In order to have a high level of accuracy of measurement in underwater close-range photogrammetry, this article deals
with a study of three varieties of model equations according to the way of imaging upon the water. First, the paper makes
a careful analysis for the two varieties of theoretical equations and finds out that there are some serious limitations in
practical application and has an in-depth study for the third model equation. Second, one special project for this
measurement has designed correspondingly. Finally, one rigid antenna has been tested by underwater photogrammetry.
The experimental results show that the precision of 3D coordinates measurement is 0.94mm, which validates the
availability and operability in practical application with this third equation. It can satisfy the measurement requirements
of refraction correction, improving levels of accuracy of underwater close-range photogrammetry, as well as strong antijamming