Objectives of astronomical observations in surveying In field astronomy applied to surveying and geodesy, which of the following quantities are typically determined from observations?

Introduction / Context:
Astronomical methods provide absolute orientation and positioning independent of ground control networks. Surveyors use celestial observations to determine latitude, longitude, and azimuth, which underpin triangulation, traverse adjustments, and calibration of instrument orientation.

Given Data / Assumptions:

• Observations include altitudes and azimuths of stars or the sun.
• Time is known or simultaneously determined via astronomical methods.
• Corrections for refraction and instrument errors are applied.

Concept / Approach:
Latitude is obtained from meridian altitudes or circumpolar star observations. Longitude derives from precise time comparisons between local apparent time and a standard meridian. Astronomical bearing (true azimuth) is deduced from observed azimuths of known celestial objects at recorded times.

Step-by-Step Solution:
Measure star/sun position and time.Reduce observations for refraction and instrumental errors.Compute latitude, longitude, and azimuth using spherical astronomy relations.Cross-check with known control when available.

Verification / Alternative check:
Redundant observations to multiple stars across the sky improve precision; closure checks on azimuth help validate results.

Why Other Options Are Wrong:
Each of (a)–(c) is a legitimate objective; the comprehensive answer is “All of these”.

Common Pitfalls:
Neglecting time accuracy; longitude determination is highly sensitive to errors in observed or chronometer time.

Final Answer:
All of these