Choosing a target depth

You enter one target depth, in metres below the measurement line (the sensor), for the lines you select. Two properties of each line set which depths it can be asked for.

The shallowest depth: station spacing

Readings that are far apart cannot resolve a shallow source. The rule is:

station spacing ≤ 0.1 × target depth, so the shallowest target depth is ten times the station spacing.

The station spacing is the usual distance between neighbouring readings along the line. A refused line says the spacing and the shallowest depth it supports.

The deepest depth: line length

line length ≥ 3.2 × target depth, so the deepest target depth is the line length divided by 3.2.

The length that counts is the length of the piece of line processed (see gaps, below). A line can also be refused because no part of it is far enough from both ends for the depth asked; the answer is the same: a longer line or a shallower target depth.

Choosing

• Pick the depth you want to examine, between the two limits of every line you select.
• If some lines are refused, the reason names the limit; change the depth and press Check lines again, or leave those lines out.
• The depth you enter is the depth the job is set up for. The report states the depths it found; see Reading your results.

Gaps in a line

Missing readings are dropped, and gaps are never filled in. Lines with large gaps are processed in their longest unbroken piece; the report says which part of the line it covers. To have the other pieces processed, contact support.

Size limits

• At most 10,000 stations in one job. A longer line is refused with the number of stations it has. Split the line, or use a coarser spacing if your spacing is much finer than the target depth needs.
• A line can also be refused as larger than one job can process; split it into shorter lines and submit each one.
• Up to 60 lines in one selection.