1. A method for detecting edges of an object, the method comprising: producing from imagery an image of a scene including said object proximate a platform; computing horizontal image derivates of the image, wherein the horizontal image derivates are a rate of change in a gradient of the image; integrating column sums of the horizontal image derivatives to create an edge strength plot of the image; detecting peaks in the plot corresponding to dominant edges, wherein the dominant edges are potential pairs of left and right edges of the image; evaluating all the potential pairs of left and right edges of the image; and selecting the potential pair of left and right edges with maximum score, wherein the maximum score is a score with maximum integrated column sum value.