Low Down

  Surface change such as vegetation acceleration or retardation as a consequence of ground disturbance can be seen from the air using conventional aerial photography; even single graves can be identified in some circumstances. Photographs are preferably taken at an oblique angle during clear weather when the sun is low in the sky (i.e., winter months, or summer mornings or evenings). Vegetation stress due to the proximity of decaying cadaver(s) can be seen using infrared photography, and heat emitted as a consequence of either insect infestation or putrefaction and autolysis can be detected using aerial thermal imagery, as can heat differentials between disturbed and undisturbed soils. Baseline data from which to observe more recent change can also be obtained by comparing pre-existing aerial photographs in any of the forms mentioned above (vertical or oblique, traditional, infra-red, or multispectral imagery), with those recently taken. In the U.K., complete coverage of air-photog...