Put the sheen's extent on the incident report.
An event-driven extent map for terminal HSE officers: the outline of the sheen, its area and the image it came from, on one dated sheet.
- GSD
- 0.5–2 m (High)
- Cadence
- Event driven
- Platform
- High-res satellite
- Spectral
- Multispectral
What the incident log holds an hour after the sighting
A sheen is reported near a berth. The duty marine supervisor notes the position and the time. The HSE officer takes the call, walks out to the jetty or goes out in the launch, and writes down how far it reaches and which way it is moving. Boom goes out where it looks to be heading. Then the report to the harbour authority or the regulator has to be filed, and the extent in it is an estimate made at water level: what could be seen from the quay, plus a few photographs taken at a low angle.
That estimate is hard to defend later. From the quay you see the near edge and lose the far one. Sun glint and cloud change how much of the sheen is visible from minute to minute. The person who wrote the figure may be off shift when the regulator asks how it was drawn. The incident log ends up with a number and no picture behind it.
An image taken from above shows the film's reach in one frame, where it is visible, with a date and time on it. This page sells that picture, outlined and measured, as an addition to what your people already record.
Key
- Sun glint
- Spectral contrast
- Sheen outline
What is on the sheet
- 2.1
Sheen outlineVector outline
The edge of the sheen drawn on the source frame and supplied as a file your GIS or chart software opens. One outline per event and per pass.
- 2.2
Estimated extentArea
The water area inside the outline, stated as an area. It is surface extent only. It says nothing about how much oil is in the water.
- 2.3
Source frameImage reference
The image the outline was drawn from, with its acquisition date and time, so whoever reads the report can see what we saw.
- 2.4
Dated sheetSheet, PDF
The outline, the area and the source frame on one page with the event details, ready to attach to an incident report or file in the environmental incident log.
Between them, these four items are a record of one event. On a pilot, the sheets cover events at the terminal you name.
How it works
- 3.1
Report the event
Tell us the terminal, the berth or mooring, and when the sheen was seen. A sketch of your own position estimate helps us check the outline against what your people saw.
- 3.2
Imagery is tasked
We request the next available daylight pass over the terminal. The wait depends on the satellite schedule and the sky.
- 3.3
The sheen is mapped
The outline is drawn from sun glint and spectral contrast in the image. Where the two disagree, or where the image cannot support an outline, the sheet says so.
- 3.4
The sheet comes back
You get the outline file and the dated sheet. You attach the sheet to your report; the report and what it says remain yours.
Where it fits in your workflow
Beside the quay-side estimate
Keep your supervisor's position and time, and the launch's observations. The sheet is a second, independent read of how far the sheen reached, filed with them. It sits in the incident log next to the boom deployment notes, and it gives a regulator or harbour authority something to check your estimate against.
For the response record
After the event, the sheet documents what the sheen looked like at one moment from above. If the film has broken up or gone by the time the pass arrives, the sheet records that too, which is useful to the record.
Limits
- L1
Daylight and sun geometry
Detection reads sun glint and spectral contrast in daylight. Nothing is mapped at night, and low sun or a flat, glint-free sea can hide a sheen that is there.
- L2
Cloud
A cloudy sky blocks the image. If the tasking window is overcast, the pass is lost and the next window is used.
- L3
Timing is a target
The pass is event-driven and depends on the next tasking window. A sheen can move, break up or weather away before the image is taken. We tell you when you report an event what the window looks like; we do not promise it.
- L4
Resolution floor
Pixels are between 0.5 and 2 m across. A thin sheen pressed against a hull or along a quay wall can be narrower than a pixel, and the outline will miss it. Very small sheens are not resolved.
- L5
Other dark patches
Some things on the water look like a sheen from above: calm patches, algae, a wind shadow. The sheet flags these where the image gives us a reason, and cannot always tell them apart from oil.
- L6
Extent only
The sheet does not name the source of a sheen, the vessel or party responsible, or the quantity of oil. Area is not volume, and the sheet reports area alone.
Who it's for
For
- Terminal HSE officers and environmental officers who write the incident report after a sheen at a berth or mooring.
- Terminal and port operators who want an independent extent read in the incident log.
- Regulators or harbour authorities reviewing a reported sheen near a terminal.
Not for
- Buyers who need the source of a sheen or the party responsible identified.
- Volume or barrel estimates; the sheet gives area only.
- Night-time or through-cloud detection.
- Continuous watch of a harbour; it responds to a reported event.
- A certified or regulator-approved record; the sheet is supporting evidence for your own report.
Questions before a pilot
Does this identify who caused the sheen?
No. It maps where the sheen is and how large it is. It says nothing about the source or the responsible party.
Can it estimate how much oil is on the water?
No. Surface extent is not a reliable proxy for volume, so the sheet reports area and stops there.
Does it work at night or through cloud?
No. It needs daylight and a clear enough sky for sun glint and spectral contrast to show up in the image. An overcast window is lost, and we use the next one.
How soon after an event can you get a pass?
It is event-driven and depends on the next tasking window over your terminal. Give us the location and the time of the sighting when you report, and we will say what the window looks like. The pass may come after the sheen has moved.
Is the sheet accepted by the regulator?
We make no claim on that. The sheet is supporting evidence you attach to your own report. Whether a regulator or harbour authority takes it is their decision, so ask them before you rely on it.
How do we check it against what our people saw?
Compare the outline with the position and time your supervisor and launch recorded. On a pilot, tell us what you recorded only after the sheet has been delivered, and judge for yourself whether the outline is good enough for your log.
What format does it arrive in?
An outline file your GIS or chart software can open, and a dated sheet you can attach to a report. We do not write into your incident log or reporting system.
Who owns the sheet and the imagery?
Ownership and licence terms for the sheets and the underlying imagery are written into the pilot agreement before anything is ordered. If your legal team needs to review them, ask early.
How is a pilot bought and priced?
The quote depends on the terminal and how many events the pilot covers, and we price it for yours. Tell us how your company buys.
Report an event, get a sheet.
Tell us the terminal and berth you would put in a pilot, and how your reporting process runs. We will tell you straight whether the imagery can work for it.
Start a pilot