Figure 7. above: Four known benchmarks shown; MS60 was levelled on the PM 58000 pillar, below: The photo taken from the pillar PM 58001 (as Newcastle Test Baseline)

From

Updated Atmospheric Modelling of Refracted Zenith Angle Using Vertical Temperature Gradient for Refraction Coefficient

Mansoor Sabzali, Lloyd Pilgrim

Journal of Geosciences and Geomatics. 2023, 11(1), 11-20 doi:10.12691/jgg-11-1-2