Abstract: A convergence model is shown and described for accommodating variation in data post spacing in a digital terrain elevation database (DTED) based on longitude and latitude address values for data posts. Under such a database structure, data posts lying along lines of latitude vary in spacing according to latitude, and converge at the poles with zero spacing therebetween. To scan a circular region of data posts relative to a given data post, e.g., a threat installation, this variation in data post spacing is considered by appropriately scaling sample step spacing along radials traversed in executing a radial spoke scan pattern. In this manner, a circular region of data posts surrounding a given data post may be sampled using simple, dedicated hardware despite this variation in data post spacing.