This note documents the Epoch 3 background model files. Both the faint (L7_240) and bright (Sky_VLE) source background model files are available,

The names of the model files are

faint sources:
pca_bkgd_faintl7_e3v19990824.mdl
pca_bkgd_faint240_e3v19990909.mdl

bright sources:
pca_bkgd_skyvle_e3v19990916.mdl
pca_bkgd_allskyactiv_e3v19990917.mdl

Data from all the Epoch 3 background observations went into making these model files. Previously released model files were made from data accumulated during the first half of Epoch 3. Estimates of the systematic error are given for the faint source model.