Estimates of surface roughness derived from synthetic aperture radar (SAR) data

1992 ◽  
Vol 30 (2) ◽  
pp. 382-389 ◽  
Author(s):  
D.L. Evans ◽  
T.G. Farr ◽  
J.J. van Zyl
Keyword(s):  
Surface Roughness ◽  
Synthetic Aperture Radar ◽  
Synthetic Aperture ◽  
Sar Data ◽  
Aperture Radar

scholarly journals Estimation of surface roughness in a semiarid region from C-band ERS-1 synthetic aperture radar data

1999 ◽  
Vol 23 (4) ◽  
pp. 903-908 ◽  
Author(s):  
E. E. Sano ◽  
A. R. Huete ◽  
M. S. Moran
Keyword(s):  
Surface Roughness ◽  
Synthetic Aperture Radar ◽  
Radar Data ◽  
Synthetic Aperture ◽  
Semiarid Region ◽  
Wet Season ◽  
Synthetic Aperture Radar Data ◽  
Sar Data ◽  
Semiarid Rangeland ◽  
Aperture Radar

In this study, we investigated the feasibility of using the C-band European Remote Sensing Satellite (ERS-1) synthetic aperture radar (SAR) data to estimate surface soil roughness in a semiarid rangeland. Radar backscattering coefficients were extracted from a dry and a wet season SAR image and were compared with 47 in situ soil roughness measurements obtained in the rocky soils of the Walnut Gulch Experimental Watershed, southeastern Arizona, USA. Both the dry and the wet season SAR data showed exponential relationships with root mean square (RMS) height measurements. The dry C-band ERS-1 SAR data were strongly correlated (R² = 0.80), while the wet season SAR data have somewhat higher secondary variation (R² = 0.59). This lower correlation was probably provoked by the stronger influence of soil moisture, which may not be negligible in the wet season SAR data. We concluded that the single configuration C-band SAR data is useful to estimate surface roughness of rocky soils in a semiarid rangeland.

A test of airborne, side-looking synthetic-aperture radar in central Newfoundland for geological reconnaissance

1991 ◽  
Vol 28 (2) ◽  
pp. 257-265 ◽  
Author(s):  
D. F. Graham ◽  
D. R. Grant
Keyword(s):  
Surface Roughness ◽  
Synthetic Aperture Radar ◽  
Three Dimensional ◽  
Synthetic Aperture ◽  
Structural Elements ◽  
Terrain Classification ◽  
Regional Trends ◽  
Valuable Complement ◽  
Wide Swath ◽  
Aperture Radar

Side-looking, C-band synthetic-aperture radar (SAR) penetrates cloud and fog, and operates day or night, to produce pseudo-three-dimensional terrain images with enhanced topography and surface roughness. The images, which have a 20 m resolution and cover large areas, have been used to map the regional trends, patterns of lineaments, and terrain types over a 6200 km2 area of complex lithology, structure, and drift cover. Four lineament classes are differentiated. Glacial trends are clear, and bedrock structures (faults, fractures, joints, foliation, and folded bedding) with relief expression at the surface show through the drift as lineaments. They accurately reproduce most known features when compared with bedrock and Quatenary geology maps. Hitherto unrecognized structural elements are revealed. Tones and textures reflect minute surface roughness variations useful in terrain classification. SAR wide-swath-mode imagery is thus a valuable complement to aerial photography, and is superior in revealing hummocky moraine, ribbed moraine, boulder fields and stony till. Wider use of this imagery is encouraged.

Multi-Temporal Synthetic Aperture Radar Data for Paddy Crop Area Estimation in Eastern part of Godavari Delta, Andhra Pradesh, India.

2020 ◽  
Vol 8 (3) ◽  
pp. 208-218
Author(s):  
S.K. Tiwari ◽  
Prasada Rao G
Keyword(s):  
Synthetic Aperture Radar ◽  
Cloud Cover ◽  
Andhra Pradesh ◽  
Synthetic Aperture ◽  
Crop Acreage ◽  
The Third ◽  
Godavari Delta ◽  
Sar Data ◽  
Paddy Crop ◽  
Aperture Radar

In the present study, an attempt is made to estimate the area under paddy crop during Rabi, 2013-14 using Microwave satellite data in the eastern part of Godavari delta. Clouds veil nearly the entire sky in both (Kharif & Rabi) seasons of Andhra Pradesh and hinder the estimation of crop acreage through optical satellite sensors. Microwaves can penetrate clouds and be used to detect crops during the day and night, regardless of cloud cover. Radar Imaging SATellite-1 (RISAT-1), microwave sensor, dual-polarization Horizontal-Horizontal (HH), Horizontal-Vertical (HV), Medium Resolution scanSAR Mode (MRS) data (18 m pixel spacing and 37° incidence angle) of three different dates (in December, January, and February) with 25 days interval was used. The backscatter (dB) values of the early, mid, and late-season transplanted stages of paddy crop were used to estimate the paddy crop acreage coupled with ground truth information during different stages of the crop. It was observed that the dB values at the transplanting stage rapidly increased with plant growth in the early season sown areas and mid-season sowed paddy illustrate a dip in dB values in the second date due to change in transplantation and increased backscatter coefficient values in the third date because of crop growth after transplantation. The backscatter signature value of late sowing paddy crop showed first and second dates with high backscatter due to previous crop/vegetation and then a sudden dip in the third date as submerged field ready for transplantation. The dB values of the above stages were used in decision-based classifier to estimate paddy crop acreage. The paddy area was compared at Mandal (sub-district level) estimates observed the significant coefficient of determination (R² = 0.89) between traditional estimates and Synthetic Aperture Radar (SAR) data assessment. This study robustly suggests the utilization of SAR data in agricultural crop monitoring during cloud cover.

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