Wheat Radar (Compact)
The purpose of this instrument is to efficiently and non-destructively measure architecture parameters of wheat canopies for breeding applications. Specifically, this radar system collects coherent radar measurements of wheat breeding plots in nadir mode from a mobile platform. Plant structural parameters are derived from the radar measurements. These phenotyping measurements could be used to relate desirable structural traits of plants to genome-wide markers. These relationships would be useful for developing the prediction models for Genomic Selection of cultivars with high performing architectural traits.
This instrument collects coherent radar measurements of wheat canopies over the 2-18 GHz frequency rage with a PRF of 500 Hz. This system uses the frequency-modulated-continuous-wave (FMCW) radar topology. This sensor consists of a digital section, a microwave front-end section and a set of antennas. The digital section of the radar includes the direct digital synthesizer (DDS) sub-system and the digital-acquisition-system (DAQ). The microwave front-end section includes the chirp generator, the transmitter, the local-oscillator (LO) conditioning system and the receiver.
A wheeled phenotyping cart was developed to support the radar antennas and electronics, while collecting radar measurements of wheat canopies in nadir mode. The cart was designed to move at a fast pace of about 0.5 m/s Both the transmit and receive antennas are attached to the mobile platform at 1.8 m above the ground. The antennas are oriented facing the nadir direction and they are separated by 0.6 m from each other. These antennas are pyramidal horn antennas with model number QWH–SL–2–18–S–SG–R. The frequency range of the antennas is 2–18 GHz, the average antenna gain is 10 dBi and the average beamwidth is 56.6 degrees.
Sample Radar Echogram of a wheat breeding plot measured during the flowering growth stage. This measurement was collected on 5/22/2018. The wheat crops measured belonged to KSU wheat breeding program, and they were located at Tom Pauly Seed Fields