HD-MAX Echo Sounder User Guide
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Height fitting is parameter correction to elevation fitting. Generally, it is
jointly used together with plane transformation parameters. The
frequently-used Polynomial fitting parameters include: Geometric Surface,
TGO, Grid, FreeSurvey Height fitting, and elevation fitting pattern
description etc.
Figure 7-11 Elevation fitting model
According to the fitting method selected, generally select "Constant" of "
Geometric Surface". Equations are obtained through inputting parameters or
elevation fitting algorithm of [UtilityTools], such as parameter fitting and
plane fitting:
Figure 7-12 Fixed difference correction
Description of several commonly used elevation fitting parameters:
(1) Geometric Surface
Constant correction: Take GPS measured elevation and the fixed constant as
operational elevation. Only a starting point is required.
Plane fitting: An optimal fitting plane will be generated corresponding to
height anomaly at multiple benchmarks based on three starting points. When
the plan is parallel to horizontal plane, the plane fitting is equal to fixed
difference correction.
