Speaker
Description
The AgraSim experiment at Forschungszentrum Jülich is a unique laboratory for research on the impact of climate conditions on agricultural ecosystems and for the optimization of climate models. For the high-resolution 3D tomography of soil parameters, we develop a modular Ground Penetrating Radar (GPR) monitoring system with 39 DAQ modules, each containing 64 antennas. The modules will be mounted around a soil-filled lysimeter with a height of 1.5 m and a diameter of 1 m. The GPR emits a 3 ns long time domain pulse generated by one of its modules DACs. The signal is guided through a 1-to-64 multiplexer to one antenna, penetrates through the soil and is received by another antenna at the other side of the lysimeter. The received signal is amplified and multiplexed to one of eight ADCs of the corresponding DAQ module. This is done for all antenna combinations. All DAQ modules are controlled, triggered and synchronized by a central main module that also collects the measurement data from the modules and forwards them to an external storage. The topology of the DAQ system is a mixture of a star topology for the first 13 modules followed by a daisy chain topology to connect two additional DAQ modules to each of the first modules. A full tomogram will take about 8 s and contains up to 25 GB of data. Initial evaluations show a synchronisation accuracy of about 40 ps. A system with two DAQ modules was recently tested at a real lysimeter.
| Minioral | Yes |
|---|---|
| IEEE Member | No |
| Are you a student? | No |