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First order water crossing surveys

Since 2011 Starmountain Survey & Consultancy added a new product to their portfolio; first order water crossing surveys. In preceding years water crossing surveys were already an integral part of the bridge measurements, but at a second order level.

In cooperation with the Dutch governmental survey department this new product was developed in 2011, which combines mid 20th century instruments with contemporary technology.
An 1800 metres centered water crossing survey set-up with two Wild N3's
A Wild N3 with digital camera attachmentThis new method uses digital camera's, newly developed INVAR barcode levelling rods and in-house built software. Thanks to this combination the observations are objective and highly automated, with an accuracy not shown before of approximately 0.5√L[km] millimetres. At short distance the system can even be used for (sub)micrometer measurements, ideally for deformation measurements.

The results of the survey are available about 10 minutes after the survey was finished. The largest water crossing measured so far of 1,800 metres had a proven closing error of only 0.7 millimetres.