Showing papers by "Norman S. Kopeika published in 2016"
TL;DR: In this paper, an upconversion of millimeter wave and terahertz radiation to the visual band using a very inexpensive miniature glow discharge detector (GDD) and a silicon photodetector is presented.
Abstract: We present an inexpensive technique to obtain a three-dimensional (3D) millimeter wave (MMW) and terahertz (THz) image using upconversion. In this work we describe and demonstrate a method for upconversion of MMW/THz radiation to the visual band using a very inexpensive miniature glow discharge detector (GDD) and a silicon photodetector. We present MMW/THz upconversion images based on measuring the visual light emitting from the GDD rather than its electrical current. The results show better response time and better sensitivity compared to the electronic detection performed previously. Furthermore, in this work we perform frequency modulation continuous wave (FMCW) radar detection based on this method using a GDD lamp, with a photodetector to measure GDD light emission. By using FMCW detection, the range in addition to the intensity at each pixel can be obtained, thus yielding the 3D image. The GDD acts as a heterodyne mixer not only electronically but also optically. The suggested 3D upconversion technique using the GDD is simple and inexpensive and has better performance compared to other MMW/THz imaging systems suggested in the literature. This method provides minimum detectable signal power that is about 6 orders of magnitude better than similar plasma systems due to the very large internal signal gain deriving from the much smaller electrode separation and resulting in much higher plasma electric field.
18 citations
TL;DR: In this article, the authors proposed a simple way to measure the distance to the object target with high resolution based on very inexpensive glow discharge detectors (GDDs) at terahertz (THz) band frequencies.
Abstract: A well-known method for range applications is chirped frequency modulated continuous wave (FMCW) radar. We offer a simple way to measure the distance to the object target with high resolution based on very inexpensive glow discharge detectors (GDDs) at terahertz (THz) band frequencies. Proof of concept of THz FMCW radar using a GDD is experimentally demonstrated in this paper. The advantage of FMCW in the THz band is its better range resolution compared with FMCW radar in the microwave band due to wider frequency swing. Such a system using a GDD has the following advantages: very inexpensive and simple to realize, rigid components, room temperature operation, fast response time, and high power radiation immunity. Those properties are very important in the realization of high resolution 3-D imaging in the THz band. Depth resolution on the order of 7.5 mm can be achieved by the proposed system.
13 citations
25 Oct 2016
TL;DR: In this article, a novel deterministic approach was used which is based on the remote sensing data to retrieve actual evapo-transpiration (ET) as a function of water availability can be measured remotely with infrared radiometers.
Abstract: The advancements in remote sensing in combination with sensor technology (both passive and active) enable growers to analyze an entire crop field as well as its local features. In particular, changes of actual evapo-transpiration (ET) as a function of water availability can be measured remotely with infrared radiometers. Detection of crop water stress and ET and combining it with the soil water flow model enable rational irrigation timing and application amounts. Nutrient deficiency, and in particular nitrogen deficiency, causes substantial crop losses. This deficiency needs to be identified immediately. A faster the detection and correction, a lesser the damage to the crop yield. In the present work, to retrieve ET a novel deterministic approach was used which is based on the remote sensing data. The algorithm can automatically provide timely valuable information on plant and soil water status, which can improve the management of irrigated crops. The solution is capable of bridging between Penman-Monteith ET model and Richards soil water flow model. This bridging can serve as a preliminary tool for expert irrigation system. To support decisions regarding fertilizers the greenness of plant canopies is assessed and quantified by using the spectral reflectance sensors and digital color imaging. Fertilization management can be provided on the basis of sampling and monitoring of crop nitrogen conditions using RS technique and translating measured N concentration in crop to kg/ha N application in the field.
2 citations
21 Oct 2016
TL;DR: This work presents 100 GHz up-conversion images based on measuring the visual light emitting from the GDD rather than its electrical current, which showed better response time of 480 ns and better sensitivity compared to the electronic detection that was performed in the previous work.
Abstract: In this work we describe and demonstrate a method for up-conversion of millimeter wave (MMW) radiation to the visual band using a very inexpensive miniature Glow Discharge Detector (GDD), and a silicon detector (photodetector). Here we present 100 GHz up-conversion images based on measuring the visual light emitting from the GDD rather than its electrical current. The results showed better response time of 480 ns and better sensitivity compared to the electronic detection that was performed in our previous work. In this work we performed MMW imaging based on this method using a GDD lamp, and a photodetector to measure GDD light emission.
2 citations