HR: 10:35h
AN: U32A-02 [Abstracts]
TI: Medium Resolution Global Earth Observations with Landsat: Looking 35 Years Back and 50 Years Forward
AU: * Williams, D L
EM: Darrel.L.Williams@nasa.gov
AF: Earth Sciences Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, United
States
AU: Irons, J R
EM: James.R.Irons@nasa.gov
AF: Earth Sciences Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, United
States
AU: Goward, S N
EM: sgoward@umd.edu
AF: Department of Geography, University of Maryland, College Park, MD 20742, United States
AB:
The modern era of global medium resolution satellite remote sensing was inaugurated 35 years ago, in July
1972, with the launch of the first Landsat satellite carrying the Multispectral Scanner (MSS) sensor. Ten years
after that first launch, Landsat 4 carried a much-improved sensor aloft, the Thematic Mapper. The TM provided
better spatial resolution (30 m versus 79 m) than the MSS, as well as additional spectral bands in the mid-
infrared (IR) and thermal IR regions. Roughly another decade later, in April 1999, the Enhanced Thematic Mapper
Plus (ETM+) instrument was placed in orbit on Landsat 7. The ETM+ provided a new 15 m panchromatic band
and a much-improved thermal band resolution (60 m versus 120 m). Through a combination of planning and
good luck, the various Landsat missions have delivered a continuous set of calibrated, multispectral images of
the Earth's surface spanning this entire 35-year time period. This imagery database has been used in
agricultural evaluations, forest management inventories, geological surveys, water resource estimates, coastal
zone appraisals, and a host of other applications to meet the needs of a very broad user community, including
business, government, science, education, national security, and now -- even the casual observer -- as Landsat
imagery provides the skeletal backbone of Google Earth. Landsat established the U.S. as the world leader in
terrestrial remote sensing, contributed significantly to the understanding of the Earth's environment, spawned
revolutionary uses of space-based data by the commercial value-added industry, and encouraged a new
generation of commercial satellites that provide regional, high-resolution spatial images.
In spite of the overall success of the Landsat series of satellites, the first 35 years of the Landsat legacy have
been extremely challenging as the push to embrace new technologies was often questioned by those who simply
wanted to maintain whatever the current capability was at that point in time. For example, the early days of the TM
provided a data rate and storage volume that most users did not have the capability to handle computationally. In
addition to these technology-based debates, the Landsat program experienced continuous turmoil and
unknowns when it came to the funding and management oversight of each subsequent mission. Following
years of debate, in August 2007, the Office of Science and Technology Policy (OSTP) at the White House issued a
press release announcing the creation of the National Land Imaging Program (NLIP) to ensure the availability of
Landsat class data far into the future. The NLIP is to provide a mechanism within the Interior Department to
assess the land imagery needs of federal, state and local land management officials, scientists, and geographic
researchers, and to translate those needs into the technical capabilities of future satellites. Thus, continuity of
digital image data provided by the Landsat series of satellites looks to be very promising.
As stated in the descriptive paragraph for this session, the need for monitoring the Earth is now more acute than
ever, and the development and implementation of useful long-term global observations, such as the Landsat
series of satellites has provided, is one of the major scientific challenges of our time. We propose to document
the lessons learned from Landsat's global observations in recent decades, and to apply these lessons to
analysis of current and future needs.
DE: 1630 Impacts of global change (1225)
DE: 1632 Land cover change
DE: 1640 Remote sensing (1855)
DE: 1694 Instruments and techniques
DE: 1699 General or miscellaneous
SC: Union [U]
MN: 2007 Fall Meeting