https://www.google.com/search?q=pilgrim+observer+model&sca_esv=abf976e12d8dcb8e&tbm=isch&sxsrf=ADLYWIIM5uqqopyzXF8RNpfYrpqyCdCzUA%3A1715275124492&source=hp&biw=1536&bih=703&ei=dAU9ZpuaHIPZkPIPoMukqAU&iflsig=AL9hbdgAAAAAZj0ThKJOaICn7H5oM5uBETbArEA-QLci&oq=pilgrim+ob&gs_lp=EgNpbWciCnBpbGdyaW0gb2IqA...