BeiDou Navigation Satellite System:

In 2007, the official Xinhua News Agency reported that the resolution of the BeiDou system was as high as 0.5 metres. With the existing user terminals it appears that the calibrated accuracy is 20m (100m, uncalibrated).

Please answer a question about this article. If the question is unanswerable, say "unanswerable". In 2007, what was the reported resolution of the BeiDou system?
as high as 0.5 metres