THE LANDSAT LEGACY: TRACKING DOWN THREE DECADES OF KNOWLEDGE
Laura E. Rocchio, Support Scientist, SSAI
Gail M. Hodge, Senior Information Scientist, IIA
Terry Arvidson, Project Engineer, Lockheed Martin
Darrel L. Williams, Landsat Project Scientist, NASA
James R. Irons, LDCM Project Scientist, NASA
NASA Goddard Space Flight Center
Code 614.4 | 292 | 428.1 | 614.0 | 614.4 (respectively)
Greenbelt, Maryland 20771
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
ABSTRACT
Given the tumultuous history of the Landsat Project, the Landsat Project Science Office (LPSO) has initiated the
creation of a Landsat document archive. The project has been dubbed the Landsat Legacy. Since the first earthobserving Landsat satellite was launched in 1972, the program has been variously administrated by a multitude of
government agencies and a private company – consequently, Landsat program documentation is widely
disseminated. In the summer of 2004, the LPSO teamed with the NASA Goddard Space Flight Center Library and
the U.S. Geological Survey to create an archive of essential Landsat documentation for future generations to
reference. The archive will eventually house policy-, technical- and science-related documentation. Journal articles
and other privately copyrighted materials are outside the scope of this project. To gather the over 35 years worth of
documentation, the LPSO is soliciting program affiliates for Landsat-related materials that have been stored in
personal archives. In early February 2005, the Goddard Library completed construction of the database
infrastructure needed to accommodate the Landsat Legacy archive. Then in August 2005, the Landsat community
was invited to register appropriate documents for potential placement in the new repository. The LPSO will review
these registered documents, select appropriate materials, and subsequently contact potential donors to arrange a
method of document submission. It is the ultimate goal of this project to have an online freely-accessibly archive of
Landsat documentation that can be used by the general public by 2006. This paper reports on the scope, challenges,
and successes of the Landsat Legacy endeavor.
INTRODUCTION
Landsat Legacy Inception
At an early summer biweekly Landsat Project Science Office (LPSO) meeting in 2004, the meeting leaders
commented that a book regarding Landsat’s storied past should be written. It was decided that if such a tome were
to be authored, historical documentation about the Landsat project would need to be gathered. A member of the
LPSO Education and Public Outreach group seized upon this statement, contacted the Goddard Library, and a
collaborative effort to preserve the legacy of Landsat was born.
Landsat Legacy Evolution – A Shifting Definition
After a series of exploratory talks, goals for the project – dubbed the Landsat Legacy – were refined and the
collaborative roles of the LPSO, U.S. Geological Survey (USGS) and Goddard Library were outlined. The
collaborators, or Landsat Legacy team, determined that preservation of the Landsat project history was twofold. It
required that (1) all of the technical documentation from the project be found, digitized and placed in a singular
repository and (2) oral histories be conducted to capture both unrecorded details and the general zeitgeist of the
project as it progressed through the last four decades. The type of documentation sought for the Landsat Legacy
archive includes policy-, technical-, and science-related materials with an emphasis on internal technical papers (or
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grey-literature) of both the government and the aerospace industry. Journal articles and other privately copyrighted
materials are outside the scope of the project because they are easily accessible through institutional libraries.
Project Impetus One: The History of Landsat
For 33 years, the Landsat program has collected spectral information from Earth’s surface, creating an
unparalleled historical archive (unmatched in quality, detail, coverage, and length), but despite Landsat’s technical
triumphs its history has been called more political than technical and the history leading to the creation of the
Landsat program in the 1960s is still somewhat obfuscated.
As stated by Dr. John Barker, Landsat Associate Project Scientist, “the Landsat program was created in the
United States in the heady scientific and exploratory times associated with taming the atom and going to the Moon.”
The first photographs of Earth’s land surface by the Mercury, Gemini and Apollo missions garnered appreciation of
terrain data from space and have been documented as an inspiration for the Landsat program (Lowman, 1999). Yet,
anecdotal stories still exist, one crediting weather satellite suppliers with the suggestion of readjusting the sensor
dynamic range of weather satellites to be optimized for terrain reflectance (instead of cloud reflectance), and another
citing the need for Mars reconnaissance missions to understand the signs of life from space on Earth before finding
them on Mars (Landgrebe, 1997). The Legacy archive hopes to gather as much historical information as possible to
help future historians decipher the evolution of the Landsat concept.
Whatever the project stimulus, when Landsat-1 was proposed, it met with intense opposition from the Bureau of
Budget (which considered high-altitude aircraft the fiscally responsible choice for Earth remote sensing), the
Department of Defense (which feared that a civilian program such as Landsat would compromise the secrecy of
their reconnaissance missions) and from the State Department (which was concerned about the geopolitical
ramifications of photographing foreign countries without permission) (Mack and Williamson, 1998). Meanwhile, the
USGS grew impatient with NASA’s slow methodical investigations of Earth remote sensing; so, in 1966 the
Secretary of the Interior, Stewart L. Udall, announced that the Department of the Interior (DOI) was going to
proceed with its own Earth observing satellite program (Johnson, 1998). This savvy political stunt coerced NASA to
expedite the building of Landsat; Landsat-1 was finally launched in 1972, heralding a new age of remote sensing of
land from space.
This rich and storied history only touches on some of the major epochs of the Landsat-1 project. The events
preceding the launch of each Landsat satellite are equally as involved and nuanced and beg both policy
documentation and oral histories for a complete understanding of events.
Project Impetus Two: The Landsat Technical Phylogeny & Shifting Operational Management
While there has been some limited success by NASA and USGS to encapsulate the Landsat policy decisions in
definitive historical publications, the technical documentation – encompassing engineering, science, and operational
information – is still widely dispersed. The dispersion is partially a result of the altering program management of the
project. NASA, USGS, NOAA, and the private company Earth Observation Satellite Corporation have alternately
administered the Landsat project; therefore, each of these entities was once responsible for Landsat technical
information dissemination. Some loose protocols for publishing User Notes and the like were followed, but there is
not a singular archive where all of these documents can be found. Landsat sensors have evolved over the years and it
is important to understand this progression of technology (both the specifications and nature of these technical
advances). The importance of such technical information can be best illustrated through the three recent scenarios:
(1) A researcher needed to find out which Landsat satellite had acquired a specific scene and on what date.
Through an educational workbook published in 1982, the seemingly archaic scene naming convention was
deciphered (it followed the E-ADDDDE-HHMMS-B format where E stood for “encoded project
identifier,” A stood for the number of the Landsat mission, DDDD stood for the acquisition day number
relative to launch date, HH stood for hour at time of observation, MM stood for minute and S stood for tens
of seconds; B stood for Landsat spectral band number).
(2) The USGS National Center for Earth Resources Observation & Science (NCEROS) has a robust archive of
early Landsat data. During the summer of 2005, NCEROS managers noticed a number of artifacts with
Landsat 3 scenes that were collected soon after launch, so documentation of the on-orbit checkout period
for the first four Landsat satellites is needed.
(3) To determine the geographical nature of the early Landsat data archive – such as no MSS coverage of
Canada in 1980 and 1982 and no Hawaiian data between the years of 1980-1988 – Landsat staff had to
conduct interviews with early USGS data archivist and program managers in September 2003, scour
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Landsat newsletters published by the various Landsat operating agencies, and revisit the minutes of
meetings held through the years with International Ground Station managers.
ARCHIVE IMPLEMENTATION
Project Work Flow
After the Landsat Legacy project
scope was defined, a document collection
strategy was developed. Because the
targeted documents are widely scattered, it
was decided that the best method to gather
the materials was to ask Landsat program
associates to donate related documents that
have accumulated in their personal
archives over the decades. A list of
potential donors was established. Then, to
accommodate
the
potentially
vast
quantities of materials, much of it possibly
duplicative in nature, it was decided that
the donors should first be asked to register
their documents, as this would afford a
screening process to take place before
committing any materials to the Legacy
archive.
Registered documents will receive a
rating based on physical attributes, but a
review committee will determine if a
document should become part of the
archive based on the scope and uniqueness
of its content.
After establishing a method of
document collection, an organization
scheme was necessary. Metadata standards
Figure 1. Landsat Legacy workflow model.
were developed to aid in the organization
of documents. Using these metadata fields, an online registration system was designed. The registry will be open for
approximately 6 months over which time the Landsat Legacy review committee will decide on the fate of each
registered document. A method of submission must be decided for accepted documents. Hardcopy submissions will
need to be scanned and stored. Concurrently, oral histories will be conducted and an exhaustive list of important
Landsat resource repositories will be created. Each of these steps will be further evaluated in the following sections.
A Unique Archive
The Landsat Legacy archive is atypical because it relies on both the registration and donation of documents held
in the personal collections of Landsat affiliates. The project is beholden to the generosity of these affiliates, as they
must be willing to sort through their documents, register them, and then submit them. Additionally, affiliates are
asked to consider participating in an oral history or interview.
Information Infrastructure
An archive is only as good as its content and the user’s ability to access that content, as such, accurate and
descriptive content metadata is essential for a successful document repository. Access to the Landsat Legacy digital
document collection will be provided by the Digital Asset System (DAS) developed by the Goddard Library to
organize metadata records. All Legacy metadata records are based on the Goddard Core Metadata template; the
template has been extended to accommodate Landsat-specific terms.
Nineteen metadata fields from the Reduced Goddard Core Metadata template (including essential basics such as
title, description, and publisher) have been selected for the Legacy project. Of these 19 fields, four have been
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tailored for Landsat-specific pull-down menus that have a controlled vocabulary. These fields include “Missions,”
“Instruments,” “Audience,” and “Subject Competencies.” The “Missions” field includes the ten names that describe
the Landsat satellite missions, from Landsat 1 through LDCM, and can be extended to include future missions. The
“Instruments” field lists the eight sensors that have flown on (or at one time been planned for) the Landsat missions;
this field is also extendable. The “Audience” field is intended as a search filter that will allow users to restrict their
search based on perceived audience-oriented needs. This field currently includes twelve terms. The library defines
“Subject Competencies” as “the name of the vocational or technical specialty that is relevant to the content of the
resource.” This metadata field covers all of the Landsat-associated terms ranging from “applications” to
“spacecraft.” There are 16 major categories, but these categories have been further divided into 214 subcategories.
Selecting the controlled vocabulary for “Subject Competencies” was an iterative process. The Legacy staff
composed the original list, which was reviewed, edited and augmented by eight Landsat scientists and engineers.
The robustness of the controlled vocabulary will influence the ease and accuracy of future archive-user
searches. To assure the consistent categorical assignment of each document, each of the Landsat-specific terms must
be explicitly defined. Lori Finch, a thesaurus coordinator of the National Agricultural Library, has collaborated with
the Legacy staff to create professionally worded definitions (or scope notes as they are known in library science) for
each term. As of late August 2005, scope notes have been developed for 55% of the 260 total terms.
The Search for Legacy Donors
Because the Landsat Legacy archive is relying heavily on the donation of documents from past Landsat
program affiliates, an exhaustive donor list made up of seminal Landsat employees, managers and advisors was
developed. The initial listing was inherited from the 2003 Sioux Falls Landsat data archive interview attendee list.
The list was then circulated to current Landsat managers and senior scientists to generate additional names. Contact
with the donors has spurned yet more names. Every person on the Legacy contact list was associated with the
Landsat project in some capacity be it via field campaigns, project management, calibration work, scientific
research, engineering, software-development, or international data collection. Currently, 211 members of the
Landsat community are on the donor list; contact information is still needed for 37 people. Fifty donors have been
designated as Landsat Veterans. The Landsat Veteran title is applied to those who have been associated with the
Landsat project for more than two decades and who have, or may soon, retire.
Donor Reactions
In late January 2005, a letter went out to the Landsat Veterans to inform them of the upcoming Legacy project
and to ask them to contact the Legacy team if they planned to purge documents before the Legacy document registry
opened in the summer. The sampling of responses listed below indicates both interest in the project and a vast
quantity of materials within the community:
(1) “I have written three NASA Publications that deal with Landsat… I would be pleased to send copies of
these for use in your project,” author of three definitive NASA publications: Mission to Earth, The Landsat
Tutorial Workbook, and Geomorphology from Space.
(2) “I’m definitely a Landsat veteran and have materials buried away in boxes in my basement that might be
good candidates for the Legacy library,” former chief of the USGS EROS Data Center.
(3) “I have many file drawers and boxes of Landsat management policy paperwork dating back to 1970 and
ERTS 1,” former chief of the Earth Observations Program Office at NASA/JSC.
(4) “I have materials going all the way back to the era of ERTS,” longtime Landsat Science Office member.
(5) “I have a lot of material I would be glad to contribute or lend to the proposed Legacy project,” early
Landsat cartographer and early Landsat field campaign participant.
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Registry Development
The Legacy registration system enables
donors to register their documents. After
document registration, the Legacy team can
evaluate which documents are appropriate
for the archive. The registration process
involves the potential donor entering basic
information about each of his or her
documents. A subset of the Legacy
metadata template is used for document
registration. Information is also collected
about the file size (be it digital) or the
document condition (be it hardcopy).
Donors enter this information into an online
registration form. The form was designed
by Goddard library programmers and
written in ColdFusion, JavaScript, and
HTML with a MySQL database backbone.
The registration interface was tested with
historical Landsat documentation donated
by a local Landsat Veteran. Testing enabled
the Legacy team to insure automated
Figure 2. The Landsat Legacy document registration website.
responses were correctly issued, that
database translation went smoothly, and
that there were no overt errors.
The document registry is the first interface for the potential donors so it must be user-friendly and aesthetically
pleasing as well as functional. The site’s public interface was designed and coded by the LPSO. The site officially
opened on August 1, 2005 at http://library.gsfc.nasa.gov/landsat. On August 5, 2005, an email was sent to 172
potential donors – others on the contact list either have no contact information or were mailed a letter via the U.S.
Postal Service.
Review of Registered Documents
Because much of the Landsat history took place before desktop computers and the Internet became ubiquitous,
it is expected that the majority of materials will be in hardcopy format. To ensure that no donor is asked to submit a
duplicate document, documents will be reviewed for content scope and uniqueness, as well as document condition.
The Legacy team uses a simple algorithm to assign a physical attribute rating to each hardcopy document based on
information supplied during the registration process (such as: Is the document bound or unbound?, What is the
condition of the document?, Is the document an original or a photocopy?). To ensure that the accepted documents
are in the purview of the Legacy project, a six-person review committee has been appointed to make the final
decision of whether a document should become part of the archive.
Document Digitization
Once a registered document has been accepted and submitted, it will be scanned if it is not already in a digital
format. The Goddard Library has a range of sample materials including Thematic Mapper Final Report, First Draft,
September 1984, The Landsat Tutorial Workbook: Basics of Satellite Remote Sensing, Landsat 2 Reference Manual
and the Landsat D 1982 full-color brochure – as well as other materials – for digitization testing.
The library staff has gathered data on the necessary scanning time per page using the modern scanning
equipment at NASA’s Wallops Flight Facility – (these scanners can scan two sides of a page at once and similar
machines have just been purchased by the Goddard Library). With existing technologies such as optical character
recognition (OCR) and exciting new technologies such as the archive.org-type robot, there have been drastic time
and cost reductions of book scanning and indexing.
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Oral Histories
The Landsat Legacy project plans not only to archive digital documents. Oral histories will be another
important part of the repository. Oral histories will consist of interviews with Landsat veterans. They are intended to
preserve the historical context of the Landsat missions. Group interviews of between six and ten people will be
arranged. The group dynamic is hoped to spark memories. After the August registration notice was circulated, a
Landsat Veteran contacted the Legacy team and advised a reduced timeline for the oral history scheduling because
many of the Landsat forbearers are now octogenarians.
The Legacy team is now finalizing logistics for oral history venues and required permission release forms –
participants will be able to decide if restrictions are needed and they will be given some level of editing rights. The
Goddard Library has access to auditorium space (with good lighting and acoustics) and a rather sophisticated A/V
system: two high-definition video cameras, two large portable hard-drives, microphones and lavaliere mikes. The
library also has the means to do video editing (blank slides can be added for names, etc). Importantly, the library’s
videos are searchable, but transcription methodology is still under investigation. If oral histories are conducted in
other geographical locations similar A/V equipment will be needed.
Current Landsat scientists have assembled a compendium of twenty questions to spark conversations among the
oral history participants. While library staff will provide the technical equipment and expertise for the A/V work, a
professional facilitator will be needed.
Survey of Other Resources
In parallel with the oral history and registry efforts, the Legacy team is surveying the existing repositories of
technical Landsat documentation. A rich primary source archive of handwritten notes by the late John Parr Snyder
(father of the Space Oblique Mercator Projection) is managed by John Hessler, a mathematical cartographer from
the Geography and Map Division of the Library of Congress. The division also has 24 boxes of materials from
Alden Colvocoresses concerning early satellite mapping with Landsat. While the Legacy project does not plan to
digitize handwritten documentation, we will provide a listing of Library of Congress holdings for users to reference.
Additionally, Larry Biehl of Purdue University has a robust archive of the work of early digital remote sensing
researchers. And, the Legacy team has recently been told that USGS personnel spent nearly a year organizing early
ERTS documentation (1968-83) which were then sent to the Federal Records Center.
Outreach and Public Awareness
Aside from the direct contact with Landsat affiliates, the Legacy team has published notices in the USGS
“Landsat Update,” and in “The Earth Observer” and “FLAG” publications at NASA Goddard. The team also
presented information about the Legacy project to Landsat international cooperators at the spring 2005 Landsat
Technical Working Group meeting.
PROJECT CHALLENGES
The multifaceted nature of the Legacy project presents many challenges. We have experienced problems
tracking down retired Landsat Veterans and we have run into issues with donor apathy. Given recent U.S.
Government trends regarding Scientific and Technical Information (STI) and International Traffic in Arms
Regulations (ITAR) procedures, all documents made available through the Landsat Legacy archive will have to go
through STI and ITAR reviews. While most materials will easily pass, there are a few subjects that will likely have
ITAR restrictions including: detector technology, spacecraft design, and vendors’ proprietary technology– although,
these restrictions may expire with time. Physical storage is also an issue, if donors truly want to donate boxes of
documentation, a large storage facility may be necessary. There is also somewhat of a race against time as Landsat
Veterans begin to retire and purge dated materials.
NEXT STEPS
The Landsat Legacy project has forged a fruitful partnership between the NASA LPSO, the USGS NCEROS
and the Goddard Library. Together these organizations have been able to donate time and expertise to create a solid
foundation for the archive. The Landsat Legacy has also become a model archive project for the Goddard Library,
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breaking new ground such as mapping the Landsat controlled vocabulary to the NASA taxonomy. Most importantly,
the project has reinforced the commitment and dedication of the Landsat community for the preservation of the
Landsat Legacy.
The target date for the public opening of the Landsat Legacy archive is late 2006. There is much work to be
done in the intervening months. Document registration must be monitored and outreach efforts to spurn donor
contributions will most likely be necessary. The review committee meetings must commence once 50 documents
have been registered. As the review committee decides which documents to accept, every document must be fully
integrated into the metadata database and each hardcopy document must be digitized. An online user interface for
the Landsat Legacy archive must be created and tested. Simultaneously, oral histories must be organized and
conducted and the resulting videos will need to undergo editing and transcription. The survey of related archives
must be completed and the information must be displayed in a functional manner on the Legacy website.
It is intended for the Landsat Legacy archive to continue to grow as future Landsat sensors are launched and as
future employees pick up the Landsat torch that has burned for these past 40 years.
ACKNOWLEDGMENTS
There are a number of people who have made the advancement of the Landsat Legacy project possible. From
the Goddard Library, Nikkia Anderson, Huacheng Tu and Dan Smith have provided library science expertise to
structure this project. Drs. Samuel Goward (UMD) and John Barker (NASA) from the LPSO, and Ron Beck from
the USGS have provided much needed insight. And, Jeannie Allen from the LPSO Education and Public Outreach
group must be credited for championing the idea of the Legacy project and beginning the collaboration between the
LPSO, USGS and Goddard Library.
REFERENCES
Johnson, R. (1998). What it took: A History of the USGS EROS Data Center. Center for Western Studies, Sioux
Falls, SD, pp. 5-7.
Landgrebe, D. (1997). The evolution of Landsat data analysis. Photogrammetric Engineering & Remote Sensing,
63(7):859-867.
Lowman, P. (1999). Landsat and Apollo: the forgotten legacy. Photogrammetric Engineering & Remote Sensing,
65(10):1143-1147.
Mack, P., and Williamson, R. (1998). Observing the earth from space. Exploring the Unknown: Selected Documents
in the History of the U.S. Civil Space Program, vol. 3. NASA, Washington, D.C. pp. 155-178.
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