3. The process of making only those measure- ments   that   are   consistent   with   the   accuracy requirements Experience is of great value, but in the final analysis,  it  is  the  exercise  of  a  good,  mature, and   competent   degree   of   common   sense   that makes  the  difference  between  a  good  surveyor  and an  exceptional  surveyor. Field  Survey  Parties The size of a field survey party depends upon the  survey  requirements,  the  equipment  available, the  method  of  survey,  and  the  number  of personnel  needed  for  performing  the  different functions. Four   typical   field   survey   parties commonly  used  in  the  SEABEEs  are  briefly described in this section: a level party, a transit party,  a  stadia  party,  and  a  plane  table  party. LEVEL PARTY.— The smallest leveling party consists  of  two  persons:  an  instrumentman  and a rodman. This type of organization requires the instrumentman to act as note keeper. The party may  need  another  recorder  and  one  or  more  extra rodmen to improve the efficiency of the different leveling operations. The addition of the rodmen eliminates the waiting periods while one person moves  from  point  to  point,  and  the  addition  of a  recorder  allows  the  instrumentman  to  take readings as soon as the rodmen are in position. When leveling operations are run along with other control surveys, the leveling party may be organized   as   part   of   a   combined   party   with personnel assuming dual duties, as required by the work load and as designated by the party chief. TRANSIT PARTY.—  A  transit  party  consists of at least three people: an instrumentman, a head chainman,  and  a  party  chief.  The  party  chief  is usually the note keeper and may double as rear chainman,  or  there  may  be  an  additional  rear chainman.  The  instrumentman  operates  the transit;  the  head  chainman  measures  the  hori- zontal distances; and the party chief directs the survey and keeps the notes. STADIA  PARTY.—   A  stadia  party  should consist  of  three  people:  an  instrumentman,  a  note keeper,  and  a  rodman.  However,  two  rodmen should be used if there are long distances between observed points so that one can proceed to a new point, while the other is holding the rod on a point being observed. The note keeper records the data called off by the instrumentman and makes the sketches required. PLANE TABLE PARTY.—  The plane table party consists of three people: a topographer or plane table operator, a rodman, and a computer. The topographer is the chief of the party who sets  up,  levels,  and  orients  the  plane  table;  makes the  necessary  readings  for  the  determination  of horizontal  distances  and  elevations;  plots  the details  on  the  plane  table  sheet  as  the  work proceeds;  and  directs  the  other  members  of  the party. The rodman carries a stadia rod and holds it vertically at detail points and at critical terrain points  in  the  plotting  of  the  map.  An  inex- perienced   rodman   must   be   directed   by   the topographer to each point at which the rod is to be held. An experienced rodman will expedite the work  of  the  party  by  selecting  the  proper  rod positions and by returning at times to the plane table to draw in special details that he may have noticed. The  computer  reduces  stadia  readings  to horizontal and vertical distances and computes the ground elevation for rod observations. He carries and positions the umbrella to shade the plane table and  performs  other  duties  as  directed  by  the topographer. At times, the computer may be used as a second rodman, especially when the terrain is relatively flat and computations are mostly for leveling alone. Field Notes Field notes are the only record that is left after the field survey party departs the survey site. If these notes are not clear and complete, the field survey was of little value. It is therefore necessary that  your  field  notes  contain  a  complete  record of all of the measurements made during the survey and that they include, where necessary, sketches and narrations to clarify the notes. The following guidelines apply. LETTERING.—   All  field  notes  should  be lettered   legibly.   The   lettering   should   be   in freehand,  vertical  or  slanted  Gothic  style,  as illustrated in basic drafting. A fairly hard pencil or a mechanical lead holder with a 3H or 4H lead is  recommended.  Numerals  and  decimal  points should  be  legible  and  should  permit  only  one interpretation. 11-6