Publisher’s Note: This paper, originally published on 24 October 2018, was replaced with a corrected/revised version on 10 July 2019. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance.
It is commonly said that the global environment structure is formed from the atmosphere, hydrosphere, geosphere, and biosphere, which are natural environment systems. In addition to this, we add another system “livingsphere” which is an artificial system, but holds strong relations between the daily lives of humans and the natural systems. It would then be appropriate to consider the global environment structure with the idea that natural systems and the artificial one are interconnected. We propose using fluorescence as a common parameter to understand the interconnection. Since a large variety of substances exhibit their own unique auto-fluorescence spectrum more or less if they are irradiated by light, they are good targets for fluorescence lidars. Lidar observation results about substances moving freely among the systems might offer information about the interconnection of each type of environment system. In this presentation, we show several experiments done using the fluorescence lidar we have developed for observing aerosol in the atmosphere, lake/river water quality in the hydrosphere, vegetation growth status in the biosphere, and pre-observing ground surface substances in the geosphere and waste substances of daily necessities in the livingsphere. We also describe a fluorescence database which is an EEM (Excitation-Emission-Matrix) of substances found elsewhere in the systems, and discuss an adaptation of the database to the atmospheric aerosols observation done by the fluorescence lidar.
We propose the use of “Optical Farming,” which is the leading application of all types of optical technologies, in agriculture and
agriculture-related industries. This paper focuses on the optical sensing instruments named “Agriserver,” “Agrigadget” and “LIFS
Monitor” developed in our laboratory. They are considered major factors in utilizing Optical Farming. Agriserver is a sensor network
system that uses the Internet to collect information on agricultural products growing in fields. Agrigadget contains several optical
devices, such as a smartphone-based spectroscopic device and a hand framing camera. LIFS Monitor is an advanced monitoring
instrument that makes it possible to obtain physiological information of living plants. They are strongly associated with information
communication technology. Their field and data usage performance in agricultural industries are reported.
Laser-induced fluorescence (LIF) is emitted from leaf pigments irradiated with laser. LIF contains lots of information on living plants, so LIF spectroscopy, also known as the LIF technique, is a powerful tool for plant investigation. This paper mainly describes 1) the information that is obtained by plant LIF experiments with a focus on plant physiological information, and 2) practical field applications of the LIF technique, especially to agriculture and forestry, together with a detailed description of equipment systems. Through several experimental results, the usefulness of the LIF technique is discussed as a field monitoring technique for plant investigations. Finally, the concepts of a "general hospital for plant diagnosis" and "optical farming for the agricultural industry" based on LIF information are proposed.
Sum frequency generation of sodium D2 resonance radiation (589 nm) based on injection seeded Nd:YAG lasers was applied to a sodium lidar transmitter for temperature measurements of the mesopause region (80-105km). The output energy was 40 mJ / pulse at a repetition rate of 10 Hz and a temporal width of 28 nsec. The laser wavelength at 589 nm (~0.04 pm FWHM) was finely tuned with an accuracy of 0.1pm by seeders. The lidar installed at Syowa station (69°S, 39°E), Antarctica, measured temperature profiles between March and September during 2000 and 2001. Monthly averaged temperature profiles in the mesopause region in wintertime (June, July and August) are nearly 20 K lower than those in the northern hemisphere sites. The measured winter mesopause altitudes (~99 km) are in good agreement with those measured in the northern winter hemisphere. The mesopause temperatures (~175 K) in winter months however are about 20 K lower than those observed from a northern hemisphere conjugate site, Andoya (69°N). The lower winter mesopause temperatures measured at Syowa station, which are consistent with southern hemisphere mesopause temperatures measured by a shipborne lidar, suggest the existence of a hemispheric difference. Possible causes for this difference are discussed.
We have developed the bistatic imaging lidar for measuring the lower atmosphere at the daytime as well as at nighttime. The lidar has composed of a transmitting system of a Nd: YAG laser (532nm, 10Hz, and 5OmJ) and a receiving system of a cooled high-sensitive CCD camera with an image intensifier as a high-speed shutter. Vertical profiles could be obtained every one minute and indicated in a real time monitor with color contoured time-height indication. We have been making regularly the 24 hours observations of the atmospheric boundary layer once a week at the inland district capital, Nagano City, closed in by the high mountains since August 1999. Some interested results have been obtained from the temporal and seasonal variations of the boundary layer. We describe the oscillatory rising motion of the top height of the boundary layer in the morning, the diffusion of aerosols due to car fumes during the rush hours both in the morning and in the evening and the downward motion of the cloud base height just before rain or snow. Moreover, it is reported about the difference of boundary layer activities between in summer and in winter under an inland climate.
KEYWORDS: Clouds, Multiple scattering, Laser scattering, Scattering, LIDAR, Monte Carlo methods, Photons, Mass attenuation coefficient, CCD cameras, Imaging systems
Laser multiple scattering phenomena occurring inside a cloud were experimentally confirmed by showing the spread of the scattered laser light as a two-dimensional spatial distribution image. By changing the gate delay time of a CCD camera, range-resolved scattering images were obtained with a gate time width of 100 ns, which corresponds to a resolution of 15 m cloud depth. The size of the scattering area enlarged just after the laser pulse hit the cloud, and gradually decreased as the beam went deeper inside the cloud where extinction overcame the multiple scattering. An extinction coefficient of 3.62x102 [ m-1] was calculated from the laser beam transmission. The particle size distribution of the cloud was derived to fit the obtained extinction coefficient. A Monte Carlo simulation using the new distribution function reproduced the experimental scattering image very well. This new experimental and simulation method to show the multiple scattering as a spread image will provide informative knowledge for cloud lidar observations.
Observation of mesospheric temperature profiles with a new sodium lidar has started at Syowa Station (69° 00'S, 390° 3 5'E) since February, 2000. The transmitter is composed from injection seeded Nd:YAG lasers of 1064 nm and 1 3 1 9 nm, producing sodium resonance line at 589 nm by sum frequency generation. The advantage of this instrument is the transmitter is simple thus transportable, and a reliable solid state system requiring less maintenance compared with ordinary type of dye laser transmitters. The 589 nm laser bandwidth is well narrowed less than 100 MHz, pulse width is 40 nsec, and the energy is 40 mJ/pulse. The 589 nm wavelength is controlled by a personal computer with monitoring a seed laser wavelength using a wavemeter with an accuracy of 0. 1 pm. Temperature structures were measured by two frequency technique and by sodium D2 Doppler profile filling. Both results were in good agreement and consistent with model temperature structure.
We applied the laser-induced fluorescence (LIF) method to the monitoring of plant disease caused by environmental changes. An LIF spectrum measurement system and an LIF lifetime measurement system were developed for this purpose. The former one was constructed with a 6 ns, 355-nm Nd: YAG laser and a multiwavelength spectroscopic detection system. The later one was constructed with a 300 fs, 660-nm laser and a streak scope with a time resolution of 25 ps. Morning glory and Zelkova were prepared to investigate disease process monitoring by the LIF measurement system. The LIF spectra of the stressed leaves showed that the spectral intensities at 460 nm and 530 nm rapidly increased for 3 hours and then decreased for 20 hours, while the spectra at 685 nm and 740 nm decreasing constantly. In the LIF lifetime measurement, the chlorophyll fluorescence lifetime of Zelkova leaves was measured at 685 nm and 740 nm. It was found that the lifetime was composed of a fast component of about 100 ps and a slow one of about 600 ps and after UV-B irradiation the lifetime varied sinusoidally among the lifetime of normal leaves. Through these experiments the performance of the systems was checked and their potential for plant disease process monitoring was confirmed.
We have been developing a bistatic imaging lidar using a high sensitive CCD camera with an image intensifier as a high speed shutter for measuring spatial distributions of aerosols, fogs and clouds in the lower atmosphere at daytime as well as at nighttime. The bistatic imaging lidar was applied to two field observation campaigns. One was made cooperatively with a wind profiler and a radiosonde at Moriya (36 km north of Tokyo) for five days from May 26 to 30, 1997 and another cooperatively with a monostatic lidar at Hakuba alpine ski area of Nagano for 10 days from February 7 to 16, 1998 during the period of the 18th Winter Olympic Games in Japan. We report the results obtained at both campaigns and discuss the ability of this system in measuring the meteorological features of the local lower atmosphere under different conditions.
We are planning to measure the Antarctic mesopause region by a sodium temperature lidar at Syowa station (69 degrees 00' S, 39 degrees 35' E) for three years, 1999 - 2001 as a part of the 5th Campaign of Japanese Antarctic Research Expedition (JARE 40 - 42). The objective of this campaign is to clarify the mechanism of energetic interaction between the lower thermosphere and the upper mesosphere through the mesopause region over Antarctica. Lidar measurements will be made cooperatively with a MF radar and a Fabry-Perot Doppler imager. The pulse laser tuned to the sodium D2 resonance line (589 nm) can be obtained by a sum frequency of two injection seeded Nd:YAG lasers (1064 nm and 1319 nm) with a narrow spectral width below 0.2 pm. The temperature measurement can be made by detecting the Doppler broadening of sodium D2 fluorescence spectrum by tuning laser wavelength alternately at two points of its spectrum. Scattered photons are collected by a Dall-Kirkham Cassegrain telescope of 0.5 m in diameter and detected in photoncounting mode with a gated photomultiplier tube (PMT). The photons are integrated with a range-gated multichannel scaler and processed with a personal computer. Daytime measurements will be made by using an extremely narrow band Faraday filter.
We have organized a network campaign for the observation of Asian dust in the spring of 1997 and 1998 in Japan. Through the communication with electric mail, we have successfully observed Kosa events by lidar, sunphotometer, and particle counter, etc. These data must be useful to analyze the transport mechanism of Asian dust and validate the satellite observations.
This paper reports the optical characteristics of the Retroreflector in Space (RIS) on the advanced earth observing satellite (ADEOS) in orbit. The RIS is a 0.5 m diameter single-element hollow cube-corner retroreflector with a unique design which uses a curved mirror to correct the velocity aberration caused by the satellite movement. We used a Nd:YAG laser to test the efficiency of the reflection at 532 nm. The ADEOS was actively tracked with a 1.5 m diameter tracking telescope using the image of the RIS lit by the Nd:YAG laser. We measured the intensity of return light with an image-intensified CCD camera on the guiding telescope with a diameter of 20 cm. The intensity of the return was quantified by comparing it with images of stars. We compared the result with the theoretical reflectance of the RIS, and confirmed that the reflectance of the RIS agreed with the designed value. The return from the RIS was comparable to a stellar magnitude of 2 to 3, depending on the elevation angle when lit by a 0.3 W laser with a beam divergence of 0.5 mrad.
We conducted an earth-satellite laser long-path absorption experiment using the Retroreflector in Space on the advanced earth observing satellite, which was launched on August 17, 1996 by the National Space Development Agency of Japan. Two single-longitudinal-mode transverse, electric, atmospheric (TEA) CO2 lasers were used in the spectroscopic measurement of atmospheric trace species. One TEA laser was used to measure the absorption of the ozone, and the other to record a reference signal. We measured the absorption spectrum of the atmosphere using the Doppler shift of reflected beam caused by the satellite's movement. The ozone spectrum was successfully measured using the 10R(24) line of 13CO2 and the 9P(24) line of 12CO2. We studied the measurement error and reduced it by adding a spatial filter to the transmitter optics.
Two different types of laser-induced fluorescence (LIF) imaging systems, a microfluorescence imaging system and a fluorescence imaging lidar system, have been developed for visualization of the fluorescence of plants to investigate and monitor their physiological status and so on. By using the microfluorescence imaging system, the distribution structures of the fluorescence inside tree leaves was obtained and the relationships among the cell/tissue locations, fluorescences and environmental stresses were investigated. Also, through outdoor experiments with the LIF imaging lidar, parameters related to the chlorophyll content of poplar leaves, which were about 60 m away from the system, were remotely estimated and visualized. It was shown that there was a close relationship between the results with both imaging systems and the LIF spectra emitted through leaf surfaces. The combination of the two systems will surely be a powerful tool for vegetation/plant monitoring.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.