Page 781 records and reports 8324 



[Abstract of Buoy to Buoy Azimuth, Form 718. 

 [Azimuth by Inclined Angle, Form 720. 



(3) Position computations (Form 27). 



Insofar as possible, the records and computations for each buoy station shall be 

 assembled in the folders in the order in which the traverse was computed. 



A short report should be typewritten on letter-size paper and be forwarded with 

 the records and computations. In it the details of the traverse should be briefly 

 described under the following headings, insofar as applicable: 



A. Project. — The proper number should be given, and the method used to control the hydrog- 

 raphy should be described briefly. 



B. Layout of scheme. — The general layout of the scheme of control buoys should be explained, 

 imusual features of the scheme should be described, and any influencing factors should be discussed. 



C. Determination of positions. — The method of locating each tie-in buoy station and each buoy 

 station not in the traverse should be given. Where a method described in this Manual is used, it 

 may be identified simply by the proper reference number. 



D. Traverse closures. — For each traverse, the length of the traverse, the total closing error (in 

 meters), and the closing error (in meters) per statute mile, shall be tabulated. The average closing 

 error per statute mile for all the traverses shall also be given. Any method or expedient used in the 

 computations or adjustment of the traverse to reduce the error of closure shall be explained. 



E. Statistics. — The following statistics should be included: 



Number of buoy stations located by observations on shore stations. 



Number of buoy stations located by traverse. 



Number of buoy stations located by observations on traverse stations. 



Total number of buoy stations located. 



Number of sun azimuths observed. 



Total length of traverse (in statute miles). 



The above report need not include any description of the buoys used, the method 

 of anchoring the buoys, the field methods used, or any other such details, for they 

 will be apparent from the other information given. 



The following records should be bound with and be made a part of the report: 



a. Sketch of buoy-control scheme on letter-size paper or tracing cloth. The relative positions and 

 the names of the buoy stations of the traverse should be shown, and the relative positions of the 

 shore stations (names are not necessary) used in locating the tie-in buoy stations. The approximate 

 limits of the area surveyed should also be delineated. 



b. Record of log tests (see 4454) . 



c. Record of taut-wire calibration (see 4467) . 



d. Traverse adjustment (see 944). 



8324. Locations by R.A.R. Distances 



Buoy stations are frequently located by R.A.R. where the survey is controlled 

 by R.A.R. and stations are required far ofi"shore. The forms on which the data are 

 tabulated, Form 713, Buoy to Buoy Distances by Bomb, and Form 715, Abstract of 

 Bombed Distances, should be arranged in chronological order and bound in a folder for 

 transmittal to the Wasliington Office. 



A short typewritten report should be included. The report should describe briefly 

 the methods used to determine the positions; and if by a graphic plot, the scale of the 

 projection should be given. Where the distance arcs to any station do not intersect 

 near a point, and a position is accepted based on unequal weighting of the measure- 

 ments, the reason for this must be stated. The graphic plot should not be sent to the 

 Office but it should be retained until the hydrographic survey has been verified and 

 reviewed. 



