Measurement Units

A/AB = Degrees/Mils/Grads

Establishes the default angle units for the azimuths in compass and tape (CT) data lines. The second form (e.g., "AB=D") specifies the units for the backsight instrument. The initial default is decimal degrees.  The current default can be overridden for individual measurements with D, M, or G suffixes (upper or lower case), with quadrant-style bearings, or with DMS entries like 135:10:30.  For example, when A=D is in effect, 90 degrees azimuth can entered as 90, 1600m, 100g, N90E (or E).  On CT data lines, backsights are indicated with a slash (/) prefix immediately following the foresight (if one is present).  See Vector Data Lines.

D = Meters/Feet

S = Meters/Feet

Meters/Feet

The first form (D=...) establishes the default distance units for both compass and tape (CT) and RECT data lines.  The coordinates of #FIX directives are also assumed to have these units.  The second form (S=...) specifies the units for instrument/target heights above station and any LRUD measurements on CT data lines.  The third form (Meters or Feet) is a shorthand way of specifying the default units of all length quantities -- both distances and heights. The initial default in each case is meters.

When there are more than one type of length quantity on a data line (shot distance, height measurements, relative variance, LRUD distances), you may have to override the current units of specific measurements with the suffix "m" or "f" (upper or lower case), or with the inches designator, "i".  Such formats also allow you to enter a few exceptional data lines without having to bracket them with #Units directives. See Overriding Default Units with Special Formats.

When units are specified as feet, the program assumes International foot units, where a foot is exactly 0.3048 meters, not U. S. Survey foot units, where a foot is approximately 0.3048006 meters. Such a distinction would be important if for some reason you need to express UTM coordinates in feet.

V/VB = Degrees/Mils/Grads/Percent

Establishes the default angle units for the vertical angles (inclinations) in compass and tape (CT) data lines. The second form ("VB=") specifies the units for the backsight instrument. The initial default is decimal degrees.  The current default can be overridden for individual measurements via a D, M, G, or P suffix (upper or lower case), or by using the DMS format for degrees, minutes, and seconds (ddd:mm:ss).  Note that the "right side" scale in some clinometers (Suuntos) is percentage grade, with +100 percent corresponding to +45 degrees (grade being interpreted as the tangent of the angle).  Like azimuth backsights, back-inclinations are indicated with a slash (/) prefix immediately following the foresight (if one is present).  See Vector Data Lines.