Use of Ground‐Penetrating Radar to Determine the Depositional Environment of Glacial Deposits in Southern New Hampshire

1994 ◽  
Author(s):  
Joseph D. Ayotte
Keyword(s):  
New Hampshire ◽  
Ground Penetrating Radar ◽  
Depositional Environment ◽  
Glacial Deposits ◽  
Ground Penetrating

scholarly journals GROUND-PENETRATING RADAR IMAGING TECHNIQUES APPLIED IN 3D ENVIRONMENT: EXAMPLE IN INACTIVE DUNES

2014 ◽  
Vol 32 (2) ◽  
pp. 273 ◽  
Author(s):  
David Lopes de Castro ◽  
João Andrade dos Reis Júnior ◽  
Washington Luiz Evangelista Teixeira ◽  
Victor De Albuquerque Silva ◽  
Francisco Pinheiro Lima Filho
Keyword(s):  
Ground Penetrating Radar ◽  
Depositional Environment ◽  
Imaging Techniques ◽  
Velocity Model ◽  
Imaging Processing ◽  
Frequency Domains ◽  
3D Gpr ◽  
Ground Penetrating ◽  
Radar Facies ◽  
Stratigraphic Sequences

ABSTRACT. The increased use of Ground-Penetrating Radar (GPR) in several areas of knowledge has introduced an impressive number of new methodologicalprocedures, adapted from other areas, such as seismic reflection, or developed specifically for the GPR. A summary of the advances in acquisition, processing andinterpretation of GPR data is presented in this paper. Some of the techniques were applied to a 3D GPR survey in a study area, whose substrate is composed bysedimentary sequences of paleodunes or inactive dunes, located in the outer courtyard of the Department of Geology (DEGEO) of the Universidade Federal do Rio Grandedo Norte (UFRN), Brazil. A GPR cube was generated from a regular grid of GPR in-lines and cross-lines, spaced 0.5 m. A filtering routine was applied. For eachprocessing step, the changes in the signal content in the time and frequency domains were analyzed. Common midpoint (CMP) sections and hyperbolas of buried pipesconstrained the construction of a subsurface velocity model, allowing the migration and time/depth conversion of the radargrams. Analysis of instantaneous, amplitude,and geometrical attributes and concepts of seismic stratigraphy were applied in the migrated GPR cube to define five stratigraphic sequences and their paleo-reliefs.Based on the radar facies internal geometry, some considerations were established about the depositional environment of the surveyed area.Keywords: GPR, 3D imaging, processing, attribute analysis.RESUMO. A expansão do uso do GPR nas mais diversas áreas do conhecimento tem contribuído para o desenvolvimento de novos procedimentos metodológicos,decorrentes da adaptação de outros métodos geofísicos, principalmente a sísmica de reflexão, ou desenvolvidos especialmente para o GPR. Uma síntese dos avanços nas etapas de aquisição, processamento e interpretação é descrita no presente artigo. Algumas das técnicas analisadas foram aplicadas em dados GPR obtidos em umlevantamento realizado segundo uma malha retangular, em uma área de estudo situada no interior do campus da Universidade Federal do Rio Grande do Norte (UFRN).O substrato imageado é constituído por camadas de sedimentos arenosos siliciclásticos, de origem eólica costeira, depositados sobre rochas do Grupo Barreiras. Um volume GPR foi gerado a partir de uma malha regular de linhas longitudinais e transversais, espaçadas de 0,5 m. Uma rotina de filtragem dos dados GPR é proposta, sendo as alterações no conteúdo do sinal eletromagnético (EM) analisadas nos domínios do tempo e frequência para cada etapa do processamento. Seções de ponto médio comum (CMP) e hipérboles de tubulações soterradas permitiram a confecção de um modelo de velocidades da subsuperfície e a migração e conversão tempo/profundidade dos radargramas. Análise de atributos instantâneos, de amplitude e geométricos, além de técnicas de interpretação sismoestratigráficas foram aplicadas no volume GPR migrado para definir cinco sequências estratigráficas e seus paleorelevos. Com base nas geometrias internas das radarfácies, foram tecidasalgumas considerações sobre a geometria e arquitetura dos depósitos investigados.Palavras-chave: GPR, imageamento 3D, processamento, análise de atributos.

REFLECTION COEFFICIENT OF AN ELECTROMAGNETIC WAVE IN CONDUCTIVE MEDIA

2018 ◽  
pp. 100-106
Author(s):  
M. S. Sudakova ◽  
M. L. Vladov ◽  
M. R. Sadurtdinov
Keyword(s):  
Reflection Coefficient ◽  
Ground Penetrating Radar ◽  
Electromagnetic Waves ◽  
Water Contamination ◽  
Survey Design ◽  
Direct And Inverse Problems ◽  
The Difference ◽  
Ground Penetrating ◽  
Ideal Dielectric

Within the ground penetrating radar bandwidth the medium is considered to be an ideal dielectric, which is not always true. Electromagnetic waves reflection coefficient conductivity dependence showed a significant role of the difference in conductivity in reflection strength. It was confirmed by physical modeling. Conductivity of geological media should be taken into account when solving direct and inverse problems, survey design planning, etc. Ground penetrating radar can be used to solve the problem of mapping of halocline or determine water contamination.

Deteksi Bentuk Objek Bawah Tanah Menggunakan Pengolahan Citra B-Scan pada Ground Penetrating Radar (GPR)

2017 ◽  
Vol 3 (1) ◽  
pp. 73-83
Author(s):  
Rahmayati Alindra ◽  
Heroe Wijanto ◽  
Koredianto Usman
Keyword(s):  
Signal Processing ◽  
Ground Penetrating Radar ◽  
Post Processing ◽  
Data Survey ◽  
Ground Penetrating

Ground Penetrating Radar (GPR) adalah salah satu jenis radar yang digunakan untuk menyelidiki kondisi di bawah permukaan tanah tanpa harus menggali dan merusak tanah. Sistem GPR terdiri atas pengirim (transmitter), yaitu antena yang terhubung ke generator sinyal dan bagian penerima (receiver), yaitu antena yang terhubung ke LNA dan ADC yang kemudian terhubung ke unit pengolahan data hasil survey serta display sebagai tampilan output-nya dan post  processing untuk alat bantu mendapatkan informasi mengenai suatu objek. GPR bekerja dengan cara memancarkan gelombang elektromagnetik ke dalam tanah dan menerima sinyal yang dipantulkan oleh objek-objek di bawah permukaan tanah. Sinyal yang diterima kemudian diolah pada bagian signal processing dengan tujuan untuk menghasilkan gambaran kondisi di bawah permukaan tanah yang dapat dengan mudah dibaca dan diinterpretasikan oleh user. Signal processing sendiri terdiri dari beberapa tahap yaitu A-Scan yang meliputi perbaikan sinyal dan pendektesian objek satu dimensi, B-Scan untuk pemrosesan data dua dimensi  dan C-Scan untuk pemrosesan data tiga dimensi. Metode yang digunakan pada pemrosesan B-Scan salah satunya adalah dengan  teknik pemrosesan citra. Dengan pemrosesan citra, data survey B-scan diolah untuk didapatkan informasi mengenai objek. Pada penelitian ini, diterapkan teori gradien garis pada pemrosesan citra B-scan untuk menentukan bentuk dua dimensi dari objek bawah tanah yaitu persegi, segitiga atau lingkaran. 

Sign in / Sign up

Export Citation Format

Share Document