c NOAA Technical Memorandum NOS NGS-5 x*F °>* ^TES O* * NATIONAL GEODETIC SURVEY DATA: AVAILABILITY, EXPLANATION, AND APPLICATION National Geodetic Survey Rockville, Md. June 1976 [^f^OO NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION / National Ocean Survey NOAA TECHNICAL MEMORANDUMS National Ocean Survey — National Geodetic Survey Subseries The National Geodetic Survey (NGS) of the National Ocean Survey establishes and maintains the basic National horizontal and vertical networks of geodetic control and provides government -wide leadership in the improvement of geodetic surveying methods and instrumentation, coordinates operations to assure network development, and provides specifications and criteria for survey operations by Federal, State, and other agencies. The NGS engages in research and development for the improvement of knowledge of the figure of the Earth and its gravity field, and has the responsibility to procure geodetic data from all sources, to process these data, and to make them generally available to users through a central data base. NOAA Technical Memorandums of the NOS NGS subseries facilitate rapid distribution of material that may be published formally elsewhere at a later date. Copies of memorandums listed below are available from the National Technical Information Service, U.S. Department of Commerce, Sills Building, 5285 Port Royal Road, Springfield, Va. 22151. Prices on request. NOAA Technical Memorandums NOS NGS-1 Use of climatological and meteorological data in the planning and execution of National Geodetic Survey field operations. Robert J. Leffler, December 1975, 30 pp. NOS NGS-2 Final report on responses to geodetic data questionnaire. John F. Spencer, Jr., March 1976, 39 pp. NOS NGS-3 Adjustment of Geodetic Field Data Using a Sequential Method. Marvin C. Whiting and Allen J. Pope, March 1976, 11 pp. NOS NGS-4 Reducing the Profile of Sparse Symmetric Matrices. Richard A. Snay, June 1976. NOAA Technical Memorandum NOS NGS-5 NATIONAL GEODETIC SURVEY DATA: AVAILABILITY, EXPLANATION, AND APPLICATION Joseph F. Dracup National Geodetic Survey Rockville, Md. June 1976 : s o o Q. ID Q UNITED STATES DEPARTMENT OF COMMERCE Elliot I. Richardson, Secretory NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION Robert M. White, Administrator National Ocean Survey Allen L. Powell Director VeTc*^ lO Q to CONTENTS Abstract 1 Introduction 1 Availability and explanation 2 Publications 2 Horizontal control data 5 Physical geodesy data 21 Vertical control data 23 Accuracy of horizontal control stations 29 Application 31 Bibliography t 34 Digitized by the Internet Archive in 2012 with funding from LYRASIS Members and Sloan Foundation http://archive.org/details/nationalgeodetiOOdrac NATIONAL GEODETIC SURVEY DATA: AVAILABILITY, EXPLANATION, AND APPLICATION Joseph F. Dracup Chief, Horizontal Network Branch National Geodetic Survey National Ocean Survey, NOAA, Rockville, MD ABSTRACT. Geodetic data have been issued by the National Ocean Survey and its predecessors for more than 100 years. During this period, the data were furnished in a variety of formats, finally evolving into the present-day tabulations. Although much of the data is available in a modern standardized form, some material is still published on old-style listings. Explanations are given to assure that the user fully understands the published information. Some of the data was computed on several reference surfaces, which must be considered when the information is used to relate maps and charts of the past with the present. Explanations are provided in regard to survey accuracies and problems inherent to certain geometric configurations. Since hundreds of publications and thousands of papers dealing with geodetic surveys have been published or presented, the compilation of a complete bibliography would be a formidable task. This report gives a concise listing of publications and papers of general interest and their sources of availability. Also included are detailed references to the application of geodetic control and practices, as only a brief discussion of this subject is presented in the text. INTRODUCTION For more than 150 years, the Coast and Geodetic Survey (C&GS) collected and published data related to the oceans and the land. With the formation of the National Oceanic and Atmospheric Administration (NOAA) . in October 1970, the Coast and Geodetic Survey became a major line component of this agency and was renamed the National Ocean Survey (NOS) . This reorganization later included the transfer of the seismological and geomagnetic activities from NOS to the Environmental Research Laboratories (ERL) , another mainline component of NOAA which is located in Boulder, Colorado, and the establishment within NOS of the Office of the National Geodetic Survey (NGS) , the latter to include all geodetic functions of the former C&GS. In 1973, the seismological and geomagnetic functions were transferred to the U. S. Geological Survey (USGS) . However, the national data bank for geomagnetic data remained with NOAA and geomagnetic information is available from the National Geophysical and Solar-Terrestrial Data Center, EDS/NOAA, Boulder, Colorado 80302. The crustal movement studies which are performed by NGS will continue to be published and distributed by that office. Results of these studies and requests for geodetic data may be obtained from the Director, National Geodetic Survey Information Center, C18, Rockville, Maryland 20852. These organizational changes should have little effect on most users of geodetic control, since these data will continue to be published and issued by the NGS. However, those surveyors and engineers who require information relating to seismic and magnetic data should refer their requests to the organizational components noted in the previous paragraph. NGS will provide, upon request, price lists for the geodetic data. Also available is an information bulletin listing specific publications of this office, in addition to those mentioned in this Technical Memorandum. The primary content of the information bulletin is directed to servicing procedures. AVAILABILITY AND EXPLANATION Publications Some bound publications of NGS and NOS are printed and sold by the Superintendent of Documents, U. S. Government Printing Office, Requests should be directed to that agency and not to the NGS. If, however, a publication cannot be furnished by the GPO, it occasionally may be obtained from NGS stock. The Department of Commerce also maintains field offices in most major cities. These offices are usually able to fill requests promptly. During its long history, the Coast and Geodetic Survey prepared more than 300 Special Publications dealing with all of the scientific disciplines in which the organization was involved. Many of the older publications are out of print. Most will not be reprinted because they are of little present- day interest, and their contents have been superseded by later publications. NGS has retained file copies of those documents concerned with geodetic surveying and generally can furnish commercial-type copies of excerpts or occasionally even an entire publication. The NGS , as in the past, will furnish data and their personnel are always available for advice concerning technical matters, such as specifications, use of theodolites and electronic distancing equipment, computations, and review of unsatisfactory closures between points established by this agency. Also available from NGS are numerous papers, technical bulletins, data reports, and similar pamphlet-type publications which have been prepared and issued over the years. Generally such material is limited in depth and scope but often appears in lists of references. For this reason, NGS has maintained a supply of the more popular ones and will reproduce a few copies of others upon request. The reference library of any surveyor or engineer who performs control surveys or employs the State Coordinate Systems should contain the following NGS and ACSM publications and papers. All are included in the more comprehensive bibliography cited at the end of this paper; hence, only a brief identification is given below. (1) Coast and Geodetic Survey, : Plane Coordinate Projection Tables, Special Publication series. For states where projects will be undertaken. (2) Coast and Geodetic Survey, 1949, reprinted 1971: Sines 3 Cosines 3 and Tangents 3 ten decimal places with ten-second interval 3 0°-6° i Special Publication No. 246. For plane coordinate computations on Lambert projection. (3) Mitchell, H. C, and Simmons, L. G. , 1945, revised 1974, reprinted 1975: The State Coordinate Systems (A Manual for Surveyors) 3 Special Publication No. 2S5 (4) Dracup, J. F., and Kelley, C. F., 1973, reprinted 1975: Horizontal Control as Applied to Local Surveying Needs. (5) Simmons, L. G., 1968, reprinted 1975: Geodetic and Grid Angles - State Coordinate, Systems, ESSA Technical Report C&GS 36. (6) Federal Geodetic Control Committee, 1974, reprinted 1975/1976: Classification 3 Standards of Accuracy 3 and General Specifications of Geodetic Control Surveys . (7) Federal Geodetic Control Committee, 1975/1976: Specifications to Support Classification, Standards of Accuracy 3 and General Specifications of Geodetic Control Surveys . (8) Dracup, J. F. , 1969, revised 1973: Suggested Specifications for Local Horizontal Control Survey s } Technical Monograph No. CS-1. (9) Dracup, J. F., 1970: Standards and specifications for supplemental horizontal control surveys. (10) Mitchell, H. C, 1948, reprinted 1974/1976: Definitions of Terms Used in Geodetic and Other Surveys^ Special Publication No. 242. (11) Tomlinson, R. W. , and Burger, T. C. , 1971, revised 1975: Electronic Distance Measuring Instruments , Technical Monograph No. CS-2. The impression from a cursory review of the reference material is that the use of the State Plane Coordinate System involves very complex procedures. Such is not really the case. In the final analysis, State plane coordinates are really nothing more than an adaptation of the latitude and departure practices which have been in use for centuries. Numerous reasons have been given during the last 4 years for not employing the State plane coordinate systems. Some are quite valid, e.g., a lack of national network control; but others, especially those related to scale factors, are irrelevant. The application of a scale factor is arithmetical, not an involved mathematical procedure. In those higher elevation sections of the country, the reasons given for not using the system include the reduction to sea level in addition to scale factors. The sea level reduction is also arithmetical. In fact, the two factors can often be combined, thus resulting in a single computation to reduce each measured distance. Some surveyors and engineers contend the State systems are not adaptable to their projects because ground distances are required in laying out structures, etc. This problem, of course, can be generally overcome by projecting the State plane coordinates to the average elevation and correcting for the average scale factor of the site. In a few projects examined by the author, this has been a needless exercise since the distance measurements made at the site for construction purposes either involved such short lengths or such inaccurate taping procedures that the requirement for project coordinates was seldom justified. Horizontal Control Data Early in the 1930' s, it was decided to lithoprint horizontal and vertical control data in a loose-leaf form rather than in bound volumes by States as previously. For this format (which became known as the "lithos"), separate listings for the geographic positions, plane coordinates by zones, and descrip- tions were required to complete the data for horizontal control points. Leveling data were issued by lines, and material involving several lines was often required to furnish the complete data for an area. As time passed and a tremendous amount of data was accumulated, it became obvious that this format was cumbersome and that a new approach to publishing the material was mandatory. It was then decided to issue the data in 30' by 30' quads, the advantages being that all data for a horizontal control point could be printed on a single sheet of paper and all the leveling control for an area of about 800 square miles could be assembled in a single volume. At present, previously published adjusted geodetic data for most States have been converted to the quad format. With rare exceptions, all new adjusted data are being prepared in this form. The New Adjustment of the North American Datum now underway is scheduled for completion in 1983. Published data for this adjustment will be computer generated, probably in a format similar to the quad format. The diagrams for the quad format are on a 1:250,000 scale, and show horizontal and vertical control established by NGS , USGS , and any other Federal, State, or local Government agencies whose data have been accepted for publication by NGS. The acceptance or adjustment of data published by NGS is made with the understanding that prescribed specifications for the stated standard of accuracy have been rigorously followed by the establishing agencies; the NGS accepts no responsibility for the accuracy of such surveys. Diagrams NGS will continue to publish the State diagrams showing control established or adjusted by NGS, one for the horizontal control and another for the vertical control (fig. 1 and 2). In areas where the control is congested, larger-scale diagrams, such as nautical base charts, supplement the State diagrams. The normal dimensions of the quad-format diagrams are 1° in latitude by 2° in longitude with the data assembled in 30' i! l! t i ) i! J!)! jijj (i H i! Figure 1.- -State diagram showing horizontal control established by or accepted for adjustment by NGS . |) jj j; ji robm j, Figure 2. —State diagram showing vertical control established by or accepted for adjustment by NGS . by 30' volumes. The horizontal and vertical control data are issued separately and designated as shown below: 26 25 081 4 25 081 1 DIAGRAM NG 25 080 4 -17-8 MIAMI 25 081 3 25 081 2 25 080 1 25 080 3 25 080 2 25' 82' 81' 80' Each station is assigned a number identified as "QSN" (Quad Station Number) . These numbers are assigned to stations in a new project and tabulated in alphabetical sequence, generally in two groupings, the marked stations in one group, and intersection points in the other. When the horizontal control data for an entire state are converted to the quad format, the stations are normally tabulated in alphabetical sequence and in two groupings, but not by project. There are variations to these practices due to certain situations, such as clustering all intersection points in a general location, to save paper, or to satisfy some particular condition. All QSN ' s begin with 1001, thus each station has a unique 10 digit identifier. In some of the earlier listings, nearby marks connected by traverse or replacement stations were assigned the same number as the station. Later, in many cases, a letter was added. For example: 250802 station 1029A could be the point connected by traverse and 1029B the replacement station for 250802 station 1029. For inclusion in the planned data bank, stations containing a letter will need to be renumbered to avoid the alpha-numeric identification. The data bank, when finally compiled, will contain all the observations, the adjusted results, and descriptions and recovery notes for all horizontal control stations. In a few instances along coastlines, quad dimensions are 2° in latitude by 1° in longitude, and on other occasions, to offset the need of an additional sheet, they are slightly larger than normal size. Larger-scale base maps are also used to supplement the regular quad diagrams in areas where a large concentration of control exists. Control established or adjusted by the NGS is shown in black; that established, computed, and issued by the USGS in red; and data accepted by the NGS for publication in brown. The accuracy of the control is also indicated. A sample regular-size quad sheet (without color coding) is shown in figure 3. Data Sheet Format An example of the new format for horizontal control data sheets is shown in figure 4. This single-sheet type of listing replaces the multi-page tabulations previously employed. In the old "litho" format, separate sheets were necessary for the listings of the various data; for the example shown in figure 4, the user would have received as many as eight sheets of paper. Since much of the horizontal control data for a few States is still issued in the "litho" type format, examples and explanations of the data are given later. The form shown in figure 4 is largely self-explanatory. The following comments should assure a more complete understanding of the tabulated data. (1) Source - Archive number assigned to computations in which position was determined. Other source numbers are occasionally shown on data sheets prepared several years ago. These refer to projects in which the station was used as control, but this practice has been discontinued. (2) Field sketch - A sketch is drawn for each project and filed by State and number. Sketches for projects that extend into more than one State are assigned to one of these States. Usually only the sketch for the project in which the station was originally positioned is shown. The field sketch number and locality are omitted on more recent tabulations. (3) Geodetic positions - Positions given to five decimal places of seconds are for computational purposes only and are not an indication of accuracy. (4) Elevations - Values shown to one decimal in meters and to even feet were probably determined from vertical angles (trigonometric leveling) . Elevations given to two decimals in meters and one decimal in feet were generally determined in the 10 !i!!!!!jhi!ij -l 1 ■ L ^£3 ** ' £ I 9 ■SI; " 3 ik: s 8 ,'} s ! *" gs ! k ii Ph^ in 1 »1— UJ HI . s' s ! > . : - I ; : ' ■ ■ Slli'l IE ■ " 1 -p - 5 or £ < ► ^- CO z 2 on "O z < <^s 0) £ _J "5 5 < <: o X i— fO o z o ►- • CO ® X) O +* f •HBO tc * • O •> f «*h ro-O s 1 ««rt » o <> u. z> o<| h- "<» z zz Ul<< H 0. < < — 1UZZ B o oo in «D fNt O K CD i 4 © o * * ■ (M 0* IliJjQO H*- > 9BO a u ■*-* hoc* c- » • t« e ja • Hon So v\f-o«* • « • 3BH h »t. a i»o • DV4 «\T\« O <3 O <0 • c ■ ■h-i3 «o « *> «. an S 3 o e<-> t, u t, a »o 3 o OW • flfl&fl bocd'a « <-» o * 3 u £ nps Ojq b o o OOHO O rn m I S-o*-« o t o u »-H CO e o q a -w h H * ruon i n O OtH rH H B-H >.d »H*H • i ■ a 3 «**o otMm o «-h 3 • -H+J *> ^oia » ja • • ©d no > n d -h j3 oh * ,o j< I ja +3 *h t. cih m u*i ^ • ■ o ■h* ojdi- £. « < oh a a paps ••••«• i« ill |OMM ■an t e,H *• • 05 O (4 O * P. r> ode HOWB-HdVt-d OH C -r4 O • §H B4>MH A dCCDS 6 d,0 wo d ope H+*-rI-t« J3 5 jQ ■ 5* 1 >o gJ« ft S.t29 ■h b ••o i o a <«i«f op « d H • V(+» ■iHO>^ -• O • • x*. c a J30*-o£ -"'^f^ wo H 8. . a co •H O 4* CO val +»4* 5 9 o oua >>«n» m«C • i * a itn o +» h e CO tHH HH«4> ^•H aj 3 a 3 o q t. U U H I • H -S * H »H'0»rn+»5. a* « bd o o, 3o*s^ojdt seo •>< » (h © to ® +* Si ■f>«Q+>efl-peq+* « • ¥ § do » • b a H Hd ^Of«* '• N e ft ^^ B"P CQH4* -*Ih4» mH a|3a^ v a w ass^§s£ N .3 • • H S *H «o*h o • CD *4 e HO dir\ ir\ ^ 4» ^ • 4»«H • o MHH H OV0 «H +» ja e J3 9 QrH lj %-t o of e m a 1 * !iE Si \ 5 T3 V. j: o *^ si I •«S >- I ft 8 '. \ moo aio> o • • • y * 1. : 0^ + ^ 1 x O ^J- OJ OJ V u 63 2 a - fe CJVQO^ f 5 . 8GZS i i HC\J o * « * * K tfNOJffMNJ s | Z ! OMT* ^-*45 ^ * * * « 3 s ' r '© O^ o *-r4<^ri E e H^O^O Mhhoj ir It ! KEg g a So i \ ■I ]l J 1 i o J 1 \ S 5 IT* m s a " H s i g 3 S 9 •i H 4» J* o ♦ WrfH s 9939 ;s 13, CO U >i 4-1 CO d) p tr a) c o o CD •H > +J T3 u -p c o u +J c o N -H o M-i o +J a> cu CD rH a, g nj CO I I u o CT> -H fa 12 course of a leveling project or from a spur line run by the horizontal control party from nearby bench marks. Elevations determined in such spur leveling usually carry the notation "WYE LEVELING." Those with no check are so indicated, and the source of the data, if other than the NGS , is also noted. Because of policy changes, remarks concerning the elevations are not always shown on the latest listings. A few words of caution with respect to these values. Vertical angle elevations can be ± 3 feet or more in error relative to leveling control in the general area, and many elevations shown to two decimals in meters are unadjusted values. These data are tabulated for use in reducing electronic distance measurements and to furnish elevation control for projects where accuracy is not critical. Whenever a project requires accurate elevations, the State or quad diagrams should be examined to ascertain the availability of leveling control in the immediate area; then a request should be made to the appropriate agency for the data. (5) State coordinates - The "X" coordinate is the value in feet referenced east or west of a meridian selected, and designated as the central meridian for a particular zone. To keep the coordinates positive, a large constant value is assigned to the central meridian in the State system, the computed coordinate (X') is added to this constant value when the point is east of the central meridian and subtracted when west of this meridian. For the example shown, the central meridians for both zones have assigned values of 500,000.00 feet. The station is therefore 159,410.80 feet east of the central meridian for the west zone and 159,733.54 feet west of the central meridian for the east zone. The "Y" coordinate is the distance in feet north of some parallel of latitude which is below the southernmost extremity of the zone; it is usually assigned a numerical value in feet of 0.00. (6) (or Aa angle) - The angle between the geodetic and grid meridian; often referred to as the mapping angle. These angles are applied with the opposite sign to geodetic or astronomic azimuths to obtain plane (grid) azimuths. In this example, the coordinates are computed on the transverse Mercator projection and the mapping angles are identified as Aa (delta alpha) angles. Similar values on the Lambert projection are referred to as 6 (theta) angles. Another term, the (t-T) or second term correction may be computed and applied as an additional refinement, but generally it is quite small 13 and usually can be ignored. However, the computations are rather simple (see reference no. 5, page 3) . Where significant, these corrections should be applied to the azimuths and angles in projects where a high accuracy is required. Astronomic azimuths should also be corrected for the deflection of the vertical at the point of observation when such azimuths are to control higher grade projects. This correction is known as the Laplace correction and can amount to as much as 20" in the conterminous United States, but generally is considerably smaller. Values of 5 to 7" are not uncommon, however. The NGS will furnish estimated corrections upon request. Since these estimations involve, in many cases, a review of the local topography, reasonably accurate positions of the points from which the observations were made are required. Scaled values from USGS topographic sheets are usually satisfactory for this purpose. (7) Geodetic and plane azimuths - For the more recent listings, the number of azimuths is limited to those required to compute the azimuths of the marks and objects given in that portion of the description or recovery notes known as the "box" or "box score." In earlier versions, all geodetic azimuths and distances from the station were shown, but revisions necessary to keep the listings up-to-date became too costly and the practice was discontinued. It was felt that with the availability of electronic computers, these data could be easily computed and their elimination from the format would cause little inconvenience. (8) Descriptions and recovery notes - Anyone using a station to control a survey should verify the descriptive and observa- tional data contained therein to insure that a recovery has been made. Any discrepancies should be reported to the NGS or to the establishing agency. The "DIRECTION" shown in the box does not refer to a compass bearing but to the angular direction from the initial point taken in a clockwise manner. The direction to the initial point is usually assigned a value of 0° 00' OO'.'O. The angles between any of the other points are obtained by differencing the directions involved. All points shown in the box, with the possible exception of the initial point, were visible at tripod height at the time the descriptive information was prepared. When the initial station carries the notation VG (visible from ground), it, too, can be observed from tripod height. 14 (9) Additional explanatory notes - When a point has been determined by procedures which do not provide a check, the notation "NO OBSERVATIONAL CHECK ON THIS POSITION" appears under source. The agency making the observations, if other than the NGS, is identified by the statement "Observations by " which immediately follows the station name. Other comments are added below the azimuths when needed to explain particular circumstances. In general, only the date of establishment is shown but on occasion, especially in crustal movement areas where new positions have been determined, the original date and the date of the new observations used in the new position determination are noted. "Litho" Type Format The old style horizontal control listings, commonly called "lithos," involve separate sheets for the geographic positions, plane coordinates, descriptions, and recovery notes (see fig. 5, 6, and 7). There were some advantages to this format such as all geodetic azimuths and lengths were available and the data were assembled in a more orderly fashion with regard to the actual route of the survey and the area covered; but these advantages were more than offset by the numerous sheets of paper required to complete the compilation of the data for a point. In the early forms used for this type of listing, there were other disadvantages; the order of accuracy, for example, was not indicated but could be ascertained by a review of the data as follows : (a) First-order - Azimuths to hundredths of seconds, logarithms of the distances in meters to seven places, and the distance in meters to two decimal places. (b) Second-order - Azimuths, logarithms, and distances to one less decimal or significant figure than for first-order points. Since surveys made to third-order accuracy were also listed in the same manner, it is occasionally difficult to determine the accuracy of a particular point. Any problems in this regard would generally be in the coastal regions because units other than geodetic parties may have performed the surveys. Geodetic parties seldom, if ever, perform surveys to less than second-order specifications, except to locate certain structures. But photogrammetric or hydrographic support units often establish control only to the accuracy required for the particular project involved and these accuracies may be third- order or even less on occasion. Data for surveys made to less than third-order requirements are not published, however. 15 hS Q: u *! Z ' — H 11 H . 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I CD to; c; 3 i ' I © i : k: S O: : 0:0> : I *> : W. l 3: U\ 3 a : 3 i ▼h ; « (*: i ffii-i ; o »4 i-t : Kii i • ta- O ■ 17 UNITED 3TATS3 COAST AND OEODBTIC SURVEY Deso-iptlona of Trlenguletlon Station* Shady to Lily, Florida . WOODS (Marlon County ,Fle. .H.C.W. , 1933)— Thla atatlon la •bout 4.3 miles 3 of th* courthouse In Ocala, and about 250 yarda W of the Orange Avenue maoadara road, on land owned by W.B. Woods, who llvea about 0.2 nil* 3 of the W aid* of the road. Th* station la on anolosad timber land, about 200 yarda * of a partly built rook foundation, on whloh Mr. Wooda lntenda to build a houa*. It 1* on the highest part of the hill, about 73 yarda N of th* edge of the oleared, cultivated land. The stntion la 41 fe*t W of a blated oak tree, and the mark projeota 8 Inohea. Surface, underground, referenoe and azimuth mark* are stand- ard bronze disk* aet In conorete is deaorlbed In notes la, 7a, and 11a. Referenoe mark No.l la E3E of tha station, 10 feet from th* road leading to th* station and 13 feet WNW of a pin* tree whloh Is slightly to the right of an extension of the line between th* station and the referenoe mark. The mark projects 8 inohea. Referenoe mark No. 2 la SW of the atatlon, and about 30 feet from the edge of the cleorlng. The mark projects 8 Inches. The azimuth mark la N of the station, 33 feet B of the center line of the Orange Avenue road, and projects 8 Inohea. The mark la 0.4 .mile N of the entrance to the station, and 2.2 miles 3 of the point where the turn Into Orange Avenue is msde. To reech from the oourthouae In Ocala, go 3 1.8 alias to th* Orange Avenue cross road, turn right (3) and go 2.6 riles to the rock foundation mentioned above. Turn In here and follow the dim road around the foundation to the top of the hill, and th* station. A 116-foot tower was erected first, but the line to ItARTRL was obstn-oted by a ridge about l/2 mil* W. A 136-foot tower was nsoesssry to clear the line. OBJKCT DISTANCE DIRECTION HOTEL feet O^OO'OOSO R.M.No.l 134.72 81 50 SB. 4 R.M.No.2 129.68 182 43 11.2 Aa.Mk. (Approx.) 0.4 mile 340 M 88.2 LUCIUS (Marlon County, Fla. ,H.C.W. ,1933)— Thla station la •bout 11 miles 3 of Ooala, 3.7 mllea by road SW of th* B*llevlew railroad station, 0.2 mile N of the macadam road leading from Bellevlew SW to the Orange Avenue macadam road, on tha highest point of a hill, in open timber land and on property which haa been taken over by the State for taxes. The mark is about 250 paoea S of the farmhouse owned by Mr. C.E. Lucius, 276 f*et E of the private road leading from the highway to the farmhouse, 22 feet SE of an oak tree marked with a triangular bias* and 19 feet NE of a large oharred stump. The mark projeota 8 inches above the ground. * Surface, underground, reference and azimuth marks are stand- ard bronze disks set in concrete as described in notes la, 7a and 11a. Referenoe mark No.l Is N of the station, 96 feet E of the private road and projects 12 Inches stove the ground. Reference mark No. 2 is S of the station and project* 12 Inches above the ground. The azimuth mark la 0.15 mile S of the station, 36 f**t R of tha "center line of the macadam road, 27 feet W of a oonorete culvert and projeota 12 Inches above the ground. To reach from Ocala follow U.S. Highwny 441 S about 3 miles to the Junction with a macadam road called Orange Avenue. Thla Is about 0.3 mile S of a Seaboard Airline Railroad underpass. At the Junotlon there is a filling station on either sld* of D.S. Highway 441. Turn right and follow Orange Avenue 9.4 mll*a to oroasroeds. A maoadan road leads E and a graded aand road W. Turn E and follow the macadam road 2.5 miles to the privat* road leading N to the Luoiua'a home. Follow this road N 0.2 mile to • blazed oak tree at the point where the road swings sharp left. Turn right and go 276 feet to the atatlon. OBJECT WHITE R.H.No.2 Large VThlte Bldg.(S) R.M.No.l Az.l'k. (Approx. ) Unpalnted bungalow (3) DISTANCE feet 180.00 2.5 mllea 144.09 0.15 mile 0.2 mile DIRECTION 0°00'00"0 22 31 42.2 228 26 273 53 21.9 273 46 57. 6 317 13 Height of telescope above atatlon mark - 116 feet. LUCIU3 (Marlon County, Fla , ,H.C.W. , 1933J J. 3. B., 1936 )— Station mark, referenoe and azimuth marks reoovered in good condition. Reference mark No.l Is S of the station Instead of N aa originally described. The azimuth mark la 3 of the station as described. There Is an error In mileage In deaoribing how to reaoh tha station from Ocala. It should be made to read as follows* To reach from Ocala, follow U.S. Highway 441 S about 2.0 miles or 0.2 mile S of the Seaboard Airline Railroad underpaea to road forks at a filling station on either eld* of U.S. 441. Here U.S. 441 bears left and a macadam road called Orange Avenue turns right (S). Turn right and follow Orange Avenue 9.4 mllea to crossroads. A macadam road leada E and a graded eand road W. Turn E and follow the macadam road 2.5 miles to the privet* road leading N to the Lucius ' home. Follow this road N 0.2 mil* to a blazed oak tree at the point where the road swings sharp left. Turn right and go 276 feet to the station. LUCIUS (Marlon County, Fla. ,H.C.W. , 1933 jE.B.L. , 1937 )— Station was recovered approximately as described. Marks In good oondltlon and undisturbed. Correoted description as follows! About 11 mllea S of Ooala, 3.5 mllea SW of Bellevlew, 0.2 mile N of th* macadam road loading W from Bellevlew (at junction* of U.S. Highways 441 and Florida 23) to Orange Ave. At th* highest point of a small hill, In open timber land which has been taken for taxes. Th* mark la 200 yarda E by N of C.E. Luolua' ho**. 270 feet ENE of aand road leading to the Luolua hotie. 19 f**t R of a firs blackened atump, 3 feet high, 22 feet SB of an oak tr** marked with a triangular bleto. Mark, not* lb, projeota 5 inohea. Reference mark No.l la S of station, note lib, and projeota "Reference msrk No. 2 is a standard disk set in oonoret* aa dencrlbed in note lib. Is w of the station, 30 yards E of th* center line of the sond road. It* projeota 12 inches. OBJECT MSTANCl KO0D3 feat R.U.No.l (3) 1M.06 F.H.N... 2 (*! 160.05 DIRECTION # 00*00?0 197 67 46. 306 35 66. WHITE (Marion County, Pla. , H.C.W., 1933)--Thle station la about 13 miles SSW of Ocala, in open timber land and on tha highest point of a ridge. 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Prior to the adoption of the New England Datum in 188 0, the computations were carried out on the Bessel spheroid and undoubtedly not all stations computed on this spheroid were converted to the Clarke Spheroid of 1866 when it was adopted in 1880. Many of these early stations, not included in today's published files, appeared on maps and charts and were used in surveys of the time; and indeed some may still physically exist. Nevertheless, their value in resurveys, erosion studies, and other research endeavors is considerable. Annually, numerous requests for conversion of these points to the North American 1927 Datum are received. Occasionally, the requests are of such a nature that a review of the original field records is necessary. Fortunately, these early records are readily accessible, but often the research required to resolve a particular problem entails a very large effort. In such cases, it may be necessary to require reimbursement for gathering, reviewing, and evaluating the data. Physical Geodesy Data These data refer to the physical properties of the Earth's gravity field as applied in geodesy. The fundamental para- meters are gravity intensity, astronomic position, and their temporal variations. Deflections of the vertical and geoidal separations are major elements related to the precise size and shape of the Earth. Knowledge of the intensity and direction of the gravity field at points on and above the Earth's surface is essential in studying the Earth's internal constitution, in metrology, and in space technology applications. Polar variation, or the wobble of the Earth's axis within the body of the Earth, is also included. Data are available in tabular form or, in certain cases, on charts showing contours of gravity intensity anomalies or geoidal separations. Listed gravity data are compiled for distribution by NGS . An index map is available showing the current density of stations by 1° x 1° square subdivisions. The data are in automated format and can be furnished for any selected area in the form of punch cards, printouts, or magnetic tape. A sample listing is shown in figure 10. 22 > X UJ u o 3 p+ o 3 t- a t/i CD X > UJ « a IM o u i— X vi J> UJ *■ UJ n n n n n n <1 n r\ n n n OJ 3 u e o in UJ i/i AJ « _l h- Z a o 9 9 3 o 3 9 3 3 L> o 3 D o o o O 9 3 O o O u o V) X to J* m m IM X M IM M ■M M N X N ■M M N IM IM IM IM IM IM IM IM IM 4 OJ X UJ ex L> u - o o 9 1/1 w* f- o 3 *• K o- • U <- o 3 • o 9 ot >- o» UJ -J n tr ■»■ *! n D M "M t T cr — 6> l»l m 0- r- •C n N OB 03 F^ O ■«• ■* IM n 3 m s O p» 3 u M rg :M M IM M ■M IM IM IM IM IM IM IM •M IM IM IM Cg IM rM P4 i/i O z 3 3 3 CB * ♦ ♦ ♦ * ♦ ♦ * ♦• ♦ ♦ * + ♦ ♦ ♦ ♦ ♦ * ♦ ♦ ♦ ♦ ♦ ♦ 1 1 u> at X 3 I X « t- r- . - «1 «• IM o» n CO IM * 1^ »• M ■r m «0 n rg O (XI CO o o « « o o a. ■C * i-4 « m 1 - in to r- »n T> In F! h- * m * m m in pn 41 IM «M • t UJ u IM rvj IM M N IM N IM 1 cj o UJ -c © o at « ♦ * ♦ ♦ ♦ ♦ ♦ + ♦ ♦ ♦• ♦ ♦ ♦ ♦ ♦ ' ♦ * ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ >- U. x -r D «I IM *■ at 1/) CD -J o o O 3 u o 9 O u o o o 3 3 o 3 o o o o o o O O CP •C — UJ UJ u < EC r* 1- S CM M r\ 43 O CO cr CM CO 00 1* CO p- m in m in r» «B IM 0B CD =J o O UJ u> kr> m D « K1 *i h- « in r^ * m * • CO m eg r» «p «CJ cu •O O l>- 1*" 3 9 >■ t- K a >■ IM IM CM N N N m rM N IM IM IM N IM N IT cr !• D» 0» 0» B» 0< V D< B> V 0- 0> B> «r o» IF W> e» o> o> > < Z CB J> •" >■ i- r» «■ h- * » "» r^ * r~ 1- "" N N h- r- P» r- r- (— r- r- P» r- < -J o O < IT IT o> D» IT 1 B» r B> [r o> 0» tr a> 0> B* «7> IP C7> B» V o> or V- o> o> o> a _J ex is z o IS u O o o t— 1/) M m * N rg -» N rM IM IM IM « IM IM IM IM IM IN •* * IM (M IM - UJ LU -1 I ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ <¥ ♦ UJ 1- z 3 UJ J» 1- UJ u O D O -> O u U u> O !_> O o U U O O <-> O o HI cu o p^ ■r m 1" pn m Fl Tl m m m m <»i w ro * i»i m m m IM IM (S z u O O D u o D D u u O o u D o o o c ■J (3 o (9 o *-< p* O CO CO CD CO CO CO CO CO CO CD CO cu CO CO OB CO CD CB CO CB OU CB CB CD 0B CD _J I 1 1 1 ( 1 1 1 1 • 1 1 1 1 1 1 1 1 t 1 1 1 1 1 1 1 UJ 9 D o 3 o o o o O o o 3 o o O o o o o o o o o o * l>- o r» D o ■r irv ■0 r- o p* IM IM m in CO o ■O 3 »— r» "» CO CO go CO EO CO CO (T o 0» :»> o> O- u> o o CO IM IM N fM IM IM CM rM IM IM IM N N IM IM IM IM «T> n n PI PI fn n m fn m t— « B CO CO CO ■> CO CO CO CO ai CO ■1 CO CO CO CO CD CB CB CD CD CB CB CB CO CD ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ + ♦ ♦ ♦ * ♦ ♦ ♦ ♦ ♦ ♦ ♦ 23 Astronomic data are available for more than 3,000 stations in the U. S. and territories. The data are maintained in a card file, one card for each station. Copies of the cards are furnished on request, and contain final results in latitude, longitude, and azimuth; precision figures; and deflections of the vertical where available. A sample data card is shown in figure 11. Many of these data are now available on computer listings . Anyone considering the observation of astronomical azimuths should consult the following two articles, referenced in the bibliography of this paper, prior to initiating operations: (1) Poling, Jr., A. A., 1973: Astronomical azimuths for local control. (2) Rice, D. A., 1959: Ephemeris time and universal time. Vertical Control Data Quad Type Format Figures 12 through 15 illustrate the format used in tabulating vertical control data on the quad system. The line numbers do not correspond to those shown on the State leveling diagrams nor are they necessarily the same as those assigned when the line continues into adjacent quads. In crustal movement or subsidence areas, several elevations identified by the year of observation are often listed for each bench mark. Listings by Lines In some States and localities within States which have not been completely converted to the quad-type publication, leveling control is published by lines where the numbers correspond to those shown on the State leveling diagrams. This format is quite similar to the quad type; no examples are shown here. In the oldest listings there may be no route sketch included, and the elevations are often tabulated with the bench mark descriptions rather than in separate lists. Also, for all types of listings which follow this general format, when a line extends into another State, the line number may not be identical Field Elevations Unadjusted field elevations are generally available shortly after the completion of a survey project. These data, as for any material that has not been verified or adjusted in the office, must be used with caution. 24 NOAA form 76-49 (4-71) U.S. DEPARTMENT OF COMMERCE NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION ASTRONOMY, ABSTRACT OF RESULTS LATITUDE station . . .PAVpRETTA 1934 ^ of Party L; . ? ... Baker D^ 26 Sept. 1962 Quad. . 29.0812 ^ State . Florida g- "B Observer R « B. GaSSett ..... «....^._. . . ^ --•p^ El ;iC«i'NARY " ■ >1n"aL' * ' Instrument no.' " ' * *c*h'r~6noVeter* No'r 29° 22 '06 .51. . . ' . . ± ..08 T-4 ._g>11.4 .7W. Mean Observed Latitude . . Reduction to Sea Level ( m. ). .Q«QQ. Variation of Pol A ) 29 g2 Geodetic Latitude (0 S ) ?9.°. 2.2 ' . . . .". . . 04.40* No. of Observations in Longitude ( Accepted. . 1.6 J Rejected. . . .Q . +l'-?4 * /2 TURN OFJ 06.72 * 0.08 i^;KiUf. T .x - r*Rsr™. + Deflection in the Meridian (<£ A -<£ s) ■. +2.42 u _1 8l 11 06 .809 (A J Remarks: None X y +.007 + .102 LONGITUDE _ _ _ , Station.. ^VORETTA 1934 Chief of Party L * S « Observer. P-r.B.-.Pa. 3 . 3 . 6 .^. Time ?* . ?* 1 Oct. 1962 PRELIMINARY Mean Observed Longitude Date. FINAL INSTRUMENT NO. 44.29$. O"008 T r 4 33.114 " " NO. OF SETS 04.47" 0.12 4 in Latitude . +P.\<1 CHRONOMETER NO. 7897 Arc 81.. 11 Eccentric Reduction— in Longitude^ ...*. Variation of PolA-I .0 ,1968 .BIH +.01. Astronomic Longitude (A A ) gj H # 9^11 ± °" 12 Cos * ;?715 Geodetic Longitude (A.) 8l .. 11. ...".. .' 06 .809 ( . ) . ??.°. . 22 ' 04 .404 Deflection in Longitude (A A -A C ) ~1 r99. Deflection in Prime Vertical (A A -A ) Cos .""P.«9P. . Remarks: N one X y -.003 + .102 B . PAVORETTA 1934 azimuth WELCOME 3 Station Mark_ .■ observer. . P.. . P... Howes, .N... E... Matlock d.^ 1.8, 19 Oct. 1962 Chief of Party. . S .V ?.'. . Miller Instrument No.. ** . 55 °T7. Mean Observed Azimuth Diurnal Aberration Elevation of mark ( 148 05 Accepted.. . P~. No. of Observations { n Rejected . . . A 05.66 ± 0724 +0..32 m. ) 0.00 . Sin . ...*904 . . Cos Eccentricity . .00 . ( s ) . . 2$ °. . 2.2 .'. 04 . 4p4 Variation of Pole C .1 .0 .1968 BIH . T .'97 . . 7 (A .) . . 8l°. . 11 .]. .9 6 . :^°9 Astronomic Azimuth (a A ) 148 05' 05.91 ± 0.24 («„) (A A -A S ). .71.' ?. (A A -A c )Sin<£ "—*!?■ ■ («a"«o)". Cot Laplace Azimuth 14$ 0.5 05 .3§. . -(a A -a a ) Cot ACCESSION NUMBERS 5(2 R 1902 Vol. 18,19 G-12984 A -3047 Remarks: None x - -.042" y - +.110 USCOMM-OC S424X-R7I Figure 11. — Sample data card showing astronomic data. 25 o u +J c o U < O r a i 1 1 i si o: - < " Q. 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UI 3-- UJOTU.OU. ooooooot-o 1 29 Accuracy of Horizontal Control Stations The accuracy of control points published as part of the national network is noted on the listings of geographic posi- tions or on the data sheet for each point, or can be ascertained. With few exceptions, stations forming the basic network have been established by one Federal agency (the former Coast and Geodetic Survey, now the National Ocean Survey, Office of the National Geodetic Survey). Since about 1940, the standards and specifications employed have been continually upgraded for first- and second-order surveys. At the present time, all primary arcs and area networks are accomplished to first-order (1:100,000) standards. On occasion, supplemental surveys may be performed to second-order class I (1:50,000) standards, and in rare instances to second-order class II (1:20,000) criteria. Prior to this time, most basic area networks were established to standards approaching first-order; however, because of the lack of sufficient scale and a very slight reduction in the specifications, this work has been classified as second-order. There is little doubt that with the introduction of a few measured distances most of these area nets can be upgraded to minimum first-order standards. As currently adjusted, however, the relative accuracy of many stations may barely meet the listed standard and in some isolated instances may fall below standard. Where such conditions exist, the cause in almost every case can be traced to the piecemeal manner in which the network was adjusted. Plans are underway for a new adjustment, the results of which will better reflect the excellent quality of the observations. For many years, in an effort to provide the local surveyor or engineer with convenient control, a large number of stations supplemental to the basic net was established along highways or other easy-to-reach locations. The observations involved with these points are generally of the same precision and quality as the basic stations and acceptable geometry was usually obtained; however, no effort was made to establish continuous chains. As a result, stations located quite close to one another, but not connected, may have relative accuracies somewhat less than the stated standard. At the time much of this work was accomplished, few local practitioners had the equipment or trained personnel to meet even these lower standards, and there did not seem to be any reason for concern about the possible less-than-desirable relationship of these points. About a decade ago, however, with the increased use of electronic distancers and quality theodolites at all levels of the surveying profession, it was realized this practice could no longer be tolerated; so a decision was made to connect all points which were within a specified distance. This 30 specification, known as the 20 percent rule, is rather rigorously followed. Essentially, the rule states that a connection will be made between two points whenever this distance is 20 percent or less than the total distance along the shortest directly connected route between two points. For example, in figure 16, VERONA should have been connected to KOLLATH because this distance is less than 20 percent of the shortest directly connected route, KOLLATH-HILT + HILT-VERONA. Similarly, a connection SAUK-MARXVILLE should have been made since this distance is less than 20 percent of the sum of the distances SAUK-REUTER + REUTER-ROBSON + ROBSON-MARXVILLE . When a survey is made between two unconnected stations, an evaluation such as this should be made. Should the distance be greater than 20 percent of the route as described above, satisfactory results will usually be obtained, but should it be less, there is a good chance that excessive closures may result. HILT MINIX MERRIMAC KOLLATH FITCHBURG (USGS) ROBSON _ REUTER ..UK MARXVILLE MINIX Figure 16. --Samples where problems may exist because of the relative locations of stations. 31 Another method for evaluating the control in a locality is to measure lines of the network at every opportunity. By comparing these measurements with computed or published distances, the scale differentials can be determined, and, often, a better understanding of the survey closures can be obtained. Whenever difficulties are encountered, the agency that published the data should be consulted. Often a review of the computations or a check of the field records can resolve or at least clarify a problem. On occasion, revisions will be made to the published data when serious distortions in the network are uncovered by additional observations. When these recomputa- tions are made, observations secured by other organizations, private and public, will be included, providing the data furnished were obtained by acceptable survey practices. APPLICATION Geodetic data have numerous applications, some having little to do with surveying per se , but no effort is made here to expound on this subject except to note that the results of geodetic operations affect everyone's daily life in one way or another* The publications listed in the bibliography contain numerous examples of the application of geodetic data. In a publication of this size, it is the author's opinion that the possible solution to a particular problem is more worthwhile than an enumeration of the attributes of geodetic control data. Accordingly, one of the main complaints expressed by users is the lack of orientation at a station site or the blockage of the lines of sight to the azimuth mark or some other point which could be used to provide orientation. On these occasions, the only solution would seem to be astronomical observations. In many instances, however, a variety of "tricks of the trade" can often be used; so the astronomic work may not be necessary. Figures 17, 18, and 19, and the accompanying text, describe some of the methods that have proven successful. In addition to these procedures, there are numerous other geometrical and trigonometrical innovations that can be employed by imaginative surveyors. These practices would not be suggested for surveys where results better than 1:15,000 are expected, but could be used in higher grade surveys as a check, providing good quality orientation has been introduced elsewhere in the traverse. In the examples shown in figures 17 and 18, A is a point on a traverse terminating at control point FIXED. The line between FIXED and its azimuth mark is obstructed. An intersection point may be substituted for the azimuth mark in the example 32 FIXED Azimuth Mark (1) Measure distances shown by two parallel cross hashes . (2) Measure angle at A. (3) Compute angle at Azimuth Mark by side-angle-side computation. (4) To obtain the azimuth A to Azimuth Mark, apply computed angle at Azimuth Mark to grid (plane) azimuth FIXED to Azimuth Mark. In this example, the computed angle would be subtracted. Figure 17. — Example of establishing azimuth control by computation using observed angles and distances. FIXED (1) Observe angles as indicated by full lines ■ no distances are necessary (assume a distance for one line and compute other lines) (2) Compute angle at FIXED between Azimuth Mark and A by side-angle-side computation and use to determine the azimuth FIXED to A. Azimuth Mark Figure 18. — Example of establishing azimuth control by computation using triangulation procedures . 33 shown in figure 18. Since this point would not normally be occupied, extra care must be exercised in making the observa- tions. In this case, a check of sorts would be obtained by using the traverse distance A to FIXED in the computation and comparing the computed distance between FIXED and the intersection point with that obtained from the published data The triangle closures should seldom exceed 5". In the example shown by figure 19, A is a point on a traverse terminating at control point FIXED (1) . No azimuth control is available at FIXED (1) , but orientation can be obtained at FIXED (2) . FIXED (1) and FIXED (2) are not intervisible, of course; however, the azimuth could be carried between the points through one or more intermediate points. A FIXED Azimuth Mark Q Figure 19. — Example of establishing azimuth control by angulation from adjacent control stations . (1) Observed angles as indicated; no distances between FIXED (1) and FIXED (2) are required. (2) Starting with the grid azimuth FIXED (2) -Azimuth Mark, compute the grid azimuth FIXED (1)-A using the observed angles. The distribution of the azimuth closure should be made from FIXED (2) through FIXED (1) to azimuth control. 34 BIBLIOGRAPHY These publications are cited as background material for the reader. Although some may be out of print, they remain a part of the surveying literature. Availability of each document is indicated by one of the following codes that appears at the end of the citation: * This publication is out of print. It is on reference in any national depository library, and can be requested for viewing through your local library. A single facsimilie copy may be obtained, at no charge, by writing to the National Geodetic Survey Information Center, C18, NOAA, Rockville, Maryland 20852. A Out of print. No copies available. + For sale by the Superintendent of Documents, U. S. Government Printing Office, Washington, D. C. 20402. o For sale by the National Technical Information Service, U. S. Department of Commerce, 5285 Port Royal Road, Springfield, Virginia 22151. d A single copy can be furnished by the National Geodetic Survey Information Center, CIS, NOAA, Rockville, MD 20852 # This publication may be purchased from the American Congress on Surveying and Mapping, 210 Little Falls Road, Falls Church, Virginia 22046. Adams, O. S., 1936: Azimuths from Plane Coordinates 3 Serial No. 584. U. S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA), Washington, D. C. , 14 pp. * Adams, 0. S., and Claire, C. N., 1935, reprinted 1971: Manual of Plane-Coordinate Computation^ Special Publication No. 193. U. S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA), Rockville, Maryland 20852, 271 pp. A (Refer to a more recent publication by Dracup et al . , 1973: Surveying Instrumentation and Coordinate . . . Notes, listed in this bibliography.) Baker, L. S., 1968: Specifications for Horizontal Control Marks, Technical Memorandum C&GSTM-4. U. S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA), Washington, D. C, 14 pp.* 35 Brittain, J. H., 1935: Control Surveys and Their Uses, Serial No. 58 3. U. S. Department of Commerce , Coast and Geodetic Survey (now National Ocean Survey, NOAA) , Washington, D. C, 13 pp . Brittain, J. H., 1940: Computation of Traverse by Plane Coordinates , Serial No. 624. U. S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA) , Washington, D. C, 7 pp. Claire, C. N. , 1968, reprinted with corrections 1973/1976: State Plane Coordinates by Automatic Data Processing , Publication 62-4. U. S. Department of Commerce, Environmental Science Services Administration (now NOAA), Rockville, Maryland 20852, 68 pp. d Coast and Geodetic Survey, : Plane Coordinate Projection Tables, Special Publication series (available for all States except Alaska. Computations for Alaska are made using the 2h minute intersection tables, USCSGS Publication 65-1, Part 49 for zone 1, Part 50 for zones 2-9, and Part 51 for zone 10) . U.S. Department of Commerce, National Ocean Survey, NOAA, Rockville, MD 20852. (GPO has a supply for some States. Please ascertain GPO availability before contacting NOAA.) + D Coast and Geodetic Survey, revised 1940, reprinted 1941/1961: Use of Coast and Geodetic Survey Data in the Surveys of Farms and Other Properties , Serial No. 347. U. S. Department of Commerce, National Oceanic and Atmospheric Administration, Washington, D. C, 12 pp.* Coast and Geodetic Survey, 1949, reprinted 1971: Sines, Cosines , and Tangents , ten decimal places with ten-second interval , 0°-6°, Special Publication No. 246. U. S. Department of Commerce, National Oceanic and Atmospheric Administration, Washington, D. C, 36 pp. + Coast and Geodetic Survey, revised 1957: Horizontal Control Data, Special Publication No. 227. U. S. Department of Commerce, National Oceanic and Atmospheric Administration, Washington, D. C, 23 pp . + Coast and Geodetic Survey, revised 1961: Control Leveling , Special Publication No. 226. U. S. Department of Commerce, National Oceanic and Atmospheric Administration, Washington, D. C. , 20 pp. D racup, J. F. , 1969, revised 1973: Suggested Specifications for Local Horizontal Control Surveys , Technical Monograph No. CS-1. American Congress on Surveying and Mapping, Washington, 36 Dracup, J. F. , 1970: Standards and specifications for supplemental horizontal control surveys. Proceedings of American Congress on Surveying and Mapping 3 30th annual meeting, ACSM/ASP, Washington, D. C, pp. 509-534. a Dracup, J. F. , 1970: Trilateration -- a preliminary- evaluation, Proceedings of the ACSM/ASP Technical Conference 3 Denver, ACSM/ASP, Washington, D. C, pp. 95-127. a Dracup, J. F., 1972: Use of control for land surveys (preprint). Presented to Arkansas Association of Registered Land Surveyors - Arkansas Section American Congress on Surveying and Mapping 5th Annual Convention, Hot Springs, Arkansas, National Ocean Survey, NOAA, Rockville, Maryland, 26 pp. Q Dracup, J. F. , 1973/1974: Fundamentals of the State plane coordinate systems (preprint) . Presented as a one-day comprehensive course to 25th Annual Surveyors Institute, University of Wisconsin, Madison, December 1973; presented at seminar, Professional Land Surveyors of Ohio, Akron, October 1974, 60 pp. a Dracup, J. F., 1975: The Alaska coordinate system (preprint). Presented to Surveying Computation Workshop, Alaska Surveying and Mapping Convention, Anchorage. National Ocean Survey, NOAA, Rockville, Maryland, 63 pp. o Dracup, J. F., 1975: Application of National Geodetic Survey practices to local control surveys (preprint) . Presented to New England Section American Congress on Surveying and Mapping - Maine Society of Surveyors Workshop, Rockport, Maine. National Ocean Survey, NOAA, Rockville, Maryland, 3 pp. o Dracup, J. F., and Kelley, C. F., 1973, reprinted 1975: Horizontal Control as Applied to Local Surveying Needs. American Congress on Surveying and Mapping, Washington, D. C. , 127 pp. # Dracup, J. F. , Kelley, C. F., Lesley, G. B., and Tomlinson, R. W., 1973: Surveying Instrumentation and Coordinate Computation Workshop Lecture Notes. Control Surveys Division, American Congress on Surveying and Mapping, Washington, D. C, 208 pp. # Federal Geodetic Control Committee, 1974 , reprinted 1975/1976: Classification } Standards of Accuracy 3 and General Specifica- tions of Geodetic Control Surveys. U. S. Department of Commerce, National Oceanic and Atmospheric Administration, Rockville, Maryland 20852, 12 pp. (to be used jointly with next publication cited, "Specifications to Support . . .") oo 37 Federal Geodetic Control Committee, 1975, 1976: Specifications to Support Classification, Standards of Accuracy 3 and General Specifications of Geodetic Control Surveys . U. S. Department of Commerce, National Oceanic and Atmospheric Administration, Rockville, Maryland 20852, 30 pp. o o Gossett, F. R. , 1950, revised 1959, reprinted 1971/1974: Manual of Geodetic Triangulation 3 Special Publication No. 247. U. S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA) , Washington, D. C, 344 pp. + Hodgson, C. V., 1929, revised 1935, reprinted 1957/1961: Manual of Second- and Third-Order Triangulation and Traverse 3 Special Publication No. 145. U. S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA) , Washington, D. C, 226 pp.D Holdahl , J. H., and Dubester, D. E., 1971: A computer program for traverse adjustments using plane coordinates. Proceedings of American Congress on Surveying and Mapping 3 31st Annual Spring Meeting, ASP/ACSM, Washington, D. C, pp. 562-572. a [Documentation for this program can be found in: Holdahl and Dubester, 1972: A computer program to adjust a State plane coordinate traverse by the method of least squares (preprint) . National Ocean Survey, NOAA, Rockville, Maryland, 234 pp. (A traverse update, 12/01/72, 7 pp., accompanies this documentation.)] o Hoskinson, A. J., and Duerksen, J. A., 1952: Manual of Geodetic Astronomy 3 Determination of Longitude 3 Latitude 3 and Azimuth 3 Special Publication No. 237. U. S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA) , Washington, D. C, 205 pp. o Howe, H. H., and Hurwitz, L . , (1964, 3rd ed . ) , reprinted 1969: Magnetic Surveys 3 Serial No. 718. U. S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA) , Washington, D. C, 20 pp . A Kaufman, H. P., undated: The ABC of Triangulation Adjustment, Publication G-45. U. S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA), Rockville, Maryland, 14 pp. * Kelley, C. F., 1971: What data? Proceedings of American Congress on Surveying and Mapping. ASP/ACSM Fall Convention, San Francisco, ACSM, Washington, D. C, pp. 407-433. o 38 Meade, B. K. , 1964: The practical use of the Oregon State plane coordinate system (preprint) . Presented at the Surveying and Mapping Conference, Oregon State University, Corvallis. U. S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA) , Washington, D. C. , 26 pp. o Mitchell, H. C, 1950: Use of State Plane Coordinates in Route Surveying 3 unnumbered USC&GS publication. U. S. Department of Commerce, National Ocean Survey, NOAA, Rockville, Maryland, 11 pp. * Mitchell, H. C, 1948, reprinted 1974/1976: Definition of Terms Used in Geodetic and Other Surveys _, Special Publication No. 242. U. S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA), Washington, D. C. , 87 pp. d Mitchell, H. C, and Simmons, L. G. , 1945, revised 1974, reprinted 1975: The State Coordinate Systems (A Manual for Surveyors ) _, Special Publication No. 235. U. S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA), Washington, D. C, 62 pp. + Poling, A. C. , 1947: Elevations From Zenith Distances (machine computation with 6-place natural tangent tables) 0°-45° 3 USC&GS Publication G-56. U. S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA) , Rockville, Maryland, 3 pp. * Poling, Jr., A. A., 1973: Astronomical azimuths for local control (preprint) . Presented to Joint American Society of Photogrammetry/American Congress on Surveying and Mapping Convention, March 1967. National Ocean Survey, NOAA, Rockville, Maryland, 10 pp. o Rappleye, H. S., (1948) 1963/1976: Manual of Geodetic Leveling } Special Publication No. 239. U.-S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA) , Washington, D. C, 94 pp.0 Rappleye, H. S., (1948) reprinted 1975: Manual of Leveling Computation and Adjustment, Special Publication No. 240. U. S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA), Washington, D. C, 178 pp. a 39 Reynolds, W. F. , 1934, reprinted 1934/1965: Manual of Triangulation Computation and Adjustment 3 Special Publication No. 138. U. S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA) , Washington, D. C. , 242 pp. a Rice, D. A., 195 : Ephemeris time and universal time. Surveying and Mapping, XIX 3 (3) 3 pp. 367-370. Simmons, L. G. , (1968), reprinted 1975: Geodetic and Grid Angles - State Coordinate Systems 3 ESSA Technical Report C&GS 36. U. S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA), Rockville, Maryland, 5 pp . * Thorson, C. W. , (1965) 1967: Second-Order Astronomical Position Determination Manual 3 Publication 64-1. U. S. Department of Commerce, Coast and Geodetic Survey (now National Ocean Survey, NOAA), Washington, D. C, 78 pp. * Tomlinson, R. W. , and Burger, T. C, (1971) revised 1975: Electronic Distance Measuring Instruments 3 Technical Monograph No. CS-2. Control Surveys Division, American Congress on Surveying and Mapping, Washington, D. C, 68 pp. # ftU.S. GOVERNMENT PRINTING OFFICE: 1976 210-801/310 1-3 PENN STATE UNIVERSITY LIBRARIES AD0DQ72DmM2D NOAA--S/T 76-2190