Is Baita Temple the same as the Baita in Beihai Park?

No, according to Baidu Encyclopedia, the White Pagoda of Baita Temple was built in the Yuan Dynasty, northeast of Fuchengmen Bridge in the West Second Ring Road, while the White Pagoda of Beihai Park was rebuilt in the eighth year of Qing Shunzhi (165 1) and is located on Qionghua Island. Beijing Baita Temple is the oldest and largest Lama Temple in China and the earliest Tibetan Buddhist pagoda in Beijing. It is considered as the oldest landmark building in Beijing.