Leica TPS700 Series Field Manual - Surveying Equipment

Automatic Target Recognition (ATR)TCA and TCRA instruments aremotorized and equipped withAutomatic Target Recognition(ATR) coaxially in the telescope.The guide light (EGL), mountedon the telescope, is optional.These instruments permitautomatic angle and distancemeasurements to normal prismsand reduce the tedium of precisevisual sighting to prisms.The prism is sighted with theoptical sight only. Initiating adistance measurement will turnthe instrument with the help of themotors to sight the prism-centreautomatically.The angles V and Hz aremeasured to the centre of theprism completion of the distancemeasurement.As with all otherinstrument errors, thecollimation error of the automatictarget recognition (ATR) must beredetermined periodically (Referto chapter "Checking andAdjusting").Reflected light or lightfrom an outside source(e.g. head lights of a car) caninfluence ATR measurements.20