Airborne gravimetry: An investigation of filtering
Low-pass filtering in airborne gravimetry data processing plays a fundamental role in determining the spectral content and amplitude of the free-air anomaly. Traditional filters used in airborne gravimetry, the 6 × 20-s resistor-capacitor (RC) filter and the 300-s Gaussian filter, heavily attenuate...
Main Authors: | , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
1999
|
Subjects: | |
Online Access: | https://doi.org/10.7916/D8F47ZMR |
id |
ftcolumbiauniv:oai:academiccommons.columbia.edu:10.7916/D8F47ZMR |
---|---|
record_format |
openpolar |
spelling |
ftcolumbiauniv:oai:academiccommons.columbia.edu:10.7916/D8F47ZMR 2023-05-15T13:50:01+02:00 Airborne gravimetry: An investigation of filtering Childers, Vicki A. Bell, Robin E. Brozena, John M. 1999 https://doi.org/10.7916/D8F47ZMR English eng https://doi.org/10.7916/D8F47ZMR Airborne gravimetry Gravity--Measurement Geophysics Articles 1999 ftcolumbiauniv https://doi.org/10.7916/D8F47ZMR 2019-04-04T08:06:32Z Low-pass filtering in airborne gravimetry data processing plays a fundamental role in determining the spectral content and amplitude of the free-air anomaly. Traditional filters used in airborne gravimetry, the 6 × 20-s resistor-capacitor (RC) filter and the 300-s Gaussian filter, heavily attenuate the waveband of the gravity signal. As we strive to reduce the overall error budget to the sub-mGal level, an important step is to evaluate the choice and design of the low-pass filter employed in airborne gravimetry to optimize gravity anomaly recovery and noise attenuation. This study evaluates low-pass filtering options and presents a survey-specific frequency domain filter that employs the fast Fourier transform (FFT) for airborne gravity data. This study recommends a new approach to low-pass filtering airborne data. For a given survey, the filter is designed to maximize the target gravity signal based upon survey parameters and the character of measurement noise. This survey-specific low-pass filter approach is applied to two aerogravimetry surveys: one conducted in West Antarctica and the other in the eastern Pacific off the California coast. A reflight comparison with the West Antarctic survey shows that anomaly amplitudes are increased while slightly improving the rms fit between the reflown survey lines when an appropriately designed FFT filter is employed instead of the traditionally used filters. A comparison of the East Pacific survey with high-resolution shipboard gravity data indicates anomaly amplitude improvements of up to 20 mGal and a 49% improvement of the rms fit from 3.99 mGal to 2.04 mGal with the appropriately designed FFT filter. These results demonstrate that substantial improvement in anomaly amplitude and wavelength can be attained by tailoring the filter to the survey. Article in Journal/Newspaper Antarc* Antarctic Antarctica West Antarctica Columbia University: Academic Commons Antarctic West Antarctica Pacific |
institution |
Open Polar |
collection |
Columbia University: Academic Commons |
op_collection_id |
ftcolumbiauniv |
language |
English |
topic |
Airborne gravimetry Gravity--Measurement Geophysics |
spellingShingle |
Airborne gravimetry Gravity--Measurement Geophysics Childers, Vicki A. Bell, Robin E. Brozena, John M. Airborne gravimetry: An investigation of filtering |
topic_facet |
Airborne gravimetry Gravity--Measurement Geophysics |
description |
Low-pass filtering in airborne gravimetry data processing plays a fundamental role in determining the spectral content and amplitude of the free-air anomaly. Traditional filters used in airborne gravimetry, the 6 × 20-s resistor-capacitor (RC) filter and the 300-s Gaussian filter, heavily attenuate the waveband of the gravity signal. As we strive to reduce the overall error budget to the sub-mGal level, an important step is to evaluate the choice and design of the low-pass filter employed in airborne gravimetry to optimize gravity anomaly recovery and noise attenuation. This study evaluates low-pass filtering options and presents a survey-specific frequency domain filter that employs the fast Fourier transform (FFT) for airborne gravity data. This study recommends a new approach to low-pass filtering airborne data. For a given survey, the filter is designed to maximize the target gravity signal based upon survey parameters and the character of measurement noise. This survey-specific low-pass filter approach is applied to two aerogravimetry surveys: one conducted in West Antarctica and the other in the eastern Pacific off the California coast. A reflight comparison with the West Antarctic survey shows that anomaly amplitudes are increased while slightly improving the rms fit between the reflown survey lines when an appropriately designed FFT filter is employed instead of the traditionally used filters. A comparison of the East Pacific survey with high-resolution shipboard gravity data indicates anomaly amplitude improvements of up to 20 mGal and a 49% improvement of the rms fit from 3.99 mGal to 2.04 mGal with the appropriately designed FFT filter. These results demonstrate that substantial improvement in anomaly amplitude and wavelength can be attained by tailoring the filter to the survey. |
format |
Article in Journal/Newspaper |
author |
Childers, Vicki A. Bell, Robin E. Brozena, John M. |
author_facet |
Childers, Vicki A. Bell, Robin E. Brozena, John M. |
author_sort |
Childers, Vicki A. |
title |
Airborne gravimetry: An investigation of filtering |
title_short |
Airborne gravimetry: An investigation of filtering |
title_full |
Airborne gravimetry: An investigation of filtering |
title_fullStr |
Airborne gravimetry: An investigation of filtering |
title_full_unstemmed |
Airborne gravimetry: An investigation of filtering |
title_sort |
airborne gravimetry: an investigation of filtering |
publishDate |
1999 |
url |
https://doi.org/10.7916/D8F47ZMR |
geographic |
Antarctic West Antarctica Pacific |
geographic_facet |
Antarctic West Antarctica Pacific |
genre |
Antarc* Antarctic Antarctica West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica West Antarctica |
op_relation |
https://doi.org/10.7916/D8F47ZMR |
op_doi |
https://doi.org/10.7916/D8F47ZMR |
_version_ |
1766252747053596672 |