Topcon (Netherlands)

Multi-facility GNSS antenna calibration

Abstract Accurate antenna calibrations are a cornerstone of high-quality global navigation satellite systems (GNSS) positioning, time and frequency transfer, precise orbits, and troposphere estimates. The international GNSS service (IGS) antenna committee maintains antenna phase...

Twin reversed arterial perfusion (TRAP) sequence in a low – resource setting: a case report from South Sudan

Twin reversed arterial perfusion (TRAP) sequence, also known as acardiac twinning, is a rare complication unique to monochorionic twin pregnancies in which a structurally normal “pump” twin supplies circulation to a severely malformed, non-viable “acardiac” twin through abnormal...