Regional Jet 900 (CRJ900)
Air Traffic Control Developmental
Situational Awareness; Training / Qualification
ATC Issue All Types; Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert
Airspace Structure; Human Factors
After turning and descending the CRJ-900 I was dealing with a VFR south east of GPT that had traffic coming at him and didn't realize in time CRJ-900 hadn't turned as quickly as I anticipated and he was descending faster than I anticipated. In all honesty I remember him being higher than he was when I glanced back up at him. CRJ-900 was on the border of our antennas north of GPT 1780 highest obstruction where MVA is 3000 ft. His attitude when I saw was leaving 2900 ft. for 2800 ft. almost out of the MVA circle. No recommendations for the airspace I understand I just miscalculated the situation.
GPT TRACON Controller reported descending aircraft below the MVA.