The U.S. Geological Survey Astrogeology Program takes another step forward in
reviving the lunar data from the 1960’s. The cartographic group is evaluating
the use of modern softcopy digital mapping techniques to extract a digital
elevation model (DEM) from Lunar Orbiter (LO) and Apollo digitized imagery.
Products enabled by this endeavor will supersede earlier maps and will be
functional for upcoming lunar missions and coincide with the vision to gain a
new foothold on the moon.
The original Lunar Orbiter photographs reconstructed in the 1960’s had limited
utility for topographic mapping due to stair-step artifacts in the reconstructed
photographs. To correct this problem, Lunar Orbiter images were digitized and
reconstructed to fit tto calibrated
reseaux
and
fiducials
locations, and the stair-step artifacts in the resulting images were greatly
reduced.
Although the Apollo imagery was previously used to produce topographic maps,
they were limited in size and accuracy, and most notably, had kilometer-sized
offsets between them because different control networks were employed during
their production.
To correct this, a revised global network for the Moon that included Clementine
imagery acquired in the 1990’s was generated, so that future mapping would be
based on a common control network.
The Unified Lunar Control Network 2005 improved the accuracy and the density of
control points and included computed elevations values for each point.
To take reviving Lunar Orbiter to
another level, the cartographic group considers the pros and cons for using
digital elevation models from Apollo (metric vs. panoramic) and/or Lunar Orbiter
imagery to produce controlled DEMs, orthoimage mosaics and other products that
will be useful in future mission planning and scientific analysis. Upcoming
missions such as SELENE – Japan, Chang’e 1 –China, Chandrayaan-1 – India, and -Lunar
Reconnaissance Orbiter - USA, will have access to highly detailed topographic
data.
President Bush announced in a press
release, on January 14, 2004, that our goal is to return to the moon by 2020.
"Beginning no later than 2008, we will send a series of robotic missions to the
lunar surface to research and prepare for future human exploration." The
Astrogeology team continues their lunar groundwork.
Learn more about Lunar
Orbiter, ULCN
2005 network, and Mapping
with Apollo Images
Posted by HotTopicsJournalist
in Astrogeology
at
14:59