Scratching Sky surfer and Para plane
So I have checked sites about parafoils. A site tried a rebuilding a Hirobo paraplane that needs power much for loading a camera. It refers that a stick of the transmitter is unusual. Another site uses a Sky Surfer loading a camera^[1]. Hobby Zone describes the specifications of the Sky surfer. Hirobo site shows the specifications. I compared the both in the table. A site sells a parafoil kite ¥6,600. The size is 71cm��97cm. The maker is Premier Kites.

In searching RCG, I found 2 sites which makes parafoils and sell its kits and an excellent pilot. He rebuilt a Sky surfer.

Making parafoils

Parafoil kite

Two site write that it is diffcult to make a parafoil and costs $220. A labo of Kyushu Institute of Technology studies and made a parafoil of 1.5m span^[2]. Two students in Japan tried a test of a parafoil made by themselves. A blog shows a photo of the test. A site shows an example of scratch and how to make. The photo shows one of examples. However, it seems that the parafoil kite blows rather than flies. A labo does a wind tunnel experiment of a parafoil.

Check up parafoil for UAV project
I think that Parafoil has a characteristics of kite. A kite of 10 g/dm² needs winds of 10 m/s^[3]. Wing load of Sky surfer and Para plane are 25.7 and 134 g/dm². Their lift force are bigger than simple kite. But either value of Sky surfer or Para plane is not true, I think. I had bought Prairie L before. Its wing load is 40 g/dm². Para glider decends little at 5 to 10 m/s^[4]. Its speed is the same of bicycle. I hope my UAV will flies fast far away.

[1] link decay
[2] link decay
[3] Tako ga agaru genri
[4] Kuki rikigaku