Not quite the same thing, although they do have some similarities.
The Selective Availability "feature" of GPS worked by fuzzing the time readings output by the GPS satellites. The fuzz was time-varying but only changed every few seconds. Because it affected nearby receivers with similar amounts of error, if you had access to two receivers in the same area you could quite accurately measure their positions relative to each other.
The Chinese map obfuscation scheme is basically a secret map projection (it's not a constant offset, it varies over locations). GPS coordinates go into a black box and out come obfuscated coordinates, which you then use to plot on the map. Because there wouldn't be much point to GPS receivers that constantly show your location on the wrong point on the map, receivers sold in China actually incorporate the algorithm, and it probably wouldn't be too difficult to reverse engineer.
I'm trying to figure out if you are serious about "Chinese Map Obfuscation Schemes". Your description of SA and DGPS is spot on, but I can't think of any reason that China would want to obfuscate their maps now that satellites have mapped their country.
The Selective Availability "feature" of GPS worked by fuzzing the time readings output by the GPS satellites. The fuzz was time-varying but only changed every few seconds. Because it affected nearby receivers with similar amounts of error, if you had access to two receivers in the same area you could quite accurately measure their positions relative to each other.
The Chinese map obfuscation scheme is basically a secret map projection (it's not a constant offset, it varies over locations). GPS coordinates go into a black box and out come obfuscated coordinates, which you then use to plot on the map. Because there wouldn't be much point to GPS receivers that constantly show your location on the wrong point on the map, receivers sold in China actually incorporate the algorithm, and it probably wouldn't be too difficult to reverse engineer.