VOLUME 73, NUMBER 7
PHOTOGRAMMETRIC ENGINEERING & REMOTE
SENSING
JOURNAL OF THE AMERICAN SOCIETY FOR PHOTOGRAMMETRY
AND REMOTE SENSING
This month’s front cover shows three samples from a new, nationwide forest type group dataset produced through a collaborative
effort between three USDA Forest Service units – the Remote Sensing Applications Center, Forest Health
Monitoring, and Forest Inventory and Analysis (FIA). These
data use two nested classifi cations (forest types and forest
type groups) to map forest composition, and the data are
available for the contiguous United States and Alaska at
250-meter resolution.
The forest type training data were derived from FIA
plot data. Nearly one hundred geospatially continuous
predictor layers (e.g., MODIS data, DEM derivatives, and
DAYMET climate data) were used as independent variables,
and classifi cation and regression tree (CART) models
were used to produce these datasets. The results are datasets
that show the extent, distribution, and composition
of the nation’s forests. An accuracy assessment using an
independent random holdout was also performed. More
information on the datasets and methodology can be
found in a peer-reviewed article in this month’s PE&RS.
As with any geospatial data, care should be taken
when using moderate resolution data in analyses. These
data should only be used with data of similar scale and
resolution and at 250-m are appropriate for regional to
national scale analyses.
Building boundaries can be determined to a precision of 18 to
21 percent of the lidar point spacing by the proposed tracing
and regularization approach.
Accurate land-cover maps were produced using inter-annual,
multi-temporal Landsat TM/EMT+ imagery and pixel-based
kNN and CART®; segmentation proved unnecessary.