Question: how to calculate vdp on approach?
Answer: You can calculate your own visual descent point (VDP), since one isn't provided for you, by taking the height above touchdown (600 ft. in this case) and dividing it by 300 ft/NM. This gives you 2.0 miles from the runway. Since the chart shows the runway threshold at 0.2 DME, your VDP will be at 2.2 DME.