Validation of MODIS 3 km Resolution Aerosol Optical Depth Retrievals Over Asia
This study evaluates the new Aqua MODIS Dark Target (DT) Collection 6 (C6) Aerosol Optical Depth (AOD) (MYD04_3K) retrieval algorithm at 3 km resolution over Asian countries that have recently experienced severe and increasing air pollution. Retrievals showed generally low accuracy compared with the...
Published in: | Remote Sensing |
---|---|
Main Authors: | , |
Format: | Text |
Language: | English |
Published: |
Multidisciplinary Digital Publishing Institute
2016
|
Subjects: | |
Online Access: | https://doi.org/10.3390/rs8040328 |
id |
ftmdpi:oai:mdpi.com:/2072-4292/8/4/328/ |
---|---|
record_format |
openpolar |
spelling |
ftmdpi:oai:mdpi.com:/2072-4292/8/4/328/ 2023-08-20T03:59:10+02:00 Validation of MODIS 3 km Resolution Aerosol Optical Depth Retrievals Over Asia Janet Nichol Muhammad Bilal agris 2016-04-14 application/pdf https://doi.org/10.3390/rs8040328 EN eng Multidisciplinary Digital Publishing Institute https://dx.doi.org/10.3390/rs8040328 https://creativecommons.org/licenses/by/4.0/ Remote Sensing; Volume 8; Issue 4; Pages: 328 AERONET MODIS 3 km AOD Asia Text 2016 ftmdpi https://doi.org/10.3390/rs8040328 2023-07-31T20:52:24Z This study evaluates the new Aqua MODIS Dark Target (DT) Collection 6 (C6) Aerosol Optical Depth (AOD) (MYD04_3K) retrieval algorithm at 3 km resolution over Asian countries that have recently experienced severe and increasing air pollution. Retrievals showed generally low accuracy compared with the AErosol RObotic NETwork (AERONET), with only 55% of retrievals within the expected error (EE). The uncertainty appears mainly due to systematic overestimation at both low and high AOD levels. This is attributed to under-prediction of surface reflectance, similar to, but more severe than, the C6 DT product at 10-km resolution. This is because MYD04_3K observes more noise in the surface reflectance computations, due to retention of some bright pixels in the retrieval window which would be discarded at 10 km. Greatest uncertainty was observed at urban sites, especially those dominated by coarse aerosols. Results suggest that the DT at 3 km is less reliable than MODIS C6 AOD products at 10 km. Text Aerosol Robotic Network MDPI Open Access Publishing Remote Sensing 8 4 328 |
institution |
Open Polar |
collection |
MDPI Open Access Publishing |
op_collection_id |
ftmdpi |
language |
English |
topic |
AERONET MODIS 3 km AOD Asia |
spellingShingle |
AERONET MODIS 3 km AOD Asia Janet Nichol Muhammad Bilal Validation of MODIS 3 km Resolution Aerosol Optical Depth Retrievals Over Asia |
topic_facet |
AERONET MODIS 3 km AOD Asia |
description |
This study evaluates the new Aqua MODIS Dark Target (DT) Collection 6 (C6) Aerosol Optical Depth (AOD) (MYD04_3K) retrieval algorithm at 3 km resolution over Asian countries that have recently experienced severe and increasing air pollution. Retrievals showed generally low accuracy compared with the AErosol RObotic NETwork (AERONET), with only 55% of retrievals within the expected error (EE). The uncertainty appears mainly due to systematic overestimation at both low and high AOD levels. This is attributed to under-prediction of surface reflectance, similar to, but more severe than, the C6 DT product at 10-km resolution. This is because MYD04_3K observes more noise in the surface reflectance computations, due to retention of some bright pixels in the retrieval window which would be discarded at 10 km. Greatest uncertainty was observed at urban sites, especially those dominated by coarse aerosols. Results suggest that the DT at 3 km is less reliable than MODIS C6 AOD products at 10 km. |
format |
Text |
author |
Janet Nichol Muhammad Bilal |
author_facet |
Janet Nichol Muhammad Bilal |
author_sort |
Janet Nichol |
title |
Validation of MODIS 3 km Resolution Aerosol Optical Depth Retrievals Over Asia |
title_short |
Validation of MODIS 3 km Resolution Aerosol Optical Depth Retrievals Over Asia |
title_full |
Validation of MODIS 3 km Resolution Aerosol Optical Depth Retrievals Over Asia |
title_fullStr |
Validation of MODIS 3 km Resolution Aerosol Optical Depth Retrievals Over Asia |
title_full_unstemmed |
Validation of MODIS 3 km Resolution Aerosol Optical Depth Retrievals Over Asia |
title_sort |
validation of modis 3 km resolution aerosol optical depth retrievals over asia |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2016 |
url |
https://doi.org/10.3390/rs8040328 |
op_coverage |
agris |
genre |
Aerosol Robotic Network |
genre_facet |
Aerosol Robotic Network |
op_source |
Remote Sensing; Volume 8; Issue 4; Pages: 328 |
op_relation |
https://dx.doi.org/10.3390/rs8040328 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/rs8040328 |
container_title |
Remote Sensing |
container_volume |
8 |
container_issue |
4 |
container_start_page |
328 |
_version_ |
1774717360458956800 |