Updating Large Scale Topographic Databases in Italian Urban Areas with Submeter QuickBird Images

Table 1

Accuracy of the orthoimages generated using the rational function model and the spline interpolation methods, calculated on the basis of 30 independent check points.

Method	GCPs	RMSE (m)
	(nr.)	East	North	Overall
	40	0.62	2.14	2.22
	50	0.58	1.41	1.52
RFM	60	0.55	1.11	1.24
	70	0.51	1.12	1.23
	80	0.50	1.10	1.21
	40	0.60	1.55	1.66
	50	0.55	1.45	1.55
Spline	60	0.61	1.49	1.61
	70	0.60	1.50	1.61
	80	0.57	1.51	1.62