Triangulation terminology — station with no direct observations In a triangulation series, what is the station called where no angles are actually observed, yet the station is included in computations using adjoining observed angles?

Introduction / Context:
Triangulation networks use a hierarchy of stations: main, subsidiary/satellite, and sometimes computed points used for geometric continuity. Understanding the roles and naming conventions helps in reading specifications and processing angle observations correctly.

Given Data / Assumptions:

• A triangulation series where some stations may not be occupied for angle measurement.
• Classical nomenclature from geodetic surveying texts.

Concept / Approach:
A main station is fully observed and forms the backbone of a series. Subsidiary or satellite stations are auxiliary, often established near a main station to avoid obstacles or to observe specific lines. A pivot station (also termed “station of no observations” in many texts) is included in the series for geometric continuity, but no angles are directly measured there; instead, the adjoining observed angles at other occupied stations define the geometry through it.

Step-by-Step Solution:

Verification / Alternative check:
Adjustment descriptions often list stations of no observations and constrain them via observed sides/angles from adjacent occupied stations, confirming the usage of “pivot” terminology.

Why Other Options Are Wrong:

• Satellite and subsidiary stations are established for observation, usually near a main station.
• Main station is an observed principal point of the network.
• “None of these” is incorrect since a standard name exists.

Common Pitfalls:
Assuming every named station must be occupied; misunderstanding that some stations are computed for closure and geometry without direct angular observations.

Final Answer:
Pivot station (station of no observations)