Every day it would search; if it found a PDF, it would download it and then it would run some PDF-scraping program, and out would come the text, and it would go on the Internet, and then people could make maps like that.
每天进行搜索，如果发现PDF文件， 就会下载下来， 然后它会运行PDF解码程序， 就可以将文本拷出来， 然后上传到网络上， 大家就可以做出这样的地图了。