beautypg.com

Surveying with true azimuths – Spectra Precision Survey Pro v4.5 Ranger User Manual User Manual

Page 81

background image

Conventional Fieldwork

71

Surveying with True Azimuths

Some people need to collect all of their horizontal angles in the form
of azimuths. Survey Pro can help automate this process by computing

the backsight azimuth after each new setup in a traverse and

updating the backsight circle and total station’s horizontal angle
accordingly.
1. You can setup on any existing point and use any other point in

the job as a backsight if the coordinate system is properly aligned
with true north. If not, you can occupy any point as long you have

a known azimuth to any reference.

2. In the Surveying Settings screen ( Job > Settings > Surveying ),

confirm that the Survey with True Azimuths checkbox is checked.

3. Setup the total station over the occupy point and aim it toward

your backsight.

4. Access the Backsight Setup screen; enter the Occupy Point, and

toggle the

.

BS Direction

.

/

.

BS Point

.

button to BS Direction

.

.

Note: When backsighting on a point, selecting BS Direction can still
be used, as described next, making it easier to view the azimuth to
the backsight.

5. If backsighting a known azimuth, enter it in the BS Direction

field. If backsighting a point, use the shortcut method to enter

the azimuth from the occupy point to the backsight point in the
BS Direction

field. For example, if you are occupying Point 1 and

backsighting Point 2, enter 1-2 in the BS Direction field. Once the
cursor leaves that field, the computed azimuth will replace what

you typed.

6. Tap the Circle… button, enter the backsight azimuth in the

Backsight Circle

field and tap Send to Instrument (or Set when

running in Manual Mode). This will set the backsight circle as

the horizontal angle in the total station and set the same angle as

the Backsight Circle value. This angle will then be subtracted
from all horizontal angles sent from the total station.