Here is all of the pokeradar pokemon you can find here in pokemon diamond.
Note: This is slightly different from the ones in Pokemon Pearl.
Mightyena: Route 214 + 215
Larvitar: Route 207
Mareep: Valley Windworks
Nidoran Female + Male: Route 201
Venonat: Route 229
Mankey: Route 225 +226
Grimer: Route 212
Ditto: Route 218
Sentret: Route 202
Togepi: Route 230
Hoppip: Route 205
Sunkern: Route 204 North
Wobbuffet: The Three Lakes
Smeargle: Route 212 North
Tyrogue: Route 208 + 211 West
Miltank: Route 209 + 210 South
Swellow: Route 213
Ralts: Route 203 +204 South
Nincada: Eterna Forest
Loudred: Mount Coronet Top
Aron: Fuego Ironworks
Torkoal: Route 227 + Stark Mountain
Trapinch: Route 228
Swablu: Route 211 East
Baltoy: Route 206
Kecleon: Route 210 North
Duskull: Route 224
Snorunt: Route 216 +217, Lake Acuity Surroundings
