The following pilot project proposal was developed
by the GIS Steering Committee as part of an effort to test both
a methodology and an organizational model for developing a PLSS
base map for counties in the State of Nebraska.
The challenges associated with developing a PLSS
base map for the large, primarily rural areas of Nebraska, are
daunting. With approximately 100,000 points, no central state
agency has authority, responsibility or resources for this type
of effort. Nebraska also has very little in the way of federally-owned
lands, and consequently little in the way of federal resources
is available to apply to such an effort. In Nebraska, the responsibility
for the maintenance of the PLSS rests largely with county governments,
and with county surveyors where they exist. In addition to these
other factors, Nebraska's local governments are operating under
tight spending lids and many of the counties are still largely
in a pre-digital world with their county mapping.
In an attempt to meet these challenges, the pilot
project approach was designed with two key objectives in mind.
One objective was to pool available resources by actively encouraging
interagency partnerships and the other was to segment the overwhelming
size of the task into manageable pieces.
It is important to emphasize that this Pilot Project
Proposal relates to a pilot project which is still in its very
early phases. This Pilot Project Proposal was mailed to all of
Nebraska's county governments (sample letter in Appendix), to
all of Nebraska's Natural Resources Districts, and to several
state and federal agencies with potential interest. The Steering
Committee was pleased with the overall level of interest and response
that it generated. Working within less than a three week timeline
for response, representatives from twelve counties expressed an
interest in having their county considered for the initial pilot
project. Initially expecting to select only one county for the
pilot project, the Steering Committee identified four counties
as showing particular promise. This selection was based on the
criteria outlined in the proposal.
In the month and a half since that initial cut to
four possible counties, outreach and negotiations have progressed
to the point that four county-specific Interagency Agreements
(Adams, Dawson, Hall and Merrick counties) have been signed (see
Appendix for sample agreement). Initial training for GMM software
operators from the four counties has recently been completed (Sept.
1997).
The nitty-gritty PLSS database development effort
is just beginning and much work will be needed, before a final
product can be evaluated. However, this PLSS Pilot Project Proposal
has already proven to be an effective outreach tool to engage
local governments officials and state and federal agencies in
cooperative PLSS database development efforts.
For further information, contact Larry K. Zink, Coordinator, Nebraska GIS Steering Committee, Intergovernmental Data Service Division, 521 South 14th, Suite 101, Lincoln, NE 68508, 402-471-3206, "lzink@doc.state.ne.us".
Nebraska, along with most other states, has historically developed two separate reference systems for land and geographic information. The Public Land Survey System (PLSS) is designed for describing and conveying property, while the National Spatial Reference System (NSRS) supports precise positions and measurement for mapping and other purposes. The PLSS is the underlying legal framework for land ownership and land ownership records in the State of Nebraska. The PLSS in Nebraska is based on approximately 100,000 section, quarter-section and other original government corners originally surveyed and monumented roughly 100 years ago.
For accurate mapping of land ownership and to enable the integration
of land ownership information into modern land information systems,
it is important to be able to relate the legal locations of the
PLSS to the mathematical framework of the NSRS (latitude/longitude).
This proposal is for a pilot project to develop and test a methodology
and an organizational model for capturing this framework data
in a digital format suitable for use in modern computerized record-keeping
and analytical tools.
The long-term goal of the pilot project is to lay the foundation
for the development and maintenance of an upgradeable, statewide,
PLSS database with standard IDs and coordinates for PLSS section
and quarter-section corners and parcels. Such a statewide database
would provide the foundation for building a PLSS base map for
local government land record modernization efforts and for a wide
range of other applications requiring land ownership information.
In pursuit of this long-term goal, the pilot project will develop
(for a selected pilot project area) a PLSS database with estimated
latitude/longitude coordinates for PLSS corners. Prudent management
of public resources calls for a database development approach
based on a reasonable compromise between the need for spatial
accuracy and the related development costs, coupled with the ability
to upgrade the database as the need for spatial accuracy increases.
This upgradeable approach to PLSS database development is a practical
one, because of the built-in capability in the software/database
design, to enhance the spatial accuracy of the calculated corner
coordinates as additional and more accurate spatial information
becomes available.
The initial pilot project corner coordinate estimates will be
based on a combination of information from digitized quad maps,
original government surveys, and Global Positioning System (GPS)
readings on a sampling of PLSS corners. These estimated coordinates
will be calculated with aid of computer software designed to follow
the specified procedures for restoring lost or obliterated PLSS
corners, as outlined in the Bureau of Land Management's 1973 Manual
of Instructions. The database resulting from this initial phase
will be a significant enhancement to PLSS databases currently
available for most areas of the state and will be suitable for
a wide variety of mapping applications. It is expected that this
initial PLSS database will have a spatial accuracy which will
be suitable for at least medium-scale mapping needs.
Because of resource limitations, additional information from private
surveys and GPS readings on every PLSS corners that might be located
will not be incorporated in the initial pilot project corner coordinate
estimates. However, the software/database design will allow for
this additional information to be integrated into the coordinate
calculations as the need for spatial accuracy increases and additional
resources become available. This upgradeability will allow local
governments (or others) to develop a PLSS base map suitable for
all mapping scales, by building on the substantial investment
already made in this initial PLSS database.
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Private property ownership is a fundamental element in the structure of our society and its economy. Information about land ownership, and the associated rights and responsibilities, is needed in a wide range of activities: real estate transactions, taxes, zoning, banking and insurance, food production, natural resources management, transportation planning, utilities, etc. Consequently, considerable resources are invested by both the public and private sectors to maintain current, accessible land ownership information.
In Nebraska, the Public Land Survey System (PLSS) (townships and sections) is the legal framework for determining land ownership boundaries. To store land ownership information and integrate it with other types of information in modern information systems, such as Geographic Information Systems (GIS), it is necessary to have the locational coordinates (e.g. latitude/longitude) on these PLSS section corners. The purpose of this pilot project is to develop and test a practical methodology and organizational approach for collecting/computing these PLSS corner coordinates. This pilot project, and the related development of a statewide PLSS database as envisioned by the pilot project, offers the following benefits:
The framework for determining land ownership boundaries, the PLSS,
is based on original government surveys that subdivided the land
into an approximate one-mile square grid (sections). As part of
these original surveys, the location of most of these section
corners was marked with some type of physical monumentation. Over
the years, a high percentage of these monuments have been lost
or obliterated. Locating and/or restoring these original corners
is complicated by the wide variance in the quality of the original
surveys. Because of the variance in these original surveys, one
cannot assume that original corners were located at exactly one-mile
intervals, nor that they were located on the originally intended
straight line grid. Regardless of whether these monuments are
lost or obliterated, or whether they were accurately placed originally,
their original physical location, based on the best available
evidence, is still the primary legal controlling factor in
determining the boundaries of land ownership parcels today.
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A map showing the PLSS corners, and their coordinate locations,
is commonly known as a PLSS base map. A PLSS base map is the foundation
data layer that local governments need to associate other land
ownership information with specific locations on a map. Because
land ownership information is needed for a wide range of activities
in state, local and federal government agencies and in the private
sector, there is an increasing need and demand for accurate information
on the coordinate locations of PLSS corners. The Federal Geographic
Data Committee (FGDC) recognized the importance of this information
when it designated the PLSS database as one of seven "framework"
geospatial databases it prioritized for development.
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One standard methodology for capturing the coordinate locations
of surface features over a broad area is to use aerial photography
and photogrammetric techniques. The use of these techniques for
capturing PLSS corner coordinates is handicapped by the difficulty
of identifying PLSS corners on an aerial photograph. If the PLSS
corners were located in advance of the photography and marked
with targets that would ultimately be visible in an aerial photograph,
this approach would be workable. However, if the data is needed
for a wide area, the size of this task also makes it impractical
for most entities. Another possible approach is to use aerial
photography to determine the coordinates of visible surface features
that are frequently associated with PLSS corners (road intersections,
fence lines, field boundaries, etc.) While this approach will
work for some limited applications, it is one that should be employed
very cautiously. In Nebraska, road intersections and fence lines
are frequently associated with PLSS corners, however, the degree
to which these locations correspond to the original PLSS corners
varies greatly. Building a multipurpose land information system
based upon the assumption that the PLSS corners are co-located
with road intersections and fence lines, ultimately means that
those systems are built upon a foundation of questionable accuracy.
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Coordination and Cooperation Needed
for PLSS Database Development. In designating the
PLSS database as a "framework" database, the FGDC noted
the need for coordination and cooperation from a cross-section
of the public sector in the development and maintenance of this
database. In most cases, the most accurate information about local
PLSS corners resides with the local County Surveyor. However,
in many cases the local government has neither sufficient resources
to collect the corner coordinates by itself, nor is it necessarily
the highest priority for the local government. This illustrates
both the importance of working with local governments to develop
the PLSS database and of developing mechanisms to share the initial
costs for its development. The need for a compatible or seamless
PLSS database that extends beyond the jurisdictional lines of
a local government, is another compelling reason for coordination.
To meet the needs of the broadest community of potential users,
PLSS coordinate data should be developed in a standard format,
with a standard system of corner IDs, and integrated across jurisdictional
lines. To be successful, a PLSS pilot project must develop and
test organizational models capable of facilitating the necessary
coordination and cooperation between public entities.
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Another approach to segmenting the task is to develop a system
in which the quality of the PLSS coordinate data can be upgraded
over time. Software and database models have been developed to
allow for the upgrading of PLSS databases, through the later incorporation
of more accurate coordinate values for individual PLSS corners.
The more sophisticated software of this type, allows a user to
quantify the relative accuracy of different measurements, and
to readjust all the PLSS coordinates, in a given area, when more
accurate measurements are incorporated into the database.
Such an approach to PLSS database development makes it reasonable
to consider investing in the initial development of a PLSS database
which has a spatial accuracy suitable for most medium-scale mapping
applications. The ability to upgrade the spatial accuracy of the
PLSS database, without losing the benefits of the initial investment,
provides a strong argument for this upgradeable approach when
available resources are limited. Such an approach, provides an
avenue for a variety of public and private entities to cooperate
in an ongoing effort to upgrade the spatial accuracy of the PLSS
database by incorporating GPS readings taken on individual PLSS
corners, in the normal course of their work. This approach also
provides a solid foundation upon which a local government (or
another entity needing higher spatial accuracy) can build a PLSS
base map suitable for large-scale mapping, such as tax mapping.
Systematic collection of GPS readings on additional PLSS corners,
incorporating them into the database, and adjusting the database
accordingly, will enhance the spatial accuracy of a PLSS base
map for a given area.
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Through the recorded surveying measurements between multiple PLSS corners, a complex interconnected web of measured and computed relationships exists between those corners. Survey-based cadastral development software uses these mathematical relationships between PLSS corners to determine PLSS corner coordinates. Over the years, due to improving equipment and the varying skills of individual surveyors, the quality of individual surveys has varied considerably. Part of the art and/or science of a modern surveyor is to factor into their calculations the varying quality of these earlier surveys to determine the "best available evidence." Sophisticated survey-based cadastral development software has the capability of considering both the mathematical relationships between multiple PLSS corners and the varying qualities of specific survey information to derive a mathematically-based "best fit" determination of PLSS corner coordinates. It is these same capabilities that provide the ability to upgrade a PLSS database with new, and more accurate surveying measurements.
This pilot project to develop and test a methodology and an organizational
model for developing a statewide PLSS geospatial database is a
cooperative effort between the Nebraska GIS Steering Committee
and the Nebraska State Surveyor's Office. The GIS Steering Committee
passed a resolution endorsing the concept of a PLSS pilot project
and creating an Advisory Committee to seek partners and develop
an action plan at its May 20, 1997 meeting (see Appendix). This
motion was consistent with a standing GIS Steering Committee priority
of helping to facilitate land record modernization efforts at
the local government level. The pilot project is also consistent
with the Steering Committee's duties to make recommendations to
the Legislature for program initiatives and funding; and to establish
guidelines and policies for statewide GIS operations and management
to include the acquisition, development, maintenance, quality
assurance such as quality control standards, access, ownership,
cost recovery, and priorities of databases.
During the initial planning phase, the pilot project will be directed
by an Advisory Committee of the Nebraska GIS Steering Committee
consisting of Jim Brown, State Surveyor and GIS Steering Committee
Chair; Duane Stott, Scotts Bluff County Surveyor; Larry Worrell,
Lancaster County Surveyor; and Larry Zink, GIS Steering Committee
Coordinator. Additional committee members will be added as a pilot
project county is selected and as additional organizational partners
are identified.
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Solicit Support. The
primary focus of the pilot project will be develop and test an
approach for developing an upgradeable PLSS database, in the context
of developing a PLSS database for a selected county or counties.
Since the necessary resources to conduct such a pilot project
are not currently available, and since one of the objectives of
the pilot project is to develop institutional models for facilitating
such an effort, one of the earliest efforts will be to market
the pilot project proposal to public and private entities, soliciting
their active support and participation in a pilot project.
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According to the software manual, GMM was developed to satisfy the need for an accurate and complete set of geographic coordinate data for PLSS corners. Specifically, GMM was developed to:
PLSS Database Development. Actual PLSS database
development will involve five major phases. The initial phase
will establish the basic framework for the PLSS database and import
PLSS corner coordinates that have been digitized from USGS 7.5
minute paper quad maps. If the GMM software is used, PLSS database
development will proceed in PLSS township groupings. In the next
phase, the surveying measurements, and related information, from
the original and resurvey federal government survey records will
be entered. This information is currently in a non-digital format,
and as such, its input will require significant resources. As
part of this data input process, estimates of the spatial accuracy
of data will be associated with data from both the digitized quads
and the government surveys.
Once these two initial data entry phases have been completed,
GMM software utilities will be used in the third phase of PLSS
database development, making an initial determination of PLSS
corner coordinates. As part of this interactive adjustment process,
the software presents a range of options for determining the "best
fit" of the PLSS corners. Since these options are based on
surveying techniques and procedures, it is highly recommended
that someone familiar with surveying techniques and procedures
is closely involved in this process. This "best fit"
adjustment process calculates PLSS coordinates on a township by
township basis. Following completion of the initial calculation
of PLSS coordinates for each township, other GMM software utilities
will be used to integrate and balance regionally, all of the county's
townships together.
To facilitate the efficient collection of these GPS readings,
the pilot project design assumes the cooperative support of the
local County Surveyor to locate and flag targeted PLSS corners,
in advance of a GPS crew arriving in the pilot project area. GPS
equipment and/or a GPS crew will likely be needed to assist the
local County Surveyor to occupy these PLSS corners and collect
readings. If the location of additional PLSS corners is known
and sufficient GPS resources are available, GPS readings may also
be taken on additional corners to provide a quality check on the
final results of the PLSS database.
Following post-processing of the GPS readings, the GPS-determined
coordinates for approximately two found PLSS corners per township,
with their associated spatial accuracy estimates, will be incorporated
into the PLSS database. In the fifth and final phase of the PLSS
database development, the software utilities will again be used,
in a repeated interactive process, to recompute all the PLSS coordinates
for each township, adjusting for the new, and more accurate GPS
corner coordinates. This township by township process will be
followed again by a regional balancing of the townships to incorporate
them all into one seamless county PLSS coordinate database. To
assess the impact of incorporating the two GPS corner readings
per township, the PLSS coordinates calculated after incorporating
the GPS readings will be compared to those calculated prior to
incorporating those readings.
With the recalculation of PLSS corner coordinatesfollowing the
incorporation of the two GPS corner readings per townshipthe five
phases of the basic PLSS coordinate database development planned
as part of the pilot project will have be completed. If the resources
were available to collect GPS reading on additional PLSS corners,
that information would be used as a quality check on the final
calculated PLSS corner coordinates.
As a final step, the PLSS data generated as part of the pilot
project will be translated into database formats that can be imported
into common GIS software (ArcInfo and Intergraph) that are commonly
used in multi-purpose land information systems. This step will
permit the evaluation of these software translation modules and
the identification of any PLSS database design changes that might
facilitate this translation and importing into a broader land
information system.
To establish a baseline to estimate the requirements for efforts to develop a PLSS database for a broader area, the time and resources required for the pilot project area will be compiled, analyzed, and summarized. In a similar vein, experiences in the organizational/institutional component of the project will be analyzed and recommendations made for future efforts in a final pilot project report. If sufficient resources are available, the PLSS data digitized from the paper quads maps outside of the pilot project area will be incorporated into an initial GMM control database. This would provide a foundation for follow-up PLSS database development efforts in other areas, and an interim statewide PLSS reference database with standard PLSS IDs and approximate coordinates.
Estimate based on an average county pilot project area of 24
townships
| Outreach to and coordination of pilot project partners | in-kind * | ||||
| . | |||||
| Software training and limited support | |||||
| BLM | in-kind BLM * | ||||
| Pilot project personnel | $1,400 | ||||
| . | |||||
| Digitized PLSS corner coordinates from 7.5 minute quad maps | in-kind * | ||||
| . | |||||
| Data entry of original government survey information | |||||
| personnel (current estimation, one-week /township, $9/hr) | $8,600 | ||||
| office | in-kind * | ||||
| computer | in-kind * | ||||
| expenses | in-kind * | ||||
| . | |||||
| Computer operator of cadastral software | in-kind * | ||||
| PLSS pilot project coordinate determination/adjustment process (twice) | |||||
| PLSS pilot project parcel generation | |||||
| Translate PLSS data into GIS data formats | |||||
| Incorporate digitized PLSS coordinates into statewide reference database | |||||
| . | |||||
| Surveyor supervision | in-kind * | ||||
| Original government survey data entry | |||||
| Cadastral software adjustment process (twice) | |||||
| Quality control and assessment | |||||
| . | |||||
| GPS control | |||||
| Flagging, and guiding GPS crew to PLSS sampling/control corners | in-kind * | ||||
| GPS equipment and/or crew | in-kind * | ||||
| Post-processing of GPS reading | in-kind * | ||||
| Data entry of GPS corner control points | in-kind * | ||||
| . | |||||
| Final report generation | in-kind * | ||||
* in-kind implies an expectation that actual services
will likely be provided in-lieu of a direct cash contributions
from a project partner. In most instances, the costs of the actual
service is not known because the pilot project area has not yet
been selected and because of limited direct experience with this
type of effort. One of the objectives of the pilot project is
to provide baselines for these cost categories for future efforts.
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1. Organizational Development Pilot Project
2. PLSS Coordinate Database Development Pilot Project
3. Quality Control/Evaluation and Enhancement of PLSS Coordinates Pilot Project
4. Development of Final Pilot Project Products -- (completed GMM files and maps, if this software used)
Section 1. Authority
The Advisory Committee on the Statewide Public Land
Survey System is created pursuant to Section 81-2603, R.R.S. 1943.
Section 2. Purpose
The Public Land Survey System (PLSS) is the underlying
legal framework for land ownership records in the State of Nebraska.
A wide range of private and governmental functions depend on information
about land ownership, including real estate transactions, taxes,
zoning, banking, insurance, food production, natural resources
management, transportation planning, and utilities.
Computerized tools, such as geographic information
systems (GIS), can assist in the management and analysis of land
information. These can integrate and analyze a wide variety of
information, based on the physical location of different features
and characteristics. An accurate coordinate location (e.g., latitude
and longitude) for each PLSS corner is needed to fully integrate
land ownership information into computer programs. Because of
the growing importance of accurate coordinates for PLSS corners,
the Federal Geographic Data Committee has designated the PLSS
database as one of seven priorities.
Developing a statewide PLSS database in Nebraska
faces two major problems. One is the large task involved in assigning
coordinates to approximately 100,000 section corners. The other
is the high percentage of section corner monuments that are lost
or obliterated. Locating or restoring these monuments is often
difficult, especially because wide variance in the quality of
the original surveys means that corners and monuments are not
always at exact one-mile intervals. The amount of time and work
required to correct these deficiencies will make developing a
PLSS database a continuing effort over a long duration.
The purpose of the PLSS pilot project is to test
a process for developing a statewide PLSS database through a gradual,
iterative process.
Section 3. Charge of the Advisory Committee
The advisory committee shall undertake the following activities:
Section 4. Membership and leadership
The chair of the GIS Steering Committee shall nominate
members of the advisory committee. Those who accept shall serve.
The advisory committee may invite anyone to participate on a non-voting
status. Advisory committee members may elect a chair who shall
be a member. Members shall agree on a manner of conducting its
business.
The chair of the GIS Steering Committee shall provide
or arrange administrative and financial support for the work of
the advisory committee, subject to available resources.
Section 5. Duration
The advisory committee's existence commences when
this resolution is passed and concludes six months later. GIS
Steering Committee may extend the duration of the advisory committee.
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TO: Nebraska County Clerks
FROM: Jim Brown, Nebraska
State Surveyor
DATE: June 12, 1997
RE: Invitation to Participate
in a PLSS Pilot Project
The Nebraska Geographic Information Systems (GIS)
Steering Committee and the Nebraska State Surveyor's Office are
writing to inform county officials of a proposed pilot project
to develop a Public Land Survey System (PLSS) database for a selected
county in Nebraska. This project is intended to produce coordinate
values for the section corners which the county can maintain and
improve. We would appreciate your assistance in distributing the
enclosed Pilot Project Proposal to the most appropriate official(s)
in your county. This is probably the county official with the
greatest interest in updating county maps and/or exploring the
possibilities of developing a GIS for the county. In some counties
this maybe the Assessor, in others the Surveyor, Register of Deeds,
County Commissioner, or a combination.
In Nebraska, the PLSS is the underlying legal framework
for land ownership and land ownership records. To enable these
land ownership records to be brought into modern computerized
land information systems (such as GIS), it is necessary to first
determine the locational coordinates (latitude/longitude) of these
legal PLSS corners. The enclosed pilot project proposal is designed
to develop and test a methodology for collecting/computing these
coordinates. In the course of the proposed pilot project, the
PLSS corner coordinates will be estimated for the pilot project
county.
Because no specific appropriation or grant has been
made to develop this database, and because this PLSS data is potentially
desired by several entities, it is hoped that several partners
can be found to jointly support a pilot project to develop a PLSS
database for a selected county. For such an effort to be feasible,
an interested county would need to be an active partner in the
project and contribute to the resources required. Project resource
contributions could be in the form of funding and/or in-kind contributions,
such as labor.
The enclosed Pilot Project Proposal provides an overview
of the proposed PLSS database development effort and an outline
of the project resources that will be needed. The Proposal also
lists some of the criteria that will be considered in selecting
a pilot project county.
The Advisory Committee charged with developing an action plan for the pilot project consists of the following individuals. Please feel free to contact any of these people for additional details.
Jim Brown State Surveyor and Chair of the GIS Str. Cmte. (402) 471-2566
Duane Stott Scotts Bluff County Surveyor and member of the GIS Str. Cmte. (308) 436-6654
Larry Worrell Lancaster County Surveyor and member of the GIS Str. Cmte. (402) 441-7681
Larry Zink Coordinator, Nebraska GIS Str. Cmte. (402)
471-3206
Because of our desire to move this pilot project
promptly forward, we request that any county wishing to be seriously
considered for selection as a pilot project area, indicate their
interest in a letter to Larry Zink, Intergovernmental Data Services
Division, 521 South 14th, Suite 101, Lincoln, NE 68508.
This initial letter of interest should be received by June
30, 1997.
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