.
As useful as this is, the data is intensive, that is, it has discreet points, rather than
extensive,aspolygonrepresentationsofsuchdatawouldbe.Thisrecipewasdeve-
lopedasasimplemethodtousePostGIStotransformtheintensiveLiDARsamples
of buildings into extensive building footprints.
