Crop Identification and Health Assessment Through Nanoscale Spectral Remote Sensing Inputs

Research Article

Ann Agric Crop Sci. 2024; 9(5): 1168.

Crop Identification and Health Assessment Through Nanoscale Spectral Remote Sensing Inputs

Muhammad Usman Saeed¹; Imdad Ullah¹*; Saeed Ahmad²

¹School of Economics, Bahauddin Zakariaya University, Multan, Pakistan

²Language Centre, University of Eastern Finland, Finland

*Corresponding author: Imdad Ullah, School of Economics, Bahauddin Zakariaya University, Multan, Pakistan. Email: muhammadusmansaeed66@gmail.com

Received: October 15, 2024; Accepted: November 04, 2024 Published: November 11, 2024

Abstract

Food, textiles, fuel, and raw materials are produced through agriculture, all essential for human survival. At the same time as the human population is reaching previously unheard-of heights and continuing to grow, this function must be fulfilled in the current environment of environmental sustainability, climate change, and the continued viability of agricultural activities to provide for both subsistence and livelihoods. Remote sensing has the potential to support the adaptive evolution of agricultural methods to meet this significant challenge by consistently providing data on crop status throughout the growing season at various scales and for multiple actors. Significant improvements in capabilities, particularly the creation of spectral-temporal profile models, can be used for crop identification. As inputs to crop growth and yield models, the same model form can be used to estimate crop development stage, leaf area index, and canopy light interception. We have taken the data from six important crops and compared the spectral pattern and leaf properties to understand the rule and potential of nanoscale remote sensing to identify crop health at the growing stage. Understanding Crop breeding, monitoring agricultural land usage, predicting crop yields, and ecosystem services related to soil and water resources or biodiversity loss is crucial.

Keywords: Crops vegetation; Precision farming; Ecosystem services; Chlorophyll

Introduction

History has documented significant and irregular variations in crop output worldwide. Crop production has varied dramatically over the previous three decades, even as new, higher-yielding crop types and improved production techniques have been deployed. Effective crop production, processing, distribution, and marketing decisions depend on timely and precise crop production predictions and estimates [22,23]. Understanding agricultural conditions worldwide is particularly planting bed to a need for accurate, current information on global food supplies; decisions on plan-recurrent selling, storing, transporting, and buying must be made with partial information. However, only a few countries have adequate systems for obtaining and reporting crop production statistics; accesses vary significantly from country to country.

During the past few years, we have discovered that remote sensing from aeronautical platforms may deliver precise, fast data on crop output. Large-area crop surveys are made possible by the synoptic view of agricultural landscapes afforded by multispectral sensors on satellite platforms in conjunction with computer-aided analytical techniques [1]. The Large Area Crop Inventory Experiment (LACIE) amply proved the viability of using satellite-acquired multispectral data to identify and estimate the area of one crucial crop, wheat. Later, the USDA, NASA, and NOAA's AgRlSTARS program later expanded the LACIE crop identification-area estimation methodology to accommodate other crops and locations [10,11].

All energy that travels in a harmonic wave pattern at the speed of light is known as Electromagnetic (EM) energy. A harmonic wave pattern comprises waves that happen at regular intervals. The EMR has both a wave model and a particle model. The wave model explains the propagation (movement) of EM energy. The interaction between this energy and the substance, however, is what allows for its detection. In this interaction, photons, which are numerous individual bodies/particles with such particle-like qualities as energy and momentum, behave like EM energy contain reviews on the nature of EM radiation and physical principles [9,11]. The EMS is a continuum of energy propagating through vacuums like space at the speed of light (3 × 108 ms-1), with wavelengths ranging from meters to nanometers. The EMS covers a wide range of wavelengths, from 10-10 μm (cosmic rays) to 1010 μm (radio waves) [21]. The EMS's ultraviolet, visible, infrared, and microwave sections have all been broadly classified. However, these distinctions were made at random. The boundary between one nominal spectral region and the next must be clarified. The region of the EMS where optical techniques of refraction and reflection can be utilized to focus and divert radiation is known as the visual wavelengths, which range from 0.30 to 15 μm. EM energy can be refracted and reflected by solid materials at these wavelengths. The reflective section of the spectrum is often defined as the range between 0.38 and 3.0 μm [12,33]. Most energy detected at these wavelengths is solar radiation reflected off Earthly objects.

The term "ultraviolet," which refers to an area of short-wavelength radiation between the X-ray zone and the visible range (0.40 to 0.70 μm) of the EMS, literally means "beyond violet." The near ultraviolet (0.32 to 0.40 μm), the far ultraviolet (0.32 to 0.28 μm), and the extreme ultraviolet (below 0.28 μm) are three standard divisions of the ultraviolet region. These divisions are often called UV-A, UA-B, and UA-C, respectively [24].

The Near-Infrared (NIR) ranges in wavelength from 0.72 to 1.30 μm, the middle infrared/shortwave infrared ranges from 1.30 to 3 μm, and the far infrared ranges from 7.0 to 15.0 μm. The infrared region spans from 0.72 to 15 μm and has been split into these three main divisions. The behavior of radiation in the NIR range is similar to that in the visible spectrum. As a result, films, filters, and cameras made for visible light can also be used for remote sensing in the NIR [21,38]. The far-infrared region (7.0 to 15 μm) includes wavelengths that go well beyond the visible spectrum and extend into areas next to the microwave spectrum. The Earth mainly emits far-infrared radiation. No particular name typically refers to the range of wavelengths from 3.0 to 7.0 μm [35].

The microwave spectrum spans a distance of 1mm to 1m. The longest wavelengths frequently employed in remote sensing are microwaves. The thermal energy of the far-infrared region shares many characteristics with the shortest wavelengths in this range. It is further separated into various frequency bands frequently employed in remote sensing (1 GHz = 109Hz). In contrast to the optical portion of EMS, where spectral bands are defined by wavelength, the microwave region of EMS often uses frequencies to do so [3-5]. About 4% of all solar radiation entering the planet is reflected into space by the Earth's land surface. The atmosphere reflects the remaining energy or absorbs it and emits it as infrared radiation. The varied surface features of the Earth absorb and reflect radiation at various wavelengths in varying amounts. The spectral response pattern of an object refers to the amount of energy it emits or reflects throughout a broad range of wavelengths [12,13]. These responses have frequently been referred to as spectral signatures because spectral responses obtained by distant sensors over a variety of features often allow an assessment of the type and condition of the features. Even though many Earth surface features exhibit distinctive spectrum reflectance and emittance characteristics, these traits produce spectral "response patterns" rather than spectral "signatures." The term signature tends to imply an absolute and singular pattern, which is why this is the case. The spectral patterns seen in the natural world do not work like this [9].

The spectral reflectance pattern of the main elements of the terrain, including the soils, plants, and shallow and deep water. Vegetation is highly noticeable in its ability to absorb incident light in the blue (400 to 500 nm), red (600 to 700 nm), and shortwave-infrared regions (at 1400, 1900, and 2600 nm) wavelength ranges (Bian et al. 2016). While chlorophyll, which gives plants their green color, is responsible for absorptions in the blue and red spectrum, water absorbs incident light in the shortwave-infrared range [8].

Contrary to vegetation, water reflects more in the blue region (400 to 500 nm) and absorbs most in the NIR area (700 to 1300 nm), according to this comparison of these two spectral response patterns. Notably, the NIR area is where vegetation reflects the most. Using air/space carried multispectral images, this contrasting feature enables vegetation recognition from water bodies [28]. On the other hand, soils, except for two absorption bands centered on 1400 and 1900 nm, have a rising trend in their spectral reflectance pattern with increasing wavelengths.

The word "hyper" in "hyperspectral" refers to the numerous measured wavelength bands and signifies "over" as in "too many." Because hyperspectral images are spectrally over determined, so they provide sufficient spectral information for identifying and distinguishing objects [4]. The word "hyper" in "hyperspectral" refers to the numerous measured wavelength bands and signifies "over" as in "too many." Because hyperspectral images are spectrally over determined, so they provide sufficient spectral information for identifying and distinguishing objects [1].

Every object, alive or inanimate, has a unique spectral signature encoded in the spectrum of the light it reflects or emits. The constituent substances' electronic and vibrational energy states govern the object's distinct spectrum properties [29]. Through various spectrum analysis techniques, these spectral features enable that object or importance to be recognized.

The strength of the measurements of the spectral response patterns in several contiguous, narrow spectral bands has been acknowledged. Landsat -TM's spectral bands are denoted by the numerals 1 through 7, and their bandwidths are shown in distinct blue lines. At seven locations between 350 and 2,500 nm, the spectral response of green vegetation has been combined and given a blue color [32,35]. Green is used consistently throughout to represent the hyperspectral response pattern of green vegetation. Green foliage has a constant spectral response pattern, except between 1,800 and 2,000 nm. Due to discontinuous and broad spectral bands, the thematic Mapper could not record the water absorption band at 1,400 nm and two absorption patterns in the near-infrared plateau at 1,000 nm and 1,200 nm. Similarly, it is possible to create spectra for different terrain features, such as soil, water, and plants.

The hyperspectral data are challenging to visualize simultaneously due to their several spectral bands. Making an image cube is one method of comprehending the patterns in the data because each ground scene can be composed of hundreds of images (bands). The spatial dimensions that display the terrain's ground surface are the x and y axes. All the other bands make up the z-axis as if they were piled like a ream of paper and turned on their side. The top image is a three-band composite created from three bands (often R, G, and B) for presentational purposes. The colors streaming away from the edges are the edge pixel values along the z-axis, which are rainbowcolored from blue to red [12,37]. This way, one can observe how the spectra vary and that a tremendous amount of information is stored in ranges by following an edge pixel in this cube along the z-axis.

A platform, instrumentation (sensor), data reception, processing, and analysis comprise a remote sensing system that measures, observes, and forecasts the Earth's system's physical, chemical, and biological elements. Our objective of this study is to identify the rule of the nanoscale spectral remote sensing inputs to monitor the health of the crop and compare the spectral signatures pattern and the leaf characteristics of the six different vegetables and cereal crops.

Material and Methods

Data

The optical characteristics of crop leaves can be measured through experimental processes, and deterministic methods based on various models of light interactions with crop leaves can also be created. The underlying physics and the leaf 's complexity set these models apart [36]. The simplest ones treat the blade as a single scattering and absorbing layer. The structure, size, location, and molecular makeup of each cell have been defined in detail in the more complex ones. Whatever the method, these models have increased our comprehension of how light interacts with plant leaves. They can be divided into many classes and ordered according to increasing complexity. We collect the data for five crops from https://ecosis.org/ package/leaf-optical-properties-experiment-database--lopex93-

Satellite-based remote sensing systems play a vital role in agricultural applications by providing a wide spatial coverage and a systematic acquisition of data. These systems consist of Earthobserving satellites equipped with various sensors designed to capture different spectral bands of the electromagnetic spectrum (Figure 1).