From Bulbapedia, the community-driven Pokémon encyclopedia.
The Poké Radar (Japanese: ポケモントレーサー Pokémon Tracer, ポケトレ Poké Trace for short) is a key item in Generation IV that is used to seek out wild Pokémon hiding in tall grass.
In Diamond, Pearl, and Platinum
After the player has seen every Pokémon in the Sinnoh Pokédex, they will be able to meet Professor Oak in Professor Rowan's lab in Sandgem Town. After Oak upgrades the Pokédex to the National model, Rowan will give the player the Poké Radar but will not explain it very thoroughly. In Pokémon Platinum the opposite-gender rival, Dawn or Lucas, do however - when spoken to they give a practical demonstration on Route 202 if the player has received an Eevee from Bebe in Hearthome City. When the Poké Radar chain has reached 40, (as seen on Pokétch App 20#) the player can reset the chain and a patch of grass may sparkle. Once the player starts a battle in that patch of grass, the Pokémon will be Shiny.
It can only be used in the standard tall grass, while on foot, at which point a tune will begin to play, and one or more patches of the long grass may begin to move. Patches that shake more violently than others are often rarer Pokémon; some Pokémon can only be found using the Poké Radar. When a player walks into one of these moving patches, a battle with a wild Pokémon will instantly begin. Roaming Pokémon cannot be encountered while using the Poké Radar. Like the Vs. Seeker, the Radar's battery must be charged after use by walking around. It takes fifty steps to fully charge the Poké Radar. It is possible for the Poké Radar to find no wild Pokémon, in which case the message "The grassy patch remained silent..." will be displayed.
The formula for the probability of finding a Shiny Pokémon. Nc is the number of Pokémon in the chain, up to 40. The chances are calculated so that any Pokémon caught past a chain of 40 has a 1 in 200 probability of being Shiny.
If the Pokémon that is found is knocked out or captured in a Poké Ball, a chain will begin. These chains consist of multiple members of the same Pokémon species encountered one after another. The only catch is this: a player must not encounter any Pokémon just by walking through non-wiggling grass, only by walking into the grass that shakes. Therefore, it is recommended that Repel is used in order to ensure this and achieve a higher chain. Entering the patch of shaking grass that is the farthest away from the previous patch of grass increases the chances of meeting the same kind of Pokémon consecutively. Long chains increase the chance of finding a Shiny Pokémon, which is indicated by the patch of grass glowing white twice rather than shaking. Though rare, it is possible to encounter a Shiny Pokémon in a regular shaking patch. If, in the middle of a chain, a Pokémon ceases to become available (such as a swarming Pokémon), that Pokémon will continue to be available until the chain is broken.
One of the many functions of the Pokétch is to display the current chain and the three best chains made so far.
List of Radar-exclusive Pokémon
In HeartGold and SoulSilver
- Main article: Pokéwalker
On the Pokéwalker that is bundled with Pokémon HeartGold and SoulSilver Versions there is a primitive version of the Poké Radar, which costs 10 Watts to use. In this Poké Radar, there are four patches of grass, one of which will display a '!' which indicates the presence of a wild Pokémon (or a '!!' or '!!!' depending on the Pokémon's rarity). As with chaining in the main series games, chaining is also possible in the Pokéwalker, but it is dependent on timing and the amount of steps taken. If the player waits a while after a '!' appears and click it, there is a chance that he/she may get another '!' patch, over-riding the previous one. If the player continues this trend he/she will get a '!!' patch , and then a '!!!' patch after that. The timing needed to wait seems to vary between the rarity of the Pokémon, with rarer Pokémon needing less time.
In the TCG
The following is a list of cards named Poké Radar.
On Bulbagarden forums