Opencast Survey Handover: What the Planning Team Needs

Opencast survey handover problems rarely come from the figures themselves. On opencast mining surveys, they come from the information that should have travelled with the figures and did not, which is why the planning team keeps asking the same follow-up questions.

This article is specific to opencast work feeding a mine planning system. The general evidence that should arrive with any survey is covered in our survey handover checklist.

What an opencast survey handover must state

An opencast survey handover must carry seven items alongside the figures, and each one answers a question the planning team would otherwise have to ask.

Date and extent travel with every figure

A volume or face-position figure is tied to the date and extent of the survey that produced it. Mining continues after the survey, so a figure used without those two facts risks being applied to ground that has since changed. Put the date and extent on the drawing, in the file name and in the covering note, so they cannot be separated from the figure.

Where the handover combines surveys captured on different days, state the date for each part. A single date on a combined surface hides the fact that some of it is older than the rest.

Reference frame, datum and control

Name the coordinate reference frame in words and by its code in the EPSG registry, state the height datum, and list the control stations used. A surface on the wrong reference will import and sit in the wrong place, which is harder to spot than a file that fails outright.

What was not captured

State any area that could not be reached or was excluded on the day. Without that note, a gap in the surface looks like empty ground, and the planning team may design over it. A short line in the handover prevents a wrong assumption that is expensive to find later.

Making the handover import first time

A handover intended for a mine planning system is only usable there if its format, reference frame and control basis match what that system expects.

Agree the format once

Ask the planning team which surface format and version their software opens, and which layer or naming conventions they use. Write that down and attach it to every survey request. Aerial and ground capture can both deliver to the same format; our article on drone survey deliverables covers the files an aerial survey should return.

Test the first delivery

Import the first handover under the new list while the surveyor is still available. Any mismatch found then is a quick fix: a format setting, a layer name or a reference code. Check that the surface lands where the previous one did, not only that the file opens. Found three months later, it can undermine every comparison made in between.

Keep the list the same across surveys

On pits with monthly measurement, the same list should apply to the pit surfaces, stockpile surveys and any volumetric work, so every surface lands in the same place in the planning model.

Keep a copy of the agreed list with the survey contract as well as with the planning team. When a surveyor changes, or a new person joins either team, the list carries the agreement forward. An opencast survey handover that follows a written list does not depend on anyone remembering what was agreed.

Where survey cannot help you

A complete handover makes survey data usable in planning, but some decisions sit outside what any survey delivery can settle.

A survey cannot keep a figure current once mining has moved on. It cannot choose the planning software's settings, and it cannot decide whether a figure is recent enough for a particular decision. That judgement belongs to the planning team, and the date and extent on every figure are what let them make it. The survey's job is to make those facts impossible to miss. Where an older figure is about to drive a materially later decision, re-survey first. Stating the date and extent reduces the risk of using an old figure. It does not remove it.