Use in City Mapping
In city mapping, even though time be taken to establish a very elaborate system of controls, the air camera can accomplish in a few hours a task of years by ordinary methods. In fact it is only by means of air photographs that maps of a growing city can be kept at all up to date. Paris was mapped with 800 plates in less than one day of actual flying. Washington was completely mapped in two and a half hours with less than 200 exposures.[10] For the mosaic of Rochester, N. Y. (Fig. 56) 82 photographs were made in one hour and twenty minutes. There is no reason why such a mosaic with an original survey or even a number of accurately located points as a basis of control should not be sufficiently accurate for all purposes.