All the archaeological sites investigated by the Lochbrow Landscape Project are cropmark sites. Cropmarks are formed by the differential growth of crops over buried archaeology, and are best recorded from the air.
In the case of the sites at Lochbrow, the majority of the archaeological features have either been ploughed flat, and so all that remains are the infilled ditches of dug features such as barrows, or were built of wood, a material that is not durable and so does not survive for us to study today. All that is left of these wooden structures are the infilled pits that were dug to take the upright timbers forming the outer boundary of these wooden monuments. It is these pits or ditches that influence the formation of the cropmarks, allowing us to photograph them from the air.
Therefore, this is archaeology with few above-ground features; if you visit the site today there is little to suggest that such a complex of sites ever existed. Cropmark analysis, then, is the first stage of any study looking at sites such as those recorded at Lochbrow.
Cropmark analysis involves the close study of all the available aerial photographs. Those at Lochbrow have been recorded by RCAHMS aerial surveys. You can see some of the Lochbrow aerial photographs here on RCAHMS’ website. The next stage is the rectification (transformation of an oblique aerial photograph to a plan view) and mapping or transcription of the features. This was undertaken using the specialist software Aerial 5. The end result is a plan and interpretation of the cropmark features. This plan and the interpretations taken from the study of the aerial photographs form the basis for all subsequent work.