ISES Empirical standard deviations for the image station
Columns | format | contents/explanation | |
|---|---|---|---|
1-4 | A4 | ISES | |
21-30 | F10.0 | sxST | standard deviations for centring accuracy on station XST |
51-60 | F10.0 | sΦ | standard deviations for measured photo orientations Φ, Ω, Κ |
This statement predefines standard deviations for following ISTA statements. In case of a value being zero, no observation equation will be established.
When applying forced-centring the accuracy for centring may be estimated as 0.2 - 0.6 mm. Values of up to 1 cm may be expected without forced-centring, depending on the quality of the points and on the auxiliary means (plumb bob, optical plumb).
When using photo theodolites, the standard deviations of measured photo orientations depend from the level indications and the precision of the instrument. In case of using IMU they depend from the respective accuracy and stability of the system.