VOLUME 72, NUMBER 10
PHOTOGRAMMETRIC ENGINEERING & REMOTE
SENSING
JOURNAL OF THE AMERICAN SOCIETY FOR PHOTOGRAMMETRY
AND REMOTE SENSING
Global mosaics of the clearest Landsat-7 acquisitions for 2000 (top),
2001 (middle), and 2002 (bottom), compiled from GloVis browse images (http://glovis.usgs.gov/). Cloud
defi nition is calculated using ACCA (Irish et al.); acquisitions are determined using LTAP (Arvidson et al.).
Compared to the historical archive (Goward et al., Green), Landsat 7 has produced the most comprehensive
global coverage—for the seven continents
as well as Oceania—ever achieved (Williams et al.).
The global coverage in the mosaics is consistent, with
a few exceptions: year 2000 coverage of Antarctica
was wall-to-wall versus the later years that focused
on active coastal ice sheets and cloud-prone regions;
acquisitions over the central Atlantic in 2002 were
collected for calibration activities at USGS/EROS
and NASA/GSFC. The darker green, red, and blue
tonal variations represent scenes where cloud contamination
and/or snow are present. Green is healthy
vegetation. Red is bare soil and dead vegetation.
Blue is snow and ice. Individual scene enhancement
during browse image generation causes the contrast.
These highlight the locations—humid tropics, Boreal
regions—where Landsat-7 16-day repeat coverage
is not frequent enough to produce consistent clear
views (Irons and Masek). These mosaics may be
inspected in detail at http://landsat.usgs.gov/gallery/
L7WorldMosaics/ . (Images courtesy of the U.S.
Geological Survey.)
Peer-Reviewed Articles (Click the linked titles to see the
full abstract) (Important Note: abstracts are displayed here in the order they were intended to appear in the printed journal. The ordering error was discovered post printing)
The Landsat-7 system in context and showing how mission
operations have changed over time, increasingly exploiting
the global monitoring capabilities of the Landsat observatory.
A comprehensive review of the U.S. Landsat archive holdings
has revealed signifi cant gaps in the archive of Landsat acquisitions
from the last 34+ years. Analyses are underway to
identify the reasons for these gaps and, where possible, identify
holdings at the International Cooperator ground stations
that may assist in fi lling the gaps in the U.S. archive.
Summary of the validation of the Landsat-7 Long-Term
Acquisition Plan, an approach for assuring acquisition of a
seasonally-refreshed, essentially cloud-free global archive of
Landsat-7 data.
The history, rationale, and results of the strategies employed
to set the radiometric gains for the ETM+ instrument as part
of the Landsat-7 Long-Term Acquisition Plan (LTAP).