The best times for prospecting
Although some would say otherwise, there is no way to precisely predict the best day (or days) for the appearance of the "ghosts of the past". At the very most, one can say that there are periods that are more or less favorable for the appearance of this or that type of clue to buried archaeological remains.
From January to April, when agricultural land has been laid bare by plowing, one can hope to discover soil anomalies, either when the ground is completely saturated with rain, or through hygrographic anomalies, due to residual dampness, particularly when the ground starts to dry. One should also take advantage of a blanket of snow, and contact the meteorological service, which can tell you if there is a chance of frost or dew in the morning. Very short-term local weather forecasts are crucial for aerial archaeology.
À Cocquerel (Somme), au lieu dit "Les Groseillers". Début juillet, des enclos circulaires de l'Âge du Bronze, repérés depuis longtemps dans les cultures.
En mars, même site sur sol nu qui commence à sécher. Aujourd'hui, ces cercles sont bien plus visibles et beaucoup d'autres détails apparaissent.
From late April to late July, des phytographic anomalies will become apparent as crops grow and mature, particularly in periods of drought, and especially when the drought occurs as the plants really start to push upwards and are most in need of water.
From the beginning of August until the end of the year, there is little chance of finding clues on the ground. Nevertheless, in October, the leaves turn beautiful colors, and this is the moment to photograph landscapes and topographic clues. Obviously, winter, when the sun is low on the horizon, creates shadows in pastures and wooded areas and thus highlights very low-relief features (skiagraphic clues)— although these images must be interpreted with caution.