Spectra Precision Survey Pro v5.4 - Manual (Page 77)

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A level loop can have two states: open or closed. Once a new loop is
created, it is automatically opened. It will remain open until you decide to
close the loop. A level loop is closed after shots are taken to the closing
CBM.
Level loops are stored within the current Survey file, which can contain any
number of level loops.
Any level loop can be selected from the current job as the active loop for
data collection. Once a loop is closed, it cannot be re-opened for data
collection. It can only be viewed or adjusted. Only closed loops can be
adjusted.
• A level turn represents the set of backsight-foresight observations collected
from a given location where your instrument is set up. Each level turn
calculates the elevation of the point in the loop for which the foresight
observation is made. A level loop typically consists of many level turns
between each level benchmark point stored.
• A benchmark is a point in your level loop for which you will store the
elevation as a point record in Survey Pro. A benchmark is usually a
permanent mark, such as a brass survey disk or a stable iron rod in the
ground, that can be reoccupied at a later date.
• A turning point is an intermediate point used to connect two benchmarks.
Because a level turn is usually short (typically less than 50 meters), many
turning points are often needed to make the connection between two
consecutive benchmarks.
As opposed to benchmarks, turning points are not permanent marks on the
ground and are not stored in the job. They only exist while the rod occupies
them during the foresight/backsight measurements.
• A sideshot point is a point of interest for which you will store the elevation
as a point record in Survey Pro. Unlike benchmarks, you do not turn
through sideshot points in the level loop, they are spur observations to the
loop.
• A stakeout point is like a sideshot point in that you do not turn through
these points. They are spurs to your loop. A stakeout point is used to display
the cut/fill information from the level observation and some design
elevation.