دانلود گزارش کارورزی و کار آموزی

چکیده : 

A method for precisely synchronizing an external serial data stream to the pulse-per-second (PPS) output

signal from global navigation satellite-based systems (GNSS) receiver is described in this paper. A signal

timing device was designed that used a digital signal processor (DSP) with serial inputs and input captures

to generate time-stamps based on an internal timer. All temporal measurements were made

directly in hardware, which eliminated any concerns of software latency. The resolution of the signal timing

device was 17.1 ls. Testing showed that time measurements made on the signal timing device were

consistent with measurements made using a digital oscilloscope. The standard error between the signal

timing device and digital oscilloscope was 47.2 ls which translated to less than a millimeter of horizontal

position error for agricultural operations at speeds less than 10 m/s. The signal timing device was shown

to be useful for synchronizing GNSS receivers with ground based position measurement systems used to

assess dynamic accuracy in agricultural applications by mitigating error due to latency.