Rapid wind–terrain correction for wildfire simulations

2021 ◽  
Author(s):  
James Hilton ◽  
Nikhil Garg
Keyword(s):  
Terrain Correction

scholarly journals 3-D Cauchy-type integrals for terrain correction of gravity and gravity gradiometry data

2013 ◽  
Vol 194 (1) ◽  
pp. 249-268 ◽  
Author(s):  
Michael S. Zhdanov ◽  
Xiaojun Liu
Keyword(s):  
Terrain Correction ◽  
Cauchy Type ◽  
Gravity Gradiometry ◽  
Cauchy Type Integrals

scholarly journals Necessity of Terrain Correction in Magnetotelluric Data Recorded from Garhwal Himalayan Region, India

Geosciences ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 482
Author(s):  
Dharmendra Kumar ◽  
Arun Singh ◽  
Mohammad Israil
Keyword(s):  
Real Data ◽  
Terrain Correction ◽  
Himalayan Region ◽  
General Character ◽  
Period Range ◽  
Magnetotelluric Data ◽  
Heterogeneous Models ◽  
Corrected Data ◽  
Terrain Corrections ◽  
And Inversion

The magnetotelluric (MT) method is one of the useful geophysical techniques to investigate deep crustal structures. However, in hilly terrains, e.g., the Garhwal Himalayan region, due to the highly undulating topography, MT responses are distorted. Such responses, if not corrected, may lead to the incorrect interpretation of geoelectric structures. In the present paper, we implemented terrain corrections in MT data recorded from the Garhwal Himalayan Corridor (GHC). We used AP3DMT, a 3D MT data modeling and inversion code written in the MATLAB environment. Terrain corrections in the MT impedance responses for 39 sites along the Roorkee–Gangotri profile in the period range of 0.01 s to 1000 s were first estimated using a synthetic model by recording the topography and locations of MT sites. Based on this study, we established the general character of the terrain and established where terrain corrections were necessary. The distortion introduced by topography was computed for each site using homogenous and heterogeneous models with actual topographic variations. Period-dependent, galvanic and inductive distortions were observed at different sites. We further applied terrain corrections to the real data recorded from the GHC. The corrected data were inverted, and the inverted model was compared with the corresponding inverted model obtained with uncorrected data. The modification in electrical resistivity features in the model obtained from the terrain-corrected response suggests the necessity of terrain correction in MT data recorded from the Himalayan region.

scholarly journals Micro-Topography Mapping through Terrestrial LiDAR in Densely Vegetated Coastal Environments

2021 ◽  
Vol 10 (10) ◽  
pp. 665
Author(s):  
Xukai Zhang ◽  
Xuelian Meng ◽  
Chunyan Li ◽  
Nan Shang ◽  
Jiaze Wang ◽  
...  
Keyword(s):  
Correction Factor ◽  
Laser Scanning ◽  
Accuracy Assessment ◽  
Correction Method ◽  
Terrain Correction ◽  
Surface Model ◽  
Coastal Environments ◽  
Terrestrial Lidar ◽  
Dense Vegetation ◽  
Micro Topography

Terrestrial Light Detection And Ranging (LiDAR), also referred to as terrestrial laser scanning (TLS), has gained increasing popularity in terms of providing highly detailed micro-topography with millimetric measurement precision and accuracy. However, accurately depicting terrain under dense vegetation remains a challenge due to the blocking of signal and the lack of nearby ground. Without dependence on historical data, this research proposes a novel and rapid solution to map densely vegetated coastal environments by integrating terrestrial LiDAR with GPS surveys. To verify and improve the application of terrestrial LiDAR in coastal dense-vegetation areas, we set up eleven scans of terrestrial LiDAR in October 2015 along a sand berm with vegetation planted in Plaquemines Parish of Louisiana. At the same time, 2634 GPS points were collected for the accuracy assessment of terrain mapping and terrain correction. Object-oriented classification was applied to classify the whole berm into tall vegetation, low vegetation and bare ground, with an overall accuracy of 92.7% and a kappa value of 0.89. Based on the classification results, terrain correction was conducted for the tall-vegetation and low-vegetation areas, respectively. An adaptive correction factor was applied to the tall-vegetation area, and the 95th percentile error was calculated as the correction factor from the surface model instead of the terrain model for the low-vegetation area. The terrain correction method successfully reduced the mean error from 0.407 m to −0.068 m (RMSE errors from 0.425 m to 0.146 m) in low vegetation and from 0.993 m to −0.098 m (RMSE from 1.070 m to 0.144 m) in tall vegetation.

Terrain correction for gravity measurements, using a digital terrain model (DTM)

1987 ◽  
Vol 24 (2) ◽  
pp. 109-124 ◽  
Author(s):  
A.C.R. Ketelaar
Keyword(s):  
Digital Terrain Model ◽  
Terrain Correction ◽  
Terrain Model ◽  
Digital Terrain ◽  
Gravity Measurements

Computer technology of terrain correction evaluation in gravity survey

2003 ◽  
Author(s):  
A. Dolgal ◽  
S. Bychkov ◽  
V. Antipin
Keyword(s):  
Computer Technology ◽  
Terrain Correction ◽  
Gravity Survey
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