Stop timing the weather to find cropmarks.

Buried Feature Detection reads near-infrared imagery over your survey area in the growing season and flags the crop patterns that can mark buried walls, ditches and palaeochannels. You get a map layer for the desk-based assessment instead of a folder of aerial photographs to squint at.

Get startedSee the comparison
GSD
≤0.5 m (VHR)
Spectral
RGB + NIR
Platform
VHR satellite / aerial
Cadence
Seasonal window
Section through a field: the crop grows taller over a buried ditch and ripens early over a buried wall. TALLER CROP OVER DITCH FILLCROP RIPENS EARLY OVER WALLDITCH FILLWALLGROUND LINE Section through a field: the crop grows taller over a buried ditch and ripens early over a buried wall. TALLER CROPRIPENS EARLYDITCH FILLWALL
FIG. 0Section through a growing crop. Not to scale.

Where the desk-based assessment runs out

You open the HER and the old photographs for the site. Some fields have good cropmark coverage and some have none, because a flight only caught a dry spell over the ones somebody happened to fly. So you watch the forecast, wait for the crops to show stress, and send someone out before the marks fade. Miss the window and the site waits a year.

Then the anomalies you do find get redrawn by hand into the GIS, and the DBA goes out with a geophysics plan built partly on a hunch.

Ripe barley in a field, with a band of greener barley running across it
FIG. 1Barley at the end of the growing season.

Your DBA routine, step by step

No.StepTodayWith Buried Feature Detection≤0.5 m (VHR) · RGB + NIR · VHR satellite / aerial · Seasonal window
01Timing the lookYou watch the weather and the crops, then book a flight or send someone to walk the field when the stress looks right. If the window is missed, the site waits a year.We read NIR imagery over your survey area across the growth window and tell you which passes were usable.
Still yoursDeciding when the project needs its answer.
02Coverage of the survey areaYou rely on whatever aerial photographs the archive holds, taken on other people's flights in other years, so coverage of your fields is uneven.One consistent read over the whole boundary, every pass dated.
03Finding the marksSomeone looks at the photographs by eye and transcribes what they think they see.The imagery is read for differential growth against the surrounding field, and candidate anomalies are flagged on a layer with a confidence note each.
Still yoursJudging which flags are worth following up.
04Clean pass or inconclusiveA set of photographs with nothing obvious on them is ambiguous. No marks could mean no features or the wrong weather.Each pass is reported as usable or inconclusive, so a clear sky and the wrong crop stage is not read as an empty field.
05Getting it into the DBAMarks are redrawn by hand into the GIS and the figures.A georeferenced layer and a rendered overlay, with source imagery dates attached. Drag the layer into QGIS or put the overlay in the appendix.
06Where the magnetometer walksGeophysical survey is planned across the whole area or by hunch.The layer shows where the crop is already pointing, so you can walk those places first.
Still yoursThe geophysical survey, the trial trenching, and every interpretation of what a feature is.

What comes back

  1. Cropmark layer

    GeoJSON

    A georeferenced layer of flagged anomalies over your survey area. It opens in QGIS and ArcGIS. Serves the "finding the marks" row.

    Schedule row 03, Finding the marks

  2. Flagged feature list

    List with confidence notes

    Each flagged anomaly with a note on how confident the read is, for checking against your HER and geophysics. Serves the same row.

    Schedule row 03, Finding the marks

  3. Rendered overlay

    Image for the report

    The layer drawn over the source imagery, ready to place in your DBA appendix. Serves "getting it into the DBA".

    Schedule row 05, Getting it into the DBA

  4. Source imagery dates

    Attached to every pass

    The dates of the imagery behind each result, and whether the pass was usable or inconclusive.

    Schedule row 04, Clean pass or inconclusive

  5. Seasonal refresh

    Each growing season

    A new layer each growing season while conditions hold. On a site you revisit, compare one season to the next.

    Schedule row 01, Timing the look

How it works

  1. Before the season

    Send the survey area

    You send the boundary of the survey area, with the season you are scoping for. Do it early in the year, well ahead of the growth window.

  2. During the growth window

    The imagery

    We collect NIR imagery over the boundary while the crop is growing. Optical imagery needs clear sky, so some passes won't be usable, and we say which.

  3. After the pass

    The read

    The imagery is read for differential growth against the surrounding field. Anomalies go on the layer with a confidence note, and the source imagery dates go with them.

  4. Before the DBA is signed off

    Delivery

    The layer, the list and the overlay come back for the assessment and to shape the geophysics plan. On a later visit we refresh it.

Limits

  1. What crop stress is

    This reads vegetation, not soil. Nothing shows unless the crop is stressed, and that depends on the crop, the soil and the weather. We never guarantee a mark will appear in a given season.

  2. Clear sky and crop stage

    Optical passes need clear sky and the right crop stage. A cloudy or off-season pass returns nothing usable, and we report it as inconclusive. It never means there is no feature.

  3. Resolution

    At 0.5 m a pixel is wider than a hairline crack or a post-hole. A linear pattern across the field is what the layer can pick up. Small single features won't be traced.

  4. Anomalies, not identifications

    A flag says something odd is going on in the crop. Whether it is a wall or a ditch is a hypothesis, and how old it is cannot be told from imagery.

  5. Screening layer

    This sits ahead of geophysical survey and trial trenching. It narrows where they go. It does not replace either.

Who it's for

Switch if you are

  • A field director scoping a desk-based assessment before a dig season.
  • A unit that currently leans on archive photographs and weather luck for cropmark evidence.
  • Planning geophysics and want a first-pass layer to narrow where it walks.

Stick with your current routine if you are

  • Expecting a layer that identifies or dates features.
  • Working on land where there is no growing crop, such as built-up or bare ground.
  • Looking to skip geophysical survey or trial trenching.

Questions before you start

Does this replace geophysical survey?

No. It is a first-pass screen, and geophysics and trenching still do the checking. Use it to decide where they go.

What if the season is wrong for cropmarks?

Then little shows, because crop stress needs the right soil and weather. We flag each pass as usable or inconclusive, so a quiet season isn't read as an empty site.

How do we check it against what we already know?

Lay the layer over your HER records and any earlier geophysics for a site you know well, and see whether it finds what your own people found. Do it before you rely on it for a new one.

Can you tell us what a feature is, or how old?

No. The layer locates candidate anomalies. Interpreting them is the field director's job, and dating needs the ground.

What resolution does the imagery have?

VHR at 0.5 m or finer, with RGB and NIR bands. That suits linear patterns such as ditches and wall lines, not single small features.

Does cloud cover delay a pass?

Yes. Optical imagery needs clear sky, and we report which passes were usable.

Which formats do we receive?

A GeoJSON layer that opens in QGIS and ArcGIS, a list of flagged features, and a rendered overlay for the report.

Who owns the layer and the imagery?

Ownership and licence terms are agreed before the work starts, including what may be published in a DBA or a report. If your legal team wants to read them first, ask early.

How is it priced?

We price it for your boundary and do not quote a price on this page. Send the survey area and we will come back to you.

A ripening cereal field under a grey sky, with a line of trees beyond

Scope the season before you book the dig.

Send us the survey area and the season you are planning for. We will tell you whether the imagery window can serve your DBA.

Get started