Fluorescence Mapping of Agricultural Fields Utilizing Drone-Based LIDAR

Abstract

A compact and low-weight LIDAR instrument has been developed for laser-induced fluorescence spectroscopy sensing of maize fields. Fluorescence LIDAR had to be installed on a small industrial drone so that its mass was <2 kg and power consumption was <5 W. The LIDAR instrument utilized a continuous wave diode laser (405 nm, 150 mW) for inducing fluorescence and a small spectrometer for backscattered photons acquisition. For field testing, the LIDAR instrument was installed on a quadcopter for remote sensing of plants in a maize field in three periods of the plant’s life. The obtained fluorescence signal maps have demonstrated that the average chlorophyll content is rather non-uniform over the field and tends to increase through the plant vegetation cycle. Field tests proved the feasibility and perspectives of autonomous LIDAR sensing of agricultural fields from drones for the detection and location of plants under stress.

Cold Acclimation and Deacclimation of Winter Oilseed Rape, with Special Attention Being Paid to the Role of Brassinosteroids

“…In our research, the results were obtained in control conditions; thus, it is advisable that the pattern of the changes of specific parameters be confirmed in open-field conditions. However, the positive information is that non-invasive methods for the early detection of deacclimation could also be useful on a large scale by using drones or satellites to detect any changes in reflectance [ 58 , 67 ] or changes in chlorophyll a fluorescence [ 68 ].…”

Optical Methods for the Detection of Plant Pathogens and Diseases (Review)

“…In the controlled conditions of laboratories [34] and post-harvest sorting lines [10], any conditions can be created, although there are also limiting factors: in laboratories, it is often the size of the premises; in line conditions, it is dust and soil residues. To scan and diagnose large areas, instruments for remote sensing from ground platforms, aircraft and satellites are used [35]. The majority of optical methods are non-destructive and non-invasive, but, for certain purposes, there is a need for and benefit of invasive monitoring methods.…”

“…The method of laserinduced fluorescence stands somewhat apart. With the income generated by the usage of laser light sources with high intensity, it became possible to study whole plants even with remote sensing instruments, to discover the development of stress caused by herbicides [35] and pathogens [111,112]. Natural lighting is often a hindrance to fluorescence methods.…”

“…Often, this problem is solved by pulsed laser operation. Another means to remove such interference is to correct the obtained spectrum for the background spectrum with the laser turned off [35]. Solar radiation is not always a hindrance to measurement; for example, there is an interesting method to detect sunlight-induced chlorophyll fluorescence-a method based on the isolation of Fraunhofer lines, 687 and 760 nm, overlapping with the red and far-red bands of the chlorophyll spectrum used for remote sensing [113].…”

A Prototype Method for the Detection and Recognition of Pigments in the Environment Based on Optical Property Simulation

“…However, to perform measurements on the stud pigments (Figure 1B), they have to be isolated from proteins and placed in a cuvette w buffer (Figure 1A,C). In vivo measurements can be taken using the laser remote sens technique [6][7][8][9][10], but the interpretation of the obtained signal is difficult [11] since pigments are directly in the living organism and their optical properties are differ fr those of pigments in solvents. The main feature of the spectrum of any organic pigment is that its electronic sorption bands are quite broad (Figure 1D) and its line profile is usually irregul shaped [12].…”