Capability of Navic, an Indian GNSS Constellation, for Retrieval of Surface Soil Moisture

Chamoli, Vivek; Prakash, Rishi; Vidyarthi, Anurag; Ray, and Ananya

doi:10.2528/pierc20090904

Cited by 15 publications

(9 citation statements)

References 14 publications

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“…to determine the relationship between NavIC signal intensity and angle of elevation. These mathematical models can be used in a variety of applications, including soil moisture estimation [8][9][10][11][12][13][14]. The measurement of soil moisture content is important in the fields of agriculture, climate monitoring, climate change, soil erosion, etc.…”

Section: In This Study Mathematical Model For Both Direct and Multipa...mentioning

confidence: 99%

Mathematical Model Development for Navigation with Indian Constellation (NavIC) L-Band Geo Synchronous Satellite's Direct Signal and Multipath Signals

Chamoli

Prakash²,

Vidyarthi³

2022

Wireless Pers Commun

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NavIC L-band satellite signal that travels from the satellite to the receiver undergoes mainly shadowing and multipath effects. In this research paper, NavIC satellites were observing and analyzing signal efficiency for both the direct signal and multipath signal over the Dehradun area. Two open space data series (Direct signal and Multipath signal) for Dehradun were obtained in this analysis by the satellite receiver. The methodology includes evaluation, testing, and analysis of data in both cases. Based on collected data, a general mathematical model has been developed, describing the signal intensity in the open space context. The both NavIC Mathematical model was validated with the experimental data. The average R 2 and RMSE values developed for the direct signal mathematical model were 0.89 and 1.08% respectively which show a good prediction of NavIC C/N0 value with the developed model. For the multipath mathematical model, four cases have been evaluated. Comparing the graphical view of all four cases for C/No multipath signal concerning raw NavIC C/No multipath signal has been done to select the best mathematical model.

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Section: In This Study Mathematical Model For Both Direct and Multipa...mentioning

confidence: 99%

Mathematical Model Development for Navigation with Indian Constellation (NavIC) L-Band Geo Synchronous Satellite's Direct Signal and Multipath Signals

Chamoli

Prakash²,

Vidyarthi³

2022

Wireless Pers Commun

Self Cite

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“…GNSS-IR technique provides low spatial resolution because multipath signals are received from the Fresnel zone using a low-height ground-based antenna. The height of antenna, as stated in various studies, is close to 2 m from the soil surface [2,3,6,11,13]. GNSS-IR has the advantage of cancelling out all the atmospheric disturbances as it works on path delay between the direct and reflected signal.…”

Section: Introductionmentioning

confidence: 99%

“…GNSS-IR has the advantage of cancelling out all the atmospheric disturbances as it works on path delay between the direct and reflected signal. The amplitude, phase, and frequency of generated sinusoidal interference at lower elevation angles are the observables that are analyzed in the study of soil moisture and termed as multipath amplitude, multipath phase, and multipath frequency, respectively [1,3,6,13,14]. Signals originated from GPS, GLONASS, and BDS have been mostly analyzed in the study of soil moisture over bare and vegetated soil [3,11,15].…”

Section: Introductionmentioning

confidence: 99%

Comparative Analysis of NavIC Multipath Observables for Soil Moisture over Different Field Conditions

Shekhar¹,

Prakash²,

Pandey³

et al. 2023

PIER M

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Studies of soil moisture with Global Navigation Satellite System (GNSS) have gained the attention of several researchers. Multipath amplitude, multipath phase, and multipath frequency are multipath observables that are utilized in the study of soil moisture. However, an inter-comparison of the performance of these parameters for soil moisture under different roughness and vegetation conditions is very much required to have a better insight so that more robust inversion algorithm for soil moisture retrieval with multipath observables can be designed. Therefore, this paper analyses the performance of these multipath observables for soil moisture over bare smooth soil, rough surface, and vegetated soil. Two different fields have been investigated to include the location variability. Navigation with Indian constellation (NavIC) multipath signal has been used in this study. Statistical parameters such as correlation coefficient (R), Root Mean Square Error (RMSE), and sensitivity have been determined to study the performance of multipath observable for soil moisture under different surface roughness and vegetation conditions.

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“…The most of GNSS-based soil moisture estimation research has focused on bare soil. Further, these studies have been mostly done with GPS constellation [1][2][3][4][5][6][7][8][9][10][11][12][13]. To investigate the sensitivity of the GNSS multipath signal to soil moisture, researchers looked at the multipath amplitude, phase, and frequency.…”

Section: Introductionmentioning

confidence: 99%

Navic Multipath Signal Analysis for Soil Moisture Sensitivity in the Perspective of a Winter Wheat Crop

Chamoli¹,

Prakash²,

Vidyarthi³

2022

PIER C

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The retrieval of soil moisture in the presence of vegetation has received relatively less attention than bare land when observations are made with Global Navigation Satellite System (GNSS). In plane bare land, the reflected GNSS signal is affected by the land characteristics which is dielectric constant of soil. However, in vegetated land, the reflected signal is affected by dielectric constant of soil as well as the characteristics of vegetation which makes the retrieval of soil moisture a cumbersome task in the presence of vegetation. Monitoring soil moisture in vegetated land is important for soil health and its suitability for agriculture purposes. Therefore, the analysis of soil moisture in the presence of vegetation has been studied in this manuscript by utilising the Navigation with Indian Constellation (NavIC) which is a very new entry in GNSS domain by Indian Space Research Organization (ISRO). NavIC receiver setup was installed in a wheat agriculture land situated in Dehradun, India. The wheat crop was sown in the month of November, and it was harvested in the month of April. In situ measurement of soil moisture, crop height, humidity, soil temperature, and air temperature were made. Fixed frequency method and Lomb-Scargle Periodogram (LSP) method have been analysed to determine the sensitivity of soil moisture in the presence of vegetation. 15 • to 30 • elevation angle was utilised in the study. The sensitivity analysis was carried out by categorizing the crop based on crop height. Three crop categories have been considered which are 0 to 20 cm, 20 to 80 cm, and greater than 80 cm. The correlation coefficient in the first stage of crop growth using the fixed frequency method was 0.76, which decreased to 0.42 in second stage of crop growth and finally to 0.35 in the final stage of crop growth. The correlation coefficient using LSP method was −0.68, −0.65, and −0.50 for the first, second, and third stages of crop growth, respectively. It was observed that for lower crop height (< 20 cm), fixed frequency method is more useful than LSP method. However, for higher crop height (> 20 cm), LSP method is better suited.

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Capability of Navic, an Indian GNSS Constellation, for Retrieval of Surface Soil Moisture

Cited by 15 publications

References 14 publications

Mathematical Model Development for Navigation with Indian Constellation (NavIC) L-Band Geo Synchronous Satellite's Direct Signal and Multipath Signals

Mathematical Model Development for Navigation with Indian Constellation (NavIC) L-Band Geo Synchronous Satellite's Direct Signal and Multipath Signals

Comparative Analysis of NavIC Multipath Observables for Soil Moisture over Different Field Conditions

Navic Multipath Signal Analysis for Soil Moisture Sensitivity in the Perspective of a Winter Wheat Crop

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