Non-linear least squares fitting in FPGA devices for digital spectroscopy

In measurement tasks, such as the determination of the arrival time of events, several methods based on least squares routines have been demonstrated. Nevertheless, the high potential of digital least squares methods in high-resolution nuclear spectroscopy is not fully exploited in practical due to its heavy calculation burden, especially in real-time applications and in spatial computing FPGA device implementation. The paper presents an efficient and real-time operating implementation into a Xilinx Virtex-5 SX50-SG-1 FPGA device of the Gauss-Newton algorithm, which is one of the most used methods to solve nonlinear least squares problems.