The Manual of Surveying Instructions, the PLSS Datum, and the Local Surveyor

The Manual of Surveying Instructions, the PLSS Datum, and the Local Surveyor
Presented by: Stephen K. Haddock, PLS, CFedS Witness Tree Surveying Pilot Rock, OR and Bob Dahl, BLM Cadastral Surveyor Division of Lands, Realty & Cadastral Survey Washington, D.C. American Congress on Surveying and Mapping & ESRI Survey Summit San Diego, CA – July 10, 2011 Write down individual’s expectations on attending this presentation. August 2, 2011

Agenda What is the Public Land Survey System (PLSS) Datum
When is it relevant to the local surveyor 1) Law require resurveyors to follow in the footsteps of the original surveyor. 2) Land surveying require correct, consistent, and repeatable measurements. 3) When conducting surveys of parcels derived from the Public Land Survey System (PLSS), a thorough understanding of the gathering and reporting of measurements performed during prior surveys is essential. This presentation describes past and present measurement technology and techniques and the general framework for both the gathering and reporting of measurements of PLSS surveys. 4) The attributes of the PLSS Datum, as described in Chapter II of the Manual of Surveying Instructions (Manual) are defined. 5) Asked and answered are: a) When should the local surveyor survey on the PLSS Datum? b) When is it not necessary? c) What errors (blunders) can be introduced into a boundary survey using a wrong datum? 6) The student should obtain a better understanding of the components of the PLSS Datum and how they impact land surveys.

Principles of PLSS Surveying
Measurements Correct Consistent Repeatable Following in the Footsteps Measurement at Proportionate or Intersection Gathering & Reporting Measurements Past Current Future Principles of PLSS Surveying Measurements Correct Consistent Repeatable Following in the Footsteps Measurement at Proportionate or Intersection Gathering & Reporting Measurements Past (Pre-1910 tables in Survey Manuals; Post-1910 Redbook) Current Future Original Survey/Corner – Any survey/corner that has zero error. Resurvey/Corner – Any survey/corner that can contain error.

Manual of Surveying Instructions
Chapter II – Methods of Survey How is the Manual the same as the 1973 edition? Highlight of “new” issues in the 2009 edition. PLSS Datum component parts with chapter II Manual section(s) citation: Introduction, 2-1. Basis of Distance, 2-2. Basis of Direction, 2-3. Methods of Measurement, 2-4 through 2-8. The Geodesy of Large-Scale Cadastral Surveys, 2-9 and 2-10. True Meridian at the Point of Record, 2-11 and 2-12. Line of Constant Bearing, 2-13 and 2-14. Line of Sight, 2-15 and 2-16. Curvature, 2-17 and 2-18. Convergency of Meridians, 2-19. Lengths of Arcs of the Earth’s Surface, 2-20. Geometric Effects and Apparent Misclosure, 2-21 and 2-22. Area, 2-23 and 2-24. Parallel Lines of the PLSS, 2-25. Elevation, 2-26. Deflection of the Vertical, 2-27 and 2-28. Geodetic Reference System, National Geodetic Survey (NGS) National Spatial Reference System, 2-29. Latitudes and Departures, 2-30. Geographic Positions, 2-31 and 2-32. Grid Coordinate Systems and Coordinates, 2-33 and 2-34. Use of Local Survey Measurements, 2-35 and 2-36. Accuracy of Survey Measurements, 2-37. National Spatial Data Infrastructure (NSDI), 2-38. Statistical Analysis of Survey Data, 2-39. Computations in the PLSS Datum, 2-40. Units of Direction, 2-41. Units of Distance, 2-42 and 2-43. Examples.

Why is the Manual and/or the PLSS Datum Relevant to the Private, County, Tribal, and State Surveyor in Your State(s)? There are two sets of foot steps to follow and one set to leave: (1) the legal and (2) the original surveyor, and (3) computational. The BLM does not make the Manual authoritative to the private practice of land surveying in a State. That is done by the State legislature, State administrative rules, State attorney general opinions, and/or State judicial action. The Manual can be characterized as a collection of general instructions: a) capturing the law and b) stating the “law” (the rules). It is up to each surveyor to determine what force the Manual has in their State and for each survey they are involved with. In the BLM, the final technical determination is made by the authorized official delegated with responsible charge of an official survey, i.e., the BLM State Office Chief Cadastral Surveyor. The BLM Chief Cadastral Surveyor has final interpretation of the Manual. The Manual is part of a Covenant between the Federal Government and its citizens. Why is the Manual relevant to the Private, County, Tribal, and State Surveyor in Your State(s)? The Manual are the survey rules for locating the boundaries and corners of: Lands with public domain status, including Indian trust lands; Federal lands that have never gone to patent; and Federal acquired lands and non-Federal lands, described by a Federal patent or based upon a Federal patent description; typically the Manual is the rules for locating the exterior boundary of the described lands. There are two origins of boundary line creation: (1) Federal and (2) Non-Federal (private) Description example: “east-half” “west-half” - a) Federal; or b) State? Bona fide – Federal authority surveyors must work with “the where” first and just “the who” or “the what” as they pertain to the first. The intended audience of the Manual is the Federal authority surveyor including: The field surveyor; The special instructions writer; The survey reviewer; The draftsman; and The Cadastral Chief.

The Public Land Survey System
May 20, 1785 – The first Land Ordinance enacted by Congress and first description of the PLSS Datum Today – The 2009 edition of the Manual is the latest description of the PLSS Datum 1785 to Today – The Federal statutes, and Instructions and Manuals issued by Surveyors General, GLO Commissioners, BLM Directors, under the authority of the Secretaries of the Treasury and Interior, have described the PLSS Datum

The Manual is: The Rules to Survey the PLSS by
An Expression of Intent when the Federal Government is the Grantor The DOI/BLM Instructions and Directives, and Authority Surveys are governed by the edition of the Manual/Instructions in force at the time a survey was authorized State Law: Upon Adoption by State legislature, administrative rule, attorney general opinion, common law, and/or common practice Chapter I. The General Plan. The Manual. Purpose and Scope of the Manual, Section 1-3. The Manual of Surveying Instructions describes how the system of public land survey system surveys are made in conformance with statutory law and its judicial interpretation. Sections 1-2 & 1-3

MONTANA STATUE LAW Title 76 Land Resources and Use Chapter 3 Local Regulation of Subdivisions Part 4 Survey Requirements § Survey and platting requirements for subdivided lands. All division of sections into aliquot parts and retracement of lines must conform to the Manual of Surveying Instructions Montana Code Annotated Title 76 Land Resources and Use Chapter 3 Local Regulation of Subdivisions Part 4 Survey Requirements Section Survey and platting requirements for subdivided lands. (3) All division of sections into aliquot parts and retracement of lines must conform to United States bureau of land management instructions, and all public survey corners must be filed in accordance with Corner Recordation Act of Montana (Title 70, chapter 22, part 1).

Washington Administrative Code
§ Land subdivision and corner restoration standards. Reestablishment of lost GLO or BLM corners and subdividing of sections shall be done according to applicable GLO or BLM plats and field notes and in compliance with the Manual Washington Administrative Code. Title 332. Natural Resources, Board and Department of. Chapter 130. Minimum Standards for Land Boundary Surveys and Geodetic Control Surveys and Guidelines for the Preparation of Land Descriptions. WAC § Land subdivision and corner restorations standards – Recording. The following requirements apply when a land boundary survey is performed. If, in the professional judgment of the surveyor, the procedures of subsections (1) and (2) of this section are not necessary to perform the survey, departures from these requirements shall be explained and/or shown on the survey map produced. The reestablishment of lost GLO or BLM corners and the subdividing of sections shall be done according to applicable GLO or BLM plats and field notes and in compliance with the rules as set forth in the appropriate GLO or BLM Manual of Surveying Instructions, manual supplements and circulars. Federal or state court decisions that influence the interpretation of the rules should be considered. Methods used for such corner reestablishment or section subdivision shall be described on the survey map produced.

Office of the Attorney General of the State of California 64 Opinions of the Attorney General 224 (1981) Manual of Surveying Instructions is “the authoritative reference book on the subject” of accessories to corner monuments Office of the Attorney General of the State of California Volume 64, Page 224 of the Opinions of the Attorney General (March 19, 1981) When interpreting a California statute, and describing what the term “accessories” meant in the law, the Attorney General cited the Manual of Surveying Instructions as “the authoritative reference book on the subject.”

Minnesota Land Surveyors Association Public Land Survey in Minnesota
State statutes state that the section subdivision methods follow the rules of the Federal Government Subdivision by survey of descriptions which are Federal in origin must follow Federal method down to the smallest size sold Common Practice: Public Land Survey in Minnesota, Prepared by Jesse E. Fant, Department of Civil Engineering – University of Minnesota, in cooperation with Minnesota Land Surveyors Association (February 1970) Page 3. The Minnesota statutes state that the section subdivision methods in Minnesota follow the rules for subdivision of the Federal government. Page 9. For descriptions which are Federal patents Minnesota follow the Federal method. Page 24. “The subdivision by survey of federal lands must follow federal regulations down to the smallest size sold.” Page 25. For patentee descriptions which are subject to Federal statutes: “The rules for subdividing the section into two halves, four quarters, eight half-quarters or sixteen quarter-quarters were established by the Federal Government when the statutes for the sale of such parcels become law. The patentee (or others later) who obtained title to part of the legal subdivision of a section is entitled to the exact ground area that his description fits on the record township plat as defined by the monuments on the ground.” Common Grantor

NORTH DAKOTA SUPREME COURT Nystrom v. Lee, 16 N.D. 561 (1907)
The courts of this state in the matter of restoration of corners and subdivision of sections are governed by the laws of the U.S., and the instructions issued by the officers thereof, in charge of the public land surveys Common Law: North Dakota Supreme Court Nystrom v. Lee, 16 N.D. 561 (1907) “The courts of this state in matters of this kind [retracement, restoration, and subdivision of section] are governed by the laws of the United States, and the instructions issued by the officers thereof, in charge of the public land surveys. Rev. Codes 1905, section 2540 [N.D. Cent. Code ] .” p. 564. Controversy is between two private landowners, over section 27 center lines, 171 ft. E-W and ft. N-S. County surveyor’s method for restoration of the NE, SE, SW section corners and E and S quarter-section corners was found to follow the Manual rules and found competent and prima facie evidence of the location of the original corners.

Randall v. Burk Township, 4 S.D. 337 (1893)
SUPREME COURT OF SOUTH DAKOTA Randall v. Burk Township, 4 S.D. 337 (1893) The rule is well settled that in a resurvey of land originally belonging to the United States, and which it has caused to be surveyed under its authority, such resurvey must conform to the survey made under the authority of the government

Randall v. Burk Township, 4 S.D. 337 (1893)
SUPREME COURT OF SOUTH DAKOTA Randall v. Burk Township, 4 S.D. 337 (1893) The rule is well settled that in a resurvey of land originally belonging to the United States, and which it has caused to be surveyed under its authority, such resurvey must conform to the survey made under the authority of the government Using Ground Penetrating Radar system to locate subsurface monuments.

MANUAL The Manual of Surveying Instructions describes how cadastral surveys are made in conformance with statutory law and its judicial interpretation. (Section 1-3.) The Director of the Bureau of Land Management has the authority to determine what lands are Federal interest lands, what lands have been surveyed, what are to be surveyed, what have been disposed of, what remains to be disposed of, and what are reserved. (Section 1-15.) The Manual - Purpose and Scope of the Manual 2009 Manual § 1-3. (page 2) The Manual of Surveying Instructions describes how cadastral surveys are made in conformance with statutory law and its judicial interpretation. 2009 Manual § (page 5)The Director of the Bureau of Land Management has the authority to determine what lands are Federal interest lands, what lands have been surveyed, what are to be surveyed, what have been disposed of, what remains to be disposed of, and what are reserved. What percentage of your State has been surveyed under the PLSS? Under Federal survey rules?

Chapters Crosswalk 1973 Edition 2009 Manual Ch. 1 - The General Plan
Ch Methods of Survey Ch The System of Rectangular Surveys Ch Monumentation Ch Lost or Obliterated Corners Ch Resurveys Ch Special Surveys and Instructions Ch. 8 - Field Notes Ch. 9 - Plats Ch Mineral Surveys Ch The General Plan Ch Methods of Survey Ch The System of Rectangular Surveys Ch Monumentation Ch Principles of Resurveys Ch Resurveys and Evidence Ch Resurveys and Restoration Ch. 8 - Resurveys and Water Boundaries Ch. 9 - Special Instructions, Field Notes, and Plats Ch Special Surveys and Mineral Surveys Chapter II – Hopefully teachers of future surveyors will teach the Public Land Survey System (PLSS) Datum to their students. There is a detailed sections reference from the 1973 Manual to 2009 Manual.

What do you mean I am not the Competent Jurisdiction?

Court of Competent Jurisdiction Source of Law
When are the Manual (Federal rules) applicable and when should the Surveyor look elsewhere for the governing (State) rules, i.e., source of law question Chapter I. The General Plan. The Manual. Source of Law, Sections 1-7 (page 3) and 1-7(n) (page 18), and in the water boundary context sections 8-57 through 8-60. Source of law affects boundary line and ownership line location through issues such as intent and unwritten rights. Land description of E1/2 – What is the grantor’s intent? Unwritten rights (a) do not ripen against public domain land and (b) could have ripen prior to acquisition of acquired lands. Sections 1-6, 1-7, & 1-7(n), & 8-57 through 8-60

Land Status Public Domain Land – Federal Rules Acquired Land – Federal or State Rules Non-Federal Land – State Rules Chapter I. The General Plan. The Federal Lands, Definitions, Sections 1-13 (page 4) and 1-13(n) (page 19). Sections 1-13 & 1-13(n)

Owner of land when boundary line is created, i.e., Last Common Grantor Federal – Federal Rules Non-Federal – State Rules Some States have adopted Federal rules for some situations Federal has borrowed State rules for some situations Source of Law Intent Chapter I. The General Plan. The Manual. Source of Law, Sections 1-7 (page 3) and 1-7(n) (page 18), and in the water boundary context sections 8-57 through 8-60. Land description of E1/2 – What is the grantor’s intent? Rule of Last Common Grantor - Within the Public Land Survey System (PLSS) states, every parcel boundary line that can trace its origin to a Federal patent or equivalent must be surveyed by the procedures and principles defined in the Manual. Every parcel of Federal interest lands in all 50 states may be surveyed based on Manual procedures and principles. Every parcel boundary that can trace its origin to a private contract must be surveyed by the procedures and principles defined by State law. Many States have incorporated the Manual by statute, regulation, &/or case law into their boundary location elements of intent, control, and law. The Federal law has borrowed State law for some situations. Sections 1-6, 1-7, & 1-7(n), & 8-57 through 8-60

Measurement Technology Chapter II - Change in Principal
The 2009 edition is largely technology independent. How the surveyor determines the relationship between point A and point B (measurement procedures; what instrumentation and computational techniques is used) will be determined for each survey from the best available technology to meet the purpose of that survey. How to measure is better handled by special instructions. The focus of the Manual is on “how to” determine what is point A and point B, and NOT on how to develop the spatial relationship between point A and point B.

Chapter II Methods of Survey Introduction 2-1.
Surveyor to consult previous Manuals, textbooks, and references for past and present measurement technology and techniques PLSS is orthogonal, with reference to an ellipsoid surface Orthogonal - Lying or intersecting at right angles. Some concepts deleted that were in the 1973 edition includes: sections 2-8 to 2-16 are (remember these sections all fall under the heading of Photogrammetry): 1) section 11 - classification and standards of accuracy of geodetic control surveys in OMB Circular A-16 (subsequently revised, see 2002 edition); 2) section North American Datum of 1927; 3) sec. 11 – mean sea level; 4) section 11 – horizontal control by NGS; 5) section 11 – vertical control by NGS; 6) section 14 – protraction diagrams; and 7) numerous enunciations on accuracy. Some concepts deleted that were in the 1973 edition includes: sections 2-20 to 2-52 are: 1) section 21 – Geographic Position; 2) section 21 - showing latitude and longitude on the plat; 3) section 22 – precision of observations; 4) section 23 – Astronomy in the Manual; 5) pole-zenith-sun triangle; 6) Time; 7) determining azimuth; 8) determining latitude; and 9) numerous enunciations on accuracy. Some concepts deleted that were in the 1973 edition includes: sections 2-53 to 2-73 are: 1) sections 56, 66 & 68 - observations attainable accuracy of the one-minute transit; 2) section 66 – solar transit; and 3) numerous enunciations on accuracy. A concept deleted that was in the 1973 edition section 2-74, paragraphs one through three is “station error.” Some concepts deleted that were in the 1973 edition includes: section 2-74 paragraphs 4 through 7 are: (1) cumulative error, and (2) distribution of station and cumulative errors, and section 2-75 last paragraph and sections 2-76 to 2-78 are: (3) methods of establishing true parallel of latitude, (4) 20 to 40 chains distant, line of sight does not appreciably differ from true parallel, (5) "straight line" defined as a tangent line, and (6) "straight line" defined as a secant line. Some concepts deleted that were in the 1973 edition includes: section 2-79, paragraphs 3 to end and section 2-80, paragraphs 1 through 3 are: 1) an example of computation of convergency, 2) reference to linear amounts of convergency in Field Tables, 3) angle of convergency and linear convergency, and 4) correction in the bearing of meridional section lines to compensate for convergency. A concept deleted that was in the 1973 edition, section 2-81 is geodetic computations by use of the Standard Field Tables.

Specimen Plat – Appendix I – Original Survey
Specimen Plat – Appendix I – Original Survey. Back Cover. Basis of bearings? Bearings reported? Meridian lines vs. lines of constant bearing? Distances? Specimen Plat – Appendix I – Original Survey

Chapter II Methods of Survey Measurement Basis of Distance 2-2.
Horizontal measurement Mean ground elevation For the line above sea level Exceptions to be documented Exceptions to be documented.

Chapter II Methods of Survey Measurement Basis of Direction 2-3.
Reference to the true meridian Defined by the axis of the earth’s rotation True meridian = line along a meridian of longitude Geodetic meridian = Astronomic meridian ± deflection of the vertical Exceptions to be documented. Section 2-27 and deflecton of the vertical. As measurement techniques have evolved and earth centered geodetic datums have come into use, this difference is now readily available, whereas in the past it was difficult to obtain. The historical practice of using an astronomic meridian versus the current capability to obtain a geodetic value can create a potential ambiguity that must be resolved in certain cases. Starting with the 1919 Advance Sheets, the terminology, “as defined by the axis of the earth’s rotation” is contained in the description of the basis of direction for lines of the PLSS. Yet, each subsequent Manual has described astronomical methods for the actual performance of official surveys. A meridian aligned with the “axis of the earth’s rotation” is a geodetic meridian. The meridian of an earth centered reference ellipsoid is aligned with the earth’s axis.

Methods of Measurement
Chapter II Methods of Survey Measurement Methods of Measurement Sections 2-4 through 2-8 2-5. Basis for reporting directions is Bearings = angular measure with reference to the true meridian in degrees, minutes, and seconds Basis for reporting bearings is mean bearing referenced to the true meridian at the point of record Exceptions to be documented. Question: Section 2-4, 2nd paragraph, last sentence – Says that identifiable lines between monuments can be used for the basis of bearings? Other valid methods for determining direction of lines include identifiable lines between monument of adjoining official surveys. “Direction of lines” = “basis of bearings.”

Chapter II Methods of Survey Measurement Methods of Measurement 2-5 & 2-6. Basis for reporting distances is Horizontal measure in chains U.S. Survey Foot At actual ground elevation Horizontal – mean ground elevation – of line above sea level Exceptions to be documented.

Chapter II Methods of Survey Measurement Methods of Measurement 2-7. The Alaska exception Distances reported at zero elevation (sea level) Exceptions to be documented.

Chapter II Methods of Survey Measurement Methods of Measurement 2-8. Direct vs. indirect methods of survey measurement Direct - Measured data gathered and reported in proper basis Indirect - Measured data not gathered in proper basis Direct method of measurement – Solar compass and chain, i.e., true meridian determined at each setup and distance at mean elevation of each line. Indirect method of measurement – Vectors defined by a specific coordinate system and horizontal and vertical datum. It is important that the surveyor understand the difference and know how to derive and properly report measured data for inclusion in official records.

The Geodesy of Large-Scale Cadastral Surveys
Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Public Land Survey System Datum 2-9. The reference system by which measurements of the PLSS are reported

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Public Land Survey System Datum 2-10. Lines, and most elements of the PLSS, are defined in a geodetic sense Meridional boundaries that converge Latitudinal boundaries, similar to latitudinal arcs Boundaries are lines of constant bearing measured at ground elevation Meridional boundaries = principal meridians guide meridians range lines Meridional boundaries ≠ section lines subdivision of section lines

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Public Land Survey System Datum 2-10. Large-scale = difference between plane and geodetic computation methods is significant Mix of astronomic, geodetic, and plane methods The surveyor is expected to distinguish and discern their effect Questions: Section 2-10, 2nd paragraph, 2nd sentence - Is there a measure for the difference between “large scale” and “small scale”? Is there a point in which plane methods are acceptable? “A large-scale cadastral survey is one in which the distinction between plane and geodetic computational methods is significant, ” “For small-scale surveys, the difference between a geodetic system and a plane system is insignificant.” Section 2-10, 3rd paragraph, 2nd sentence – “Historically, many cadastral surveys are a mix of astronomic, geodetic, and plane methods. Does this mean a mix of methods in a single survey or does it mean entire surveys were done by these different methods? Both. “In a retracement, the surveyor must be able to distinguish between the methods used and discern their effect upon the reestablishment of the lines and corners of the prior survey.” Significant or insignificant?

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys True Meridian at the Point of Record 2-11. Basis for reporting direction = true mean bearing Stated in terms of angular measure referred to true meridian north

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys True Meridian at the Point of Record 2-11. Referenced to the true meridian at the point of record Point of record = meridian at the midpoint of the line of sight between the end points

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys True Meridian at the Point of Record 2-12. Forward bearing Back bearing Mean bearing

The Geodesy of Large-Scale Cadastral Surveys Line of Constant Bearing
Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Line of Constant Bearing 2-13. Straight line = line of constant bearing Straight line ≠ line of sight or a geodesic Line of constant bearing crosses each meridian at the same angle A line of constant bearing is a curved line with reference to a plane surface and a straight line with reference to a referenced ellipsoid surface.

Figure 2-1. Lines of exaggerated converging meridians.
Figure 2-1. Lines on exaggerated converging meridians. Page 29. A line of constant bearing is a curved line with reference to a plane surface and a straight line with reference to a referenced ellipsoid surface. Per The System of Rectangular Surveys: General Scheme (chapter III): N-S township lines are meridians, per figure 2-1. N-S section lines are not meridians. N-S subdivision of section lines are not meridians. Figure 2-1. Lines of exaggerated converging meridians.

Does section 25 close?

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Line of Constant Bearing 2-13. Examples of lines of constant bearing Parallel of latitude Rhumb line Small circles Loxodromes Question: Section 2-13, 2nd paragraph, 1st and 2nd sentence – This says “most lines” will cross the meridian at the same angle. This is not so. These crossings vary from 90° in a range from 24” to 14’15” on the interior section lines? Sections lines and subdivision of section lines are typically not meridians.

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Line of Constant Bearing 2-14. 2 points 20 chains apart on parallel of latitude defines the direction of the curve at either point Question: Section 2-14, 1st paragraph, last sentence and 2nd paragraph, 1st sentence – If subdivision of section lines are supposed to be curved, i.e., a line of constant bearing, and not straight, i.e., a line of sight, does that rule apply when calculating lines less than 20 chains in length? The “rule” (subdivision of section lines as lines of constant bearing) is applicable for the reporting of the bearing(s) returned in the official survey record. The same “rule” may or may not be applicable for monumentation (dependent on the measurement method) depending on whether the difference in positions is “significant” or “insignificant.” See section 2-10, 2nd paragraph, last sentence and 3rd paragraph, 1st sentence. In most cadastral surveys the difference in positions is insignificant.

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Line of Sight 2-15. Shortest distance between 2 points Line of constantly changing bearing A great circle Passes each meridian at a different angle What are the characteristics of a straight line (line of sight) under law (43 U.S.C. 752, section 2)? Is this a line of constantly changing bearing (line of sight) (a chord) (a great circle of the earth) or a line of constant bearing (a rhumb line)? When 43 U.S.C. 751, 752 and 753 are read as a whole, it appears all lines are to be north and south lines run according to the true meridian and east and west lines are described as crossing the north and south lines at right angles. To contain all these characteristics the east and west lines must be lines of constant bearing. Whether subdivision of section lines which have not been actually run and marked is a line of constantly changing bearing or a line of constant bearing seems to be clarified in the last sentence of 43 U.S.C. 752, section 2. This addresses running east and west lines in a fractional township but has long been accepted as also pertaining to fractional sections. It is clear the east and west lines being contemplated are lines of constant bearing. The 1973 Manual in section 3-87 uses the term “run straight line” and section 3-88 discussing the same types of lines uses the terms running east or west, per the noted last sentence of section 2. The “straight line” term was enacted in This was a time when most of the work was in Ohio, Mississippi, Indiana, Illinois, Alabama and Louisiana, territories noted for vegetation and rolling ground. In 1805 the basis of bearings, Polaris observations, and the methods and instrumentation resulted in lines run on constant bearing, i.e., "true" "due". The notion that Congress intended "straight line" to be a line of sight line seems to have developed subsequently. It seems clear Jared Mansfield, Surveyor General in 1804 when describing the division of 4 section blocks, to Albert Gallatin, Secretary of Treasury, (the two individuals probably most responsible for the language in the Act of February 11, 1805; 43 U.S.C. 752) described running and monumenting east and west lines of constant bearing, not lines of constantly changing bearing, see Case 1 in Mansfield's Instructions. Of course, in most cases the difference between the positions of the two lines is insignificant. It is anticipated this policy, explicitly stated in the Manual, will be prospective in application and not be retrospective.

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Line of Sight 2-15. Is not a straight line Mean bearing is bearing at midpoint

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Line of Sight 2-16. Some boundaries are defined as line of sight For example, the California and Mexico boundary and the diagonal boundary between California and Nevada. Question: Sections 2-15 and What is the difference between a line of sight and a straight line? Within the PLSS Datum a “line of sight” is a line of constantly changing bearing and a “straight line” is a line of constant bearing, i.e., a line that crosses each meridian at the same angle. See section 2-13, 2nd paragraph, last sentence. The Manual has used the term “straight line” to mean different things. For example, see the 1973 edition, section 2-77, 1st paragraph, 2nd sentence, describing the line tangent to the parallel of latitude as “a straight line.” Also, in the same edition, section 2-78, 2nd paragraph, 2nd sentence. Were north-south section lines “intended” to be lines of sight? Typically, section lines are lines of constant bearing. See section 2-14, 1st paragraph, last sentence.

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Curvature 2-17 & 2-18. Increment/amount/degree of curvature = Angular difference in the direction of the true meridians through each end point. Expressed in minutes/seconds Figure 2-1. Lines on exaggerated converging meridians.

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Curvature 2-17 & 2-18. Correction or adjustment for curvature = Distance, along a meridian, between points on lines with the same end points, one on the line of sight and one on the line of constant bearing Expressed in linear distance Figure 2-1. Lines on exaggerated converging meridians. Question: Section 2-18, 4th paragraph - Is this paragraph intended to provide the standard for the concept of “very large” distances between the line of sight and the straight line? No. “Very large” should be viewed in the context of the official survey being surveyed or resurveyed. Would the courts look at it that way? I would hope not. I think the courts and the Interior Board of Land Appeals (IBLA) would decide there is not one “standard” that fits every type of cadastral survey situation.

Offset from line of sight to line of constant bearing
Standard Field Tables aka Redbook. Table 15 with the Secant line moved north to form a line of sight. If we move the secant line north 5 links as shown in the table the offset at 1 mile will be 5 lks. + 0 lks. = 5 lks., at 2 miles 5 lks. + 3 lks. = 8 lks. offset, and at 3 miles 5 lks. + 4 lks. = 9 lks. offset. At 45 degrees latitude, the offset at the midpoint of a parallel of latitude line 1 mile in length is 0.3 links = 0.2 feet; at 70 degrees, 0.7 links = 0.5 feet. Correction or adjustment for curvature.

The Geodesy of Large-Scale Cadastral Surveys Convergency of Meridians
Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Convergency of Meridians 2-19. Correction for convergency Reference spheroidal / ellipsoidal, e.g. Clarke Spheroid of 1866 The linear amount of the convergency of two meridians is a function of their distance apart, the length of the meridian between two reference parallels, the latitude, and the spheroidal or ellipsoidal form of the earth’s surface. The correction for convergency in any closed figure is proportional to the area and may be computed from an equivalent rectangular area. See errata page.

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Lengths of Arcs of the Earth’s Surface 2-20. Horizontal distance, at Mean elevation above sea level Assume New York City and Paris are on the same parallel of latitude, what is the distance between the two cities? Assume New York City and Paris are on different parallels of latitude, what is the distance between the two cities?

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Geometric Effects and Apparent Misclosure 2-21. Geometric effect = Differences between plane surveying and computations and PLSS datum surveying and computing Apparent Misclosure – If using geodetic (mean bearings) to close a survey, using grid computations, it will appear to not close, because convergence is not accounted for. To properly interpret between plane surveying and computations and surveying, and computing on the PLSS datum. Question: Section 2-21, 1st paragraph, 3rd sentence - I am not sure that the concept that the plane computations “create” the effect of apparent misclosure. I believe that this would give the idea that plane computations should not be used at all. However, those are exactly the computations used when doing proportioning. “ the use of plane survey computations to lay out or evaluate PLSS surveys requires special knowledge of how to properly interpret and apply the results. Section 2-21, 1st paragraph, 2nd sentence. Contrast the “perfect” township, i.e., with meridian lines for the E and W exteriors with the “perfect” section, i.e., with parallel lines for the E and W exteriors.

Figure 2-2. Apparent misclosure due to convergency of the meridians.
Figure 2-2. Apparent misclosure due to convergency of the meridians. Page 32. The township / section of a BLM plat appears to misclose using plane computations, i.e., with plane computations meridians do not converge, whereas with geodetic computations meridians do converge. Figure 2-2. Apparent misclosure due to convergency of the meridians.

Does section 25 close?

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Geometric Effects and Apparent Misclosure 2-22. Geometric effects To and from true meridian To and from mean bearings Between ground horizontal and grid or sea level distances To properly interpret between plane surveying and computations and surveying, and computing on the PLSS datum.

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Geometric Effects and Apparent Misclosure 2-22. Geometric effects Correction between mean, forward and back bearings Elevation of line Misclosure and apparent misclosure To properly interpret between plane surveying and computations and surveying, and computing on the PLSS datum. Question: Section Does the use of plane computations actually create the problems? Or is it they might cause a problem if improperly applied? The latter. “Proper” use of plane computations within the PLSS Datum implies making the necessary conversions between the plane and the geodetic, e.g., those listed here.

The Geodesy of Large-Scale
Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Area 2-23. Computed at mean ground elevation Double meridian distance or equivalent Record data Compass rule adjustment prior to calculations (but not apparent misclosure) See also sections 9-62 through 9-70.

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Area 2-24. Area & geometric effects Grid area ≠ PLSS area Scale factor Elevation factor

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Parallel Lines of the PLSS 2-25. PLSS Parallel lines = 2 lines a constant distance apart To produce as many regular legal subdivisions as possible In the PLSS, parallel lines that are not true east and west will have different bearings. Section 2-25, 1st paragraph – In the Rectangular System does the 640 acre objective trump the concept of true meridians and the requirement that lines inside the township cross at right angles? Yes. “The township shall be subdivided into sections, containing, as nearly as may be, six hundred and forty acres each, by running parallel lines through the same from east to west and from south to north at the distance of one mile from each other, ” 43 U.S.C. 751, clause 3. Which appears to conflict with clause 1 of the same act; “The public lands shall be divided by north and south lines run according to the true meridian, and by others crossing them at right angles, so as to form townships of six miles square, ” Clause 3 is for township subdivisional lines, clause 1 is for township exteriors. See section 1-26.

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Elevation 2-26. Height above or below mean sea level Alaska exception – at sea level Proportionate measurement and significant elevation difference

Chapter II Methods of Survey The Geodesy of Large-Scale Cadastral Surveys Deflection of the Vertical 2-27 & 2-28. Astronomic meridian Geodetic meridian Laplace correction = difference Method clearly stated in the record This difference is referred to as the Laplace correction and is a result of the difference in direction of the local gravity vector, the normal to the geoid, and the normal to the reference ellipsoid. This causal factor is known as the “deflection of the vertical” or “deflection of the plumb.” The accuracies required in some surveys made such corrections consequential. Termed the Laplace correction, this value has rarely been applied in the PLSS, because the precision of historic survey methods and measurements made it inconsequential and impractical to consider. The ability to obtain the correction has advanced considerably in recent years. Modern surveying technology now enables direct determination of the geodetic true meridian. The surveyor must remain cognizant of the effect of the various historical and contemporary methods of observation and computation on resulting determinations of the true meridian. The modern survey record should accurately document the basis of direction of the survey as being geodetic or astronomic depending on the method used for determination. “[A] correction will be applied to the astronomic observation.” This does not read, “applied to the geodetic values to place them on the same basis as the astronomic observations,” because it is the exception to the rule to how survey measurements and calculations are currently conducted. The rule as stated is based upon the premise that calculations are done on the reference ellipsoid, and the returns are geodetic not astronomic. I note that historically the base has been astronomic. I also note in a resurvey mode, the difference between retracing in a geodetic base rather than an astronomic base is insignificant, with rare exceptions. And I note that the surveyor can report to an astronomic base if the resurvey demands it in order to not "impair the bona fide rights or claims."

Coordinate Systems and Projections Geodetic Reference Systems
Chapter II Methods of Survey Coordinate Systems and Projections Geodetic Reference Systems 2-29. National Spatial Reference System (NSRS) The Manual does not specify an ellipsoid, other than note that to be aligned with the axis of the earth’s rotation implies a geodetic meridian referenced to an earth centered ellipsoid. Cadastral surveyors should use automated computational systems as well as geographic and projected grid coordinate systems oriented directly to the NSRS to conduct official surveys.

Coordinate Systems and Projections Latitudes and Departures
Chapter II Methods of Survey Coordinate Systems and Projections Latitudes and Departures 2-30. Latitude = latitudinal difference Departure = longitudinal difference When a line is reduced to its cardinal equivalents. See section 7-7. Question: Section 2-30, 1st paragraph, 1st sentence - “Prior to automated computations.” Does this statement indicate that the BLM changed methods because of computers? No. It was the PLSS Datum before and it is the PLSS Datum after. The tools to measure and compute changed, the Methods of Survey have not. Section 2-30, 1st paragraph, 1st sentence - When did the “automated computations” come into play and what aspects of the calculations did they affect? There are two parts to this (1) data gathering methods, e.g., direct measurement tools such as solar compass, chain, and indirect measurement tools such as transit, EDM, and GPS, and (2) data computational methods, e.g., standard field tables, calculators, computers. See section 2-8 3rd and 4th paragraph for further description. Section 2-30, 1st paragraph, 1st sentence - Does “rectangular coordinate system” mean the same thing to a BLM surveyor as it does to a private surveyor? Per the Manual the term “rectangular coordinate system” means the PLSS Datum, a geodetic system.

Figure 2-3. Curvature of lines of a large triangle.
Figure 2-3. Curvature of lines of a large triangle. Page 34. Figure is about 2½ miles N-S and 2 miles E-W. Shows forward – mean – back bearings. Would the coordinates computed using the first forward bearing and subsequent interior angles for bearings be identical with the coordinates computed using mean bearings? Figure 2-3. Curvature of lines of a large triangle.

A tangent to the parallel.
Figure 13. A tangent to the parallel. Page 54 Manual 1973 edition. A tangent to the parallel.

A secant of the parallel.
Figure 14. A secant of the parallel. Page 55 Manual 1973 edition. A secant of the parallel.

Coordinate Systems and Projections
Chapter II Methods of Survey Coordinate Systems and Projections Geographic Positions 2-31 & 2-32. Two corners tied to NSRS Coordinate data to be replicated with known uncertainty Used on Plats – State Epoch, Datum, Field Observations, and Computational Techniques The field observations, techniques, and computational processes will be documented in such a manner that future surveyors can confidently replicate the position of the points of the survey on the face of the earth within a known mathematical uncertainty. For future PLSS surveys, geodetic positions will be used wherever possible, and the exception will be noted. The numbering of parallel of latitudes always begins with zero at the equator. The numbering of the meridians (longitude) will increase from zero to the west or east of the Greenwich Meridian (the Airy line, established in 1851 and officially adopted by the U.S. in 1884; geodetic value not astronomic) which is the meridian passing through the centre of the transit (Airy's) instrument at the Observatory of Greenwich, England. The source of the latitude and longitude values, and a date, should always be clearly stated. The Bradley Greenwich Meridian (established in the mid 18th century) is 5.79 meters west of Airy's Greenwich Meridian. The London Meridian is 0° 05′ ″ W. (4.17 miles from Greenwich Meridian). The Washington Meridian passes through the center of the dome of the old Naval Observatory at 24th Street and Constitution Avenue, N.W., Washington, D.C. It was provided for by the Act of September 28, 1850 (9 stat. 513, 515). This act was repealed by the Act of August 22, 1912 (37 stat. 328, 342). The Washington Meridian (all geodetic values) is: 77° 03′ ″ W. NAD 83(1993), 77° 03′ ″ W. NAD 83(1986), 77° 03′ ″ W. NAD 27, 77° 03′ ″ W. USSD/NAD (U.S. Standard Datum , North American Datum ), 77° 02′ ″ W. BESSEL (Datum did not have a name, this refers to the ellipsoid used, ). The astronomic value at the Washington Meridian is smaller by 3.8 seconds, a difference of about 300 feet. The International Reference Meridian (IRM) is tied to the definition of time and is meters (1999) east of the Greenwich (Airy) Meridian. In 1880 U.S. Coast and Geodetic Survey officially adopted the use of the Clarke 1866 ellipsoid for all future positions, however this was implemented just in the northeast U.S. under a datum referred to as the New England Datum. The change from BESSEL came about with the completion of the Transcontinental Arc of Triangulation in 1898 and the subsequent publication of a national datum called the U.S. Standard Datum in 1901.

Chapter II Methods of Survey Coordinate Systems and Projections Grid Coordinate Systems and Coordinates 2-33 & 2-34. Differences between SPCS and PLSS Sea level factors Elevation factors Grid scale factors Mapping angle Acreage Changed verbiage to “State Plane Coordinate System” to reflect current terminology. Also added “and to allow for engineering computations in an orthogonal model” to indicate the primary purpose of the system and its reason for existence. Before a measured distance (ground distance) can be reduced to a grid distance, it must first be reduced to a geodetic (distance along the ellipsoid) distance. Classically, a ground distance has been reduced to either the geoid distance (distance along the geoid, aka. the sea level distance) (historically designed as the sea level factor) or the ellipsoid (geodetic distance) (recently designed as the elevation factor). Thus the geoid height (sea level/ellipsoid separation) must be considered. In the conterminous U.S. and in Alaska this is a systematic error (opposite sign for each). A geoid height of −30 meters systematically affects all reduced distances by −4.8 ppm (1:208,000).

Double Proportionate Measurement Sections 7-8 & 7-9
Better definition/example of the double proportion measurement. Discussion of cardinal equivalents. Resurveys and Restoration Primary Methods Double Proportionate Measurement, section 7-8 (page 166). Cardinal Equivalent, section 7-9 (page 166).

Figure 7-2 (page 167). Double proportionate measurement and cardinal equivalents.
Errata (10/27/10). Section 7-10, Figure 7-2, Page 167 Under the "True line solution", the bearing from "X" to "C" should be S. 89° 59' 09" W., not N. 89° 59' 09" W., and in the "True Line" table, for Course X-C, the "Lat." column, should read S , not N See errata figure 7-2.

Chapter II Methods of Survey Coordinate Systems and Projections Grid Coordinate Systems and Coordinates 2-34. Repeatable coordinates Quantifiable accuracy standard May be collateral evidence May be best available evidence May be substantial evidence

Coordinates as Collateral Evidence
Repeatable coordinates may be the best available evidence for the position of an obliterated corner. “ if the first surveyor documents how he or she obtained the coordinates so the second surveyor can, within an acceptable degree of confidence, determine the same point on the earth's surface (following in the computational footsteps) within an acceptable level of certainty, then coordinates may be the best available evidence of the corner position.” Advancement in Technology, enabling quick generation of precise and repeatable coordinates, has resulted in corner positions being “witnessed” by coordinates. Section 2-34. Presumably any point can be reestablished once its coordinates have been determined. However, great care must be exercised to ensure that the original coordinate pairs were produced by a process that is repeatable within a quantifiable accuracy standard. Repeatable coordinates may provide collateral evidence of a corner position; may constitute the best available evidence of a corner position; and in some cases, may constitute substantial evidence of the position of an obliterated corner. Gives guidance on how (a) to evaluate extant coordinates and (b) how to leave a record for coordinates. Following in the computational footsteps. Obliterated corner or a lost corner? Obliterated corner not a lost corner. Sections 2-32 & 2-34

Coordinate Systems and Projections Use of Local Survey Measurements
Chapter II Methods of Survey Coordinate Systems and Projections Use of Local Survey Measurements 2-35 & 2-36. Basis of Bearings Coordinate basis Question: Section If the use of local surveys can be a problem due to the basis of bearings, what does the BLM surveyor do to “properly” incorporate these records into the PLSS system? Attempt to make the proper conversions of the local survey data from the local datum to the PLSS Datum.

Coordinate Systems and Projections Accuracy of Survey Measurements
Chapter II Methods of Survey Coordinate Systems and Projections Accuracy of Survey Measurements 2-37. If different from the Manual is stated in the special instructions Expected that accuracy is consistent with instrument specifications

Chapter II Methods of Survey Coordinate Systems and Projections National Spatial Data Infrastructure 2-38. Geospatial data Cadastral data Federal Geographic Data Committee Cadastral Data Content Standards Front plate of Manual: The information contained within the Manual of Surveying Instructions assures consistency with the Cadastral Data Content Standard developed by the Federal Geographic Data Committee’s Subcommittee on Cadastral Data in support of the requirements of the Office of Management and Budget Circular No. A-16, revised, entitled Coordination of Geographic Information and Related Spatial Data Activities.

Coordinate Systems and Projections Statistical Analysis of Survey Data
Chapter II Methods of Survey Coordinate Systems and Projections Statistical Analysis of Survey Data 2-39. Special instructions to define Methods Expectation of accuracy

Coordinate Systems and Projections Computations in the PLSS Datum
Chapter II Methods of Survey Coordinate Systems and Projections Computations in the PLSS Datum 2-40. Summary of these issues Line of constant bearing True mean bearing Proper use of grid projections Converting geodetic or grid data to PLSS datum Examples of computations affected by the geometric and geodetic effects of the PLSS datum include: Computing a line of constant bearing Understanding true mean bearing computation Understanding and applying grid coordinate projections, e.g., state plane coordinates Methods for conversion of geodetic or grid data to PLSS Datum Specialized computations in the PLSS datum, e.g., lost corner computations Account for elevation, elevation variation, and scale factor Area computation

Coordinate Systems and Projections Computations in the PLSS Datum
Chapter II Methods of Survey Coordinate Systems and Projections Computations in the PLSS Datum 2-40. Summary of these issues Specialized computations Elevation, elevation variation, scale factor Area Examples of computations affected by the geometric and geodetic effects of the PLSS datum include: Computing a line of constant bearing Understanding true mean bearing computation Understanding and applying grid coordinate projections, e.g., state plane coordinates Methods for conversion of geodetic or grid data to PLSS Datum Specialized computations in the PLSS datum, e.g., lost corner computations Account for elevation, elevation variation, and scale factor Area computation

Chapter II Methods of Survey Coordinate Systems and Projections Units of Direction 2-41. Bearings Reported consistent with specials accuracy requirements Minutes; minutes & portions thereof; minutes & seconds

Chapter II Methods of Survey Coordinate Systems and Projections Units of Distance 2-42. By law, chain is unit of linear measure Other units will be specified in specials

Chapter II Methods of Survey Coordinate Systems and Projections Units of Distance 2-43. Chain unit defined by U.S. Survey Foot French, Spanish, & Mexican units See tables 2-1, 2-2, and 2-3.

Know where you are working
Research-Research-Research

Know how to resurvey these “Special Surveys”

SUMMARY By fundamental law, upon the issuance of a patent for land by the Federal government; it is just as if the monuments, survey plat and field notes, and the laws, regulations and rules governing how to survey the land described in the patent, are stapled to the face of the patent. SUMMARY By fundamental law, upon the issuance of a patent for land by the Federal government; it is just as if the monuments, survey plat and field notes, the laws, regulations, and rules governing how to survey the land described in the patent, are stapled to the face of the patent. Cragin v. Powell, 128 U.S. 691 (1888). The survey rules are spelled out in the manuals, circulars, instructions and regulations issued by the General Land Office and its successor the Bureau of Land Management. If later a boundary location becomes unclear the Manual is the guidance (the rules) governing the relocation of the corners and boundaries in conformance to the controlling monuments, survey plat(s), field notes, policies, regulations, and laws. The Manual is the guidance (the rules) governing the subdivision of sections, in conformance to the controlling monuments, survey plat(s), field notes, policies, regulations, and laws. The survey rules are spelled out in the manuals, circulars, instructions and regulations issued by the GLO and later by the BLM.

Errata

Resources BLM Survey Manual Website
Public Land Survey System Foundation Survey Manual Website Survey and Patent Records Website Move into the resources available to keep track of the Manual and related information. Move through classroom exercise, student expectations, and questions.

Certified Federal Surveyor (CFedS) Website
Federal Jobs Website Move into the resources available to keep track of the Manual and related information. Move through classroom exercise, student expectations, and questions.

The Manual of Surveying Instructions, the PLSS Datum, and the Local Surveyor

Similar presentations

Presentation on theme: "The Manual of Surveying Instructions, the PLSS Datum, and the Local Surveyor"— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

The Manual of Surveying Instructions, the PLSS Datum, and the Local Surveyor

Similar presentations

Presentation on theme: "The Manual of Surveying Instructions, the PLSS Datum, and the Local Surveyor"— Presentation transcript:

Similar presentations

About project

Feedback