a pair of observations

adjustment of indirect observations

aircraft（-based） observations

altitude observations of a celestial body

Borehole strainmeter observations

carrier observations

clinical observations

COMBINATION OBSERVATIONS

Conjugate observations

Constellation occultation observations

correlated observations

Curative effect observations

cytological observations

decoding observations

DISPLACEMENT OBSERVATIONS

Doppler weather radar observations

DOUBLE DIFFERENCE OBSERVATIONS

Dynamic observations

earth rock dam observations

empirical observations