Which of the following statements is/are correct in relation to modern surveying instruments?

1. A total station is a combination of an electronic theodolite and a tachometer.

2. A smart station is a total station with a GPS rover unit.

3. Tellurometer is a short-range equipment with a range of up to 3 km.

Explanation:

Statement 1: A total station is a combination of an electronic theodolite and a tachometer.

Correct.
A total station is an instrument that integrates:

• Electronic Theodolite (for measuring angles)

• Electronic Distance Measurement (EDM) device (for measuring distances)

• Microprocessor (for calculations and data storage)

Note: The term "tachometer" here refers to tachymetry, which is rapid surveying involving distance and elevation measurements — functions handled by EDM in total stations. So the statement is essentially correct.

Statement 2: A smart station is a total station with a GPS rover unit.
Correct.
A smart station integrates:

A total station, and

A GNSS/GPS rover unit, allowing it to work without needing a known station point.
It helps in surveying from any location by combining angle, distance, and GPS positioning.

Statement 3: Tellurometer is a short-range equipment with a range of up to 3 km.

Incorrect.
The tellurometer is a microwave EDM device used for long-distance measurements.

• It can measure distances up to 100 km or more under ideal conditions.

• It was one of the first EDM instruments developed (1950s).