DRAFT CHAPTER 10 FIELD NOTES

Transcription

1 CHAPTER 10 FIELD NOTES The field notes of any survey are the only original record of the survey that the survey team has once it leaves the field. Therefore, the field recorder's notebook must contain a complete record of all measurements made or determined during the execution of the survey. It should include complete sketches, descriptions, and remarks, when necessary, to clarify the notes. The best survey fieldwork is of no value to the team if the notes are not accurate, legible, and complete in every detail Recorder s Notes a. General. The field recorder's notebook designated as DA Form 4446; Level, Transit, and General Survey Record Book, will be used until stocks are depleted. Currently a "new" version of the field recorder's notebook will be issued when replenishment is requested. The following text applies to any, and all recorder's notes, regardless of the edition. 1. It is a hardback, permanently bound book for recording all data necessary for computations, problem solving, and archiving of field surveys. The recorder's notebook is considered a legal document, and should be treated as such during the course of recording survey fieldwork. b. Duties of the Survey Recorder. The recorder is responsible to maintain the only original record of all field measurements and any occurrences, which may affect those measurements. He must also be thoroughly trained in the requirements for all survey methods. His duties include the following: Neatly and legibly records all survey data. Checks and means angular data. Records and means distances. Provides required data to the survey computers. c. Recorded Data. Data recorded for a field survey includes, but is not limited to, the following: 1. Measurements. Field measurements such as horizontal angles, vertical angles, and distances from the instrument operator must be recorded. 2. Sketches. All surveys should include a sketch. The sketch must be oriented with a north arrow and should be as close to scale as possible. In a long survey, the sketch may be separated over several pages. 3. Descriptions. Descriptions of stations necessary to supplement the sketch should be written in the remarks section. This would include distances from objects used to locate a station, type of marker, etc. Any changes to descriptions in a trig list should also be noted for submission to controlling agencies. 4. Remarks. The remarks section should include any remarks necessary to clarify survey data. These remarks could include descriptions of extreme weather phenomena, and explanations of voided angles and pages. Some survey methods have required entries for the remarks section. These required entries are listed in the sections describing that method of survey. Temperature and pressure entries used as corrections for the DI3000, instrument heights, and target heights should also be included Rules For Recording Field Notes a. General. Recording field notes is regulated by certain rules that apply to all methods. For the most part, these rules are designed to ensure consistency between different recorders and to aid in the legibility and neatness of the data. All recording will be done in pencil. Be sure the pencil is sharpened to a fine point. Never erase in the recorder's notebook. Use only upper case letters. Do not slant letters and numbers. Do not strike over letters or numbers. Use approved abbreviations and symbols Use a straight edge and protractor for the sketch. 10-1

2 Record directly into the recorder's book. Never record into an extract or on paper, and then transcribe recorded data to the recorder's notebook. Do not use the pages of the recorder's book to perform math computations, use scratch paper. b. Abbreviations. When recording field notes, certain abbreviations can be used. Some are listed below: AZMK COP D DIST FWD GN HI HORZ HT IO MN OCC R RCDR READ SCP STA VERT Azimuth Mark Chief of Party Direct Distance Forward Grid North Height of Instrument Horizontal Height of Target Instrument Operator Mean Occupied Reverse Recorder Reading Survey Control Point Station Vertical 1. The designation block will be filled in with the word "INDEX". 2. The date block will be filled in with the date the book was officially opened, usually the day the first survey in that book was performed. 3. No information will be listed heading blocks on the right side. 4. The column titles under the heading will be labeled (from left to right) as follows: a. Column 1: PAGE; to identify the page number that includes a particular set of survey data. b. Column 2: DATE; lists the date written in the date block of that particular page. c. Symbols. When recording field notes, it is sometimes necessary to use symbols, especially in the sketch. As a general rule, the symbols in the legend of a map sheet from the area of operations should be used. (See Figure 10-1.) d. Index. The first numbered page of the recorder's book is the index. Page one includes both the left and right sides. The heading and column blocks for the index are set up as follows. (See Figure 10-2.) Figure 10-1 Standard Symbols for Recording Figure 10-2 Index Page 10-2

3 c. Column 3: TITLE; lists the designation written in the designation block of that particular page. d. Columns 7, 8, and 9: Same as columns 1, 2, and 3 respectively Recording For Methods Not Included In This Chapter a. GPS-S Surveys. Recording procedures for RTK/OTF are discussed in the 4000 MSGR job aids. b. PADS. Recording procedures for PADS operations are discussed in Chapter 6 of this text. c. Astronomic Observations. Recording procedures for astronomic observations are discussed in Chapter 8, text Recording A One-Position Angle a. General. The procedures listed below are for recording a one-position angle. This type of angle is used for both fourth and fifth order traverse, as well as most fifth order conventional methods and PADS autoreflection. b. Heading and Column Titles. The heading and column titles will be filled out as described below. (See Figure 10-3.) 1. The designation block will be filled in with the survey method (e.g., Traverse, Triangulation, etc.) being conducted. Other entries may be included after the method of survey. 2. The date block will be filled in with the date the fieldwork was performed. 3. The heading of the right side of the page will be filled out as follows: (See Figure 10-3) b. Inst: The instrument types and serial numbers will be listed on the left side of the second line of the header. This will help identify which instruments may require adjustments due to errors. c. Team Members. The Chief of Party (COP), instrument operator (IO), and recorder (RCDR) will be listed at the right side of the right page, above the top line. 4. Column titles will be filled in as follows: a. Column 1: STA; to identify the occupied, rear, and forward stations. b. Column 2: T; to identify the telescope mode, direct (D), or reverse (R). c. Column 3: HORZ; to record horizontal readings measured at the occupied station and the mean horizontal angle used for computations. d. Column 4: MEAN; to record the mean of the direct and reverse horizontal readings at the forward and rear stations. e. Column 5: VERT READ; to record vertical readings measured by the IO. f. Column 6: VERT; to record direct and reverse vertical angles calculated by the RCDR from the vertical readings and to record the mean vertical angle used for computations. g. Column 7: SLOPE DIST; to record slope distances from the DI3000. If only horizontal distances are measured, then this column will be titled DIST. h. Columns 8-12: REMARKS; columns 8-12 will be used to record any information pertinent to the measurements and subsequent computations. a. Weather: Weather conditions will be listed at the left side of the top line. It is a two-word description of the weather, (e.g. sunny, cold.) Figure 10-3 Heading and Column titles 10-3

4 c. "STA" and "T" Columns. The "T" (telescope) column will be filled out as shown in figure The rear station (AzMk) name will be recorded in the direct (D) mode row directly below the "STA" column title. Skip one line and record the occupied station name. Skip one line and record the forward station name. 3. Figure 10-6 shows an example of data recorded with means computed. Note that only data that will be used by the computer is circled Recording A Two-Position Angle a. General. The procedures listed below are for recording a two-position angle. This type of angle is required for certain fourth order methods such as triangulation and trig traverse. Use of this method of angle determination for other survey methods is a matter of local SOP. b. Heading and Column Titles. Heading and column titles for a two-position angle are the same as for a oneposition angle. (See Figure 10-3.) c. "STA" and "T" Columns. The "STA" and "T" columns for a two-position angle are the same as for a one-position angle. The second angle is started two spaces below the first angle. (See Figure 10-4.) d. Recording Field Data. Figure 10-4 "STA" and "T" Columns d. Recording Field Data. 1. Field data will be recorded in the columns and rows corresponding to the pointing. For example, when the instrument operator determines the initial circle setting, the theodolite is in the direct mode, pointed at the rear station, and the measurement is determined from the horizontal circle. With this in mind, the initial circle setting must be recorded in the horizontal angle column; in the direct mode row for the rear station. 2. Figure 10-5 shows the standard sequence that measurements should be made and recorded for a oneposition angle. 1. The first of the two measured angles is determined exactly the same as a one-position angle. 2. The second of the two measured angles is the same as it is for a one-position angle except that the initial circle setting for the second angle will be mils, ± mils. 3. Vertical angles and distances are determined during the first position angle. 4. The mean of the two position angles is determined by adding the two angles together, then dividing that 5. When a two position angle is observed, the two measured angles must agree within mils. If they differ by more than mils, both angles must be rejected and measured again. Figure 10-5 Standard Order for recording a One-position Angle 10-4

5 Figure 10-6 Example of a completed One-Position Angle Figure 10-7 Example of a completed Two- Position angle 10-5

6 6. Figure 10-8 shows an example of data recorded with the means computed. Note that the mean horizontal angle of each position angle is recorded in parenthesis; the mean of the two position angles is circled Closing an Angle On the Horizon a. General. 1. The procedures listed below are for recording an angle closed on the horizon. This type of angle can be used when a two-position angle is required or as local SOP directs. 2. Closing on the horizon simply means that the second angle measured closes a horizontal circle at 6400 mils. The first angle is the station angle; the second is the explement angle. (See Figure ) position angle except that the rear and forward stations are reversed to measure the rest of the horizontal circle. 3. Vertical angles and distances are determined with the station angle. 4. The sum of the station angle and the explement angle would equal 6400 mils if no error were present. The mean horizontal angle is determined by applying half of the error (from 6400 mils) to the station angle. (See Figure 10-9.) 5. When an angle closed on the horizon is observed, the sum of the two measured angles must be within ± mils of 6400 mils. If the sum differs from 6400 by more than mils, both angles must be rejected and measured again. 6. Figure 10-9 shows an example of data recorded with the means computed. Note that the mean horizontal angle of each measured angle is recorded in parenthesis; the corrected station angle is circled Recording Reciprocal Vertical Angles a. General. When conducting a fourth order traverse, or surveying a traverse leg of more than 1000 meters, measurement of reciprocal vertical angles is required. b. Heading and Column Titles. Heading and column titles, (for columns 1-6), are the same as for a one position angle. Columns 7-12 are discussed below. (See Figure ) 1. Column 7: MN RECIP VERT; to record the mean of the reciprocal vertical Figure 10-8 Angle Closed On The Horizon b. Heading and Column Titles. Heading and column titles for an angle closed on the horizon are the same as for a one-position angle. (See Figure 10-3.) c. "STA" and "T" Columns. The "STA" and "T" columns for an angle closed on the horizon are the same as for a one-position angle. The explement angle is started two spaces below the position angle. (See Figure 10-9.) d. Recording Field Data. 2. Column 8: SLOPE DIST; to record slope distances from the DI3000. If only horizontal distances are measured, this column will be titled DIST. 3. Columns 9-12: REMARKS; these columns will be used to record any information pertinent to the measurement and subsequent computations. c. "STA" and "T" Columns. The "STA" and "T" columns for recording a reciprocal vertical angle are labeled the same as for a one-position angle; however, if the top angle on the page includes a vertical angle to the rear station, the first row below the column titles will be skipped (See Figure ) 1. The station angle is determined exactly the same as a one-position angle. 2. The explement angle is the same as it is for a 10-6

7 Figure 10-9 Example of an Angle closed on the horizon Figure Example of recording with Reciprocal Vertical Angles 10-7

8 d. Recording Field Data. 1. Vertical angles are measured to the rear station the same as they are to the forward station. Vertical readings are measured and recorded when the horizontal readings are made; in other words, the vertical reading to the rear station in the direct mode is made directly after the initial circle setting is recorded. 2. Vertical angles determined by the recorder that will be included in the mean of reciprocal vertical angles will be recorded in parenthesis. The mean of the reciprocal vertical angles will be circled and recorded in column 7, in the row corresponding to the mean angle at the occupied station Recording Angles From An M2A2 Aiming Circle a. General. Angles measured with an M2A2 Aiming Circle are generally used for hasty survey purposes. Hasty survey is discussed in Chapter 11 of this text. As with all field notes, the first page of the field recorder's notebook is the index. b. Heading and Column Titles. The heading and column titles will be filled out as described below. (See Figure ) 1. The designation block will be filled out with the survey method (e.g., Hasty Traverse) being conducted. Other entries may be included after the method of survey. 2. The date block will be filled out with the date the fieldwork was performed. 3. The heading of the right side of the page will be filled out as follows: (See Figure ) a. Weather: Weather conditions will be listed at the left side of the top line. It is a two-word description of the weather. (e.g., clear, warm) b. Inst: The instrument types and serial numbers will be listed on the left side of the second line of the header. c. Team Members. The Chief of Party (COP), instrument operator (IO), and recorder (RCDR) will be listed at the right side of the right page, above the top line. 4. Column titles will be filled in as follows: a. Column 1: STA; to identify the occupied, rear, and forward stations. b. Column 2: R; to identify the reading. c. Column 3: HORZ; to record the horizontal readings and the mean horizontal angle. d. Column 4: VERT; to record the uncorrected vertical angle to the forward station. e. Column 5: CORR; to record the vertical angle correction determined during operator tests. f. Column 6: CORR VERT; to record the corrected vertical angles and the mean corrected vertical angle. g. Column 7: SUBT DIST; to record the subtended distance as extracted from the subtense tables in the FM 6-50 and XO's handbook. This column may also be labeled for the subtended angle or horizontal distance if taped or paced. Figure Heading and Column Titles M2A2 10-8

9 h. Columns 8-12: REMARKS; columns 8-12 will be used to record any information pertinent to the measurements and subsequent computations. c. "STA" and "R" Columns. The "STA" and "R" columns will be filled out as shown in Figure The rear station name will be recorded directly below the "STA" column title. The occupied station name will be recorded directly below the rear station. The forward station name will be recorded directly below the occupied station. A "1" will be recorded in the row Directly below the "R", a "2" below the "1", and MN will be recorded directly below the "2". b. If the second reading is less than the first reading; the mean horizontal angle is computed by adding 6400 mils to the second reading, then dividing by 2. The mean horizontal angle is circled. c. The mean horizontal angle must match the first reading within mils. If not, the angle must be void and measured again. 4. Figure shows an example of recorded data for a hasty traverse Recording Intersection Method a. General. The intersection method is the Marine surveyor's preferred method of providing target location, when the target cannot be occupied. The recording method described below is used when computation of the target location is performed with azimuths measured to the target, vice horizontal angles. Figure "STA" and "R" Columns (M2A2) d. Recording Field Data. 1. The horizontal, vertical, and subtended angles are recorded to the nearest 0.5 mils. 2. A subtended distance is recorded directly out of the FM 6-50 or the XO's handbook. 3. The mean horizontal angle is recorded to the nearest 0.1 mil. a. If the second reading is greater than the first reading; the mean horizontal angle is computed by dividing the 2nd reading by 2. The mean horizontal angle is circled. b. Heading and Column Titles. The heading and column titles will be filled out as described below. (See Figure ) 1. The designation block will be filled out with the survey method (i.e. Intersection) being conducted. Other entries may be included after the method of survey. 2. The date block will be filled out with the date the fieldwork was performed. 3. The heading of the right side of the page will be filled out as follows: (See Figure ) a. Weather: Weather conditions will be listed at the left side of the top line. It is a two-word description of the weather, (e.g., clear, hot) Figure Example of recording Angles for M2A2 10-9

10 b. Inst: The instrument types and serial numbers will be listed on the left side of the second line of the header. c. Team Members. The Chief of Party (COP), instrument operator (IO), and recorder (RCDR) will be listed at the right side of the right page, above the top line. 4. Column titles will be filled in as follows: a. Column 1: OCC STA; to identify the occupied stations. b. Column 2: AZ TO AZMK; to record the computed azimuth to the rear station. This is the azimuth set on the horizontal scale of the aiming circle. c. Columns 3-5: TARGET DESCRIPTION; to identify the target, forward station. d. Column 6: AZ TO TGT; to record the measured azimuth to the target. e. Column 7: VERT; to record the vertical angle to the target. f. Columns 8-12: REMARKS; columns 8-12 will be used to record any information pertinent to the measurements and subsequent computations. c. Recording Field Data. Field data for an intersection is recorded as described below: 1. The azimuth to the azimuth mark is recorded to the nearest 0.5 mils. 2. The azimuths and vertical angles to the targets are recorded to the nearest 0.5 mils. 3. The target description should be adequate for another observer to identify that particular target. 4. Figure shows an example of recorded data for a target area intersection Correcting Errors and Voiding a. Correcting Errors. The recorder must make entries small enough that if an error is made in the data, there is sufficient room left in the block to write the correct data. (See Figure ) 1. When a value is recorded incorrectly, the value is lined out with a single straight line and the correct value written above the lined o 2. Errors will not be erased in the recorder's notebook. Figure Heading and Column Titles (Intersection) Figure Example of Completed Intersection Method (M2A2) 10-10

11 b. Partial Void. A partial void is used to void an area of a recorder's page. This is usually done over a single angle. When this occurs, the reason for the partial void must be included in the remarks section. A partial void is performed by sketching an "X" over the area to be void, using a straight edge, and writing "VOID" over the "X". (See Figure ) c. Full Page Void. A full-page void is used to void every entry made on a recorder's page. This is usually done when voiding two position angles, angles closed on the horizon, and astronomic observations; these methods all require the use of the entire page. When this occurs, the reason for the void must be included in the remarks section. Sketching an X performs a fullpage void over each page, using a straight edge, and writing "VOID" over the "X" on each page. (See Figure ) Security of Field Notes a. General. The information maintained in the recorder's book could provide the enemy with a large amount of valuable information if it were to fall into his hands. 1. The recorder's book can provide the enemy with information he could use to locate firing positions, radar sites, met sites, OPs, etc. 2. The recorder's book also includes names of personnel, equipment types, locations of survey control points, and other information that can be used for intelligence purposes. Figure Example of correcting an error and a Partial Void 10-11

12 Figure Example of a Full Page Void b. Safeguarding the Recorder's book. In a contingency situation, the recorder's notebook must be safeguarded from the enemy. 1. Some of the information recorded could actually be classified (e.g., OS coordinates, Survey Control Point coordinates, etc.); therefore, the book becomes classified. 2. When the threat of capture becomes imminent, a decision must be made as to the disposition of the Recorder s notebook. If the capture cannot be avoided, the recorder's notebook must be destroyed Storing The Recorder's Notebook a. The recorder's book should be used until filled then properly stored to eliminate damage. The storage area must be dry and safe from accidental damage such as spills. in the establishment of permanent control, the recorder's notebooks must be maintained at least as long as those control points are in tact or until they are resurveyed. 2. Recorder's notebooks containing information used in the establishment of non-permanent control must be maintained for at least the same amount of time as position safety, per local SOP. 3. Recorder's notes may be maintained for archive purposes; in other words, if a unit establishes survey control, permanent or non-permanent, in an area that is not used very often, or had not been used before; the recorder's notebook could include information necessary for planning future operations in that area. b. The recorder's notebook must be maintained for at least the minimum times as discussed below. 1. If a recorder's notebook includes information used 10-12