Orientation (backsight) – Spectra Precision FAST Survey Reference Manual User Manual

Page 124

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icons to the right. You can also click the station and offset icon, as with the occupied point. A backsight point ID is

required, even if you choose to enter an azimuth or bearing only.

Backsight Bearing or Azimuth

: This displays the bearing or azimuth between the two entered points, when both

points have coordinates. If Angle Type, in Job Settings, is set to bearing, then a backsight bearing will appear. If

set to azimuth, then the backsight azimuth is shown. (Azimuth should always be used with a 400 circle/gons

configuration). When both point IDs have coordinates, the backsight is fixed and predetermined and therefore the

bearing/azimuth field is disabled since it cannot be altered. However, if the backsight point has no coordinates,

then you must enter a backsight bearing or azimuth, which will be used to calculate the null or zero coordinate point

ID.

Target Height

: This is the height in feet or meters (depending on your configuration) of the target, from ground

elevation to the center of the lens for example. Even if working in English units, you can enter a 2 meter target

height using 2m. This converts to 6.5617 feet automatically after you press Enter.

Note

: The backsight target height will default to the previous backsight target height on future setups. The

foresight target height is kept distinct and will default to previous foresight target heights, but will not

automatically match the backsight target height. If you prefer to survey by setting the prism pole to a fixed

height for both backsights and foresights, be aware that you will have to put in 2 initial target heights: one for

the first backsight in the backsight screen and one for the first foresight in the foresight screen, in order to get

both “remembered” values established.

Use Backsight Ht for Foresights:

This option will link the backsight height and the foresight height to

accommodate the use of a single prism for both the backsight and foresight readings, rather than a fixed tripod at

the backsight and roving pole scenario.

Confirm NEZ

: This option will display the full coordinates and description of both the setup and backsight points.

By default, the Setup coordinates will be displayed. You can tab to the backsight coordinates. Press Enter or tap
OK

to exit this dialog.

Configure

: This accesses the Configure screen for a variety of condition or settings changes (e.g. Hgt/Desc prompt

on save).

Backsight

: Continues to the Take Backsight screen.

OK or pressing Enter

: Continues straight to the Foresight screen. If OK is not highlighted and not ghosted,

pressing OK will still go to the Foresight screen, even if Enter does not.

Orientation (Backsight)

The backsight dialog has Setup and Results tabs showing the results of a measurement to the backsight.

Set Angle Option List:

There are three options for setting the reference angle in backsight. They are found in the

options list at the upper left of the Take BS screen:

Set to Zero

: This is the most commonly used option. A message is sent to the instrument to set it to zero, then

the backsight is taken at a zero reference angle. Angles are then typically turned to the right from zero.
Set to Backsight Azimuth:

In this scenario, the backsight direction in the gun is set to the azimuth of the

backsight. For example, if the backsight azimuth is 180 degrees, then an angle to the right of 10 degrees would

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