Glad to see this report being referenced. A friend and I volunteered to gather this data at the beginning of 2017 along with hundreds of other volunteers. It's an interesting process. You show up, they assign you specific streets to walk and you just count up homeless people, noting their sex, rough age, and dwelling type (improvised structure, vehicle, etc.).

I encourage anyone who is interested to volunteer for the next SF homelessness count, likely in January 2019 (They do one every 2 years).