Super typhoon Haiyan makes landfall
Super typhoon Haiyan
Subscribe here to receive special images


Lake Maggiore - Italy, 3-6 April 2000

VEGETATION Geometrical Image Quality

Sylvia SYLVANDER*, Patrice HENRY**, Christophe BASTIEN-THIRY** Frédérique MEUNIER**, Daniel FUSTER*
CNES, 18 avenue Edouard Belin, 31044 Toulouse
e_mail :

Paper (pdf file, 137 k)

The use of VEGETATION data for multidate applications needs severe geometrical specifications, especially for multitemporal registration. To comply with them, it was decided to improve the image location by a systematic use of ground control points. A ground control points (or GCP) data base was so generated through VEGETATION chips using space triangulation method. The current GCP data base used by the processing center CTIV is composed of about 3500 ground control points, regularly distributed on the globe. Their location accuracy is estimated to 100m RMS.

A monitoring of the geometrical performance has been processed and shows that the absolute location accuracy and the multispectral registration accuracy quite comply with the users requirements. In particular, the absolute location accuracy, estimated to 330m RMS, is very good. The multitemporal registration accuracy is also very good compared to the pixel resolution, but it is not fully complient with the users requirement.

In order to improve the multitemporal registration accuracy, several actions have been already carried out, in particular to try to increase the number of images corrected by GCP pointing: densification of the CTIV GCP data base, modifications of the CTIV GCP software, and so on


Geometrical image quality, absolute location accuracy, multitemporal registration, multispectral registration, space triangulation, Ground Control Points data base.