Wheat crop biophysical parameters retrieval using hybrid-polarized RISAT-1 SAR data

Chauhan, Sugandh; Srivastava, H. S.; Patel, Parul

doi:10.1016/j.rse.2018.06.014

Cited by 37 publications

(21 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2) Experiments and Results: We use the ALOS-2 data that was used in Section IV. We plot the scattering states on the scattering sphere for the areas of Field, Town, Forest and Lake We chose three 100 × 100-pixel sample areas for each land cover class by considering the heterogeneity [34], [35]. Fig.…”

Section: Compensation Of Polarimetric Changes In the Ppo-bd Optimimentioning

confidence: 99%

Consideration on Singular-Point Generating Mechanisms by Analyzing the Effect of Phase-and-Polarization Optimization in PolInSAR

Otsuka

Shimada

Natsuaki

et al. 2020

IEEE J. Sel. Top. Appl. Earth Observations Remote Sensing

View full text Add to dashboard Cite

We elucidate the generation mechanisms of singular points (SPs) by investigating the relationship between the phase distortion and the polarization-state changes in polarimetric interferometric synthetic aperture radar (PolInSAR). We find that there is a high correlation between the parameters in the Pauli coherency matrix and those in the scattering mechanism vector optimized by the maximization of interferometric coherence. It means that there is a correlation between the parameters of polarization and those of the phase compensation. In other words, the main changes in phase and those in polarization are caused by an identical phenomenon, that is, scattering itself. Therefore, we can use the parameters of polarization to reduce SPs. We also find that other origins that cause the changes in phase are the interference of waves from multiple scattering sources and thermal noise. Lastly, we investigate how the optimization compensates polarization changes by introducing the scattering sphere representation. We find that the optimization reduces randomness in the polarimetric features, and enhances the features specific to deterministic scattering such as surface and double-bounce scattering. It means that probabilistic/random scattering is the main origin of SP generation.

show abstract

Section: Compensation Of Polarimetric Changes In the Ppo-bd Optimimentioning

confidence: 99%

Consideration on Singular-Point Generating Mechanisms by Analyzing the Effect of Phase-and-Polarization Optimization in PolInSAR

Otsuka

Shimada

Natsuaki

et al. 2020

IEEE J. Sel. Top. Appl. Earth Observations Remote Sensing

View full text Add to dashboard Cite

show abstract

“…The way vegetation responds to changing ecological and climatological conditions is reflected by an immediate or slow change in its biophysical and biochemical properties (Hong et al, 2007). The retrieval of such plant properties by RS methods has been well established and documented (Inoue et al, 2016;Chakraborty et al, 2005;Verrelst et al, 2015;Neinavaz et al, 2016;Chauhan et al, 2018;Holzman et al, 2018), and can be extended further to extract lodging-related information. A RS-based approach to study crop lodging requires (i) understanding of specific plant traits, which make a plant susceptible to lodging or can help to assess the occurrence of lodging; and (ii) identification of appropriate modelling approaches.…”

Section: Lodging and Its Impact On Agricultural Productionmentioning

confidence: 99%

Remote sensing-based crop lodging assessment: Current status and perspectives

Chauhan

Darvishzadeh

Boschetti

et al. 2019

ISPRS Journal of Photogrammetry and Remote Sensing

Self Cite

View full text Add to dashboard Cite

Rapid and quantitative assessment of crop lodging is important for understanding the causes of the phenomena, improving crop management, making better production and supporting loss estimates in general. Accurate information on the location and timing of crop lodging is valuable for farmers, agronomists, insurance loss adjusters, and policymakers. Lodging studies can be performed to assess the impact of lodging events or to model the risk of occurrence, both of which rely on information that can be acquired by field observations, from meteorological data and from remote sensing (RS). While studies applying RS data to assess crop lodging dates back three decades, there has been no comprehensive review of the status, potential, current approaches, and challenges in this domain. In this position paper, we review the trends in field/lab-based and RS-based studies for crop lodging assessment and discuss the strengths and weaknesses of current approaches. Theoretical background on crop lodging is presented, and the scope of RS in assessing plant characteristics associated with lodging is reviewed and discussed. The review focuses on RS-based studies, grouping them according to the platform deployed (i.e., ground-based, airborne and spaceborne), with an emphasis on analyzing the pros and cons of the technology. Finally, the challenges, research gaps, perspectives for future research, and an outlook on new sensors and platforms are presented to provide state-of-the-art and future scenarios of RS in lodging assessment. Our review reveals that the use of RS techniques in crop lodging assessment is still in an experimental stage. However, there is increasing interest within the RS scientific community (based on the increased rate of publications over time) to investigate its use for crop lodging detection and risk mapping. The existing satellitebased lodging assessment studies are very few, and the operational application of the current approaches over large spatial extents seems to be the biggest challenge. We identify opportunities for future studies that can develop quantitative models for estimating lodging severity and mapping lodging risk using RS data. 1.2. The role of remote sensing The past few decades have witnessed considerable growth in the use of sensors on-board Earth-Observation (EO) systems for agricultural monitoring applications. Today, crop biophysical properties such as leaf

show abstract

“…SAR backscattering coefficients are primarily a function of crop structure (such as size, orientation and density of scatterers in the plant) and the dielectric properties of crop canopy as well as underlying soil moisture (particularly at initial phenological stages when the vegetation is scarce and more soil surface is exposed) (Chauhan et al, 2018;Forkuor et al, 2014). The trends vary from crop to crop and change with crop condition.…”

Section: General Characteristics Of the Backscattering Coefficients Amentioning

confidence: 99%

“…6.8b). The microwave signal is highly sensitive to the structure and geometry of the canopy and is a function of size, orientation and density of the scatterers/target (Chauhan et al, 2018). As a microwave signal hits the crop canopy, there are three forms of scattering mechanisms that can occur: surface/single-bounce, double-bounce, and volume scattering.…”

Section: Relationship Between Satellite Metrics and Sf Amentioning

confidence: 99%

“…In this context, synthetic aperture radar (SAR) sensors offer a clear advantage since microwaves are less affected by the atmosphere and can image the Earth's surface successfully irrespective of weather conditions. Also, the unique sensitivity of microwave scattering to crop structure has led to many studies utilizing the SAR data for crop monitoring (Chauhan et al, 2019c(Chauhan et al, , 2018Lopez-Sanchez et al, 2011;Nelson et al, 2014a;Yuzugullu et al, 2017). However, a recent review by revealed that only eight peer-reviewed articles published between 1951-2018 have focused on the use of SAR data for lodging assessment, four of which utilized data acquired from spaceborne platforms Han et al, 2017;Yang et al, 2015;Zhao et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation