Authors / CoAuthors
Abstract
<b>This record was retired 29/03/2022 with approval from S.Oliver as it has been superseded by eCat 132317 GA Landsat 8 OLI/TIRS Analysis Ready Data Collection 3</b> The PQ25 product facilitates interpretation and processing of Surface Reflectance (SR-N/NT), Fractional Cover 25 (FC25) and all derivative products. PQ25 is an assessment of each image pixel to determine if it is an unobscured, unsaturated observation of the Earth's surface and also whether the pixel is represented in each spectral band. The PQ product allows users to produce masks which can be used to exclude pixels which don't meet their quality criteria from analysis . The capacity to automatically exclude such pixels is essential for emerging multi-temporal analysis techniques that make use of every quality assured pixel within a time series of observations. Users can choose to process only land pixels, or only sea pixels depending on their analytical requirements, leading to enhanced computationally efficient.
Product Type
dataset
eCat Id
102290
Contact for the resource
Owner
Cnr Jerrabomberra Ave and Hindmarsh Dr
Symonston
ACT
2609
Australia
Custodian
Cnr Jerrabomberra Ave and Hindmarsh Dr
Symonston
ACT
2609
Australia
Point of contact for the resource
Point of contact
Cnr. Jerrabomberra Ave. and Hindmarsh Dr.
Symonston
ACT
2609
Australia
Point of contact
Cnr. Jerrabomberra Ave. and Hindmarsh Dr.
Symonston
ACT
2609
Australia
Point of contact
Cnr. Jerrabomberra Ave. and Hindmarsh Dr.
Symonston
ACT
2609
Australia
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr
Symonston
ACT
2609
Australia
Point of contact
Cnr. Jerrabomberra Ave. and Hindmarsh Dr.
Symonston
ACT
2609
Australia
Point of contact
Cnr. Jerrabomberra Ave. and Hindmarsh Dr.
Symonston
ACT
2609
Australia
Keywords
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- NCI
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- Satellite imagery
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- Landsat 5
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- Landsat 7
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- Landsat 8
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- Earth Observations from Space
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- rs0
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- Pixel Quality
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- Data
- Australian and New Zealand Standard Research Classification: Fields of Research
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- Earth Sciences
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- Published_External
Publication Date
2016-06-17T00:00:00
Creation Date
Security Constraints
Legal Constraints
Status
superseded
Purpose
Maintenance Information
asNeeded
Topic Category
geoscientificInformation
Series Information
Lineage
As Landsat Imagery becomes more readily available, there has been a rapid increase in the amount of analyses undertaken by researchers around the globe. Most researchers use some form of quality masking schema in order to remove undesirable pixels from analysis, whether that be cloud, cloud shadow, observations over the ocean, or saturated pixels. In the past, researchers would reject partly cloud-affected scenes in favour of cloud-free scenes. However, Landsat time series analysis using all cloud-free pixels has become a valuable technique and has increased the demand for automation of cloud, cloud shadow and saturation detection. Emergency response applications such as flood mapping typically have to contend with individual cloud affected scenes and therefore rely on effective cloud and cloud shadow removal techniques. The PQ25 product combines established algorithms that detect clouds including the Automated Cloud Cover Assessment (ACCA) (Irish et al. 2006) and Function of mask (Fmask) (Zhu and Woodcock 2012) . ACCA is already widely used within the remote sensing community; it is fast and relatively accurate. Fmask on the other hand is newer, but is rapidly becoming more established, and can provide a more accurate cloud mask than ACCA in certain cloud environments. The sensor saturation flagging protocols developed for the Web Enabled Landsat Data (WELD) product as described in Roy et al. (2011) are used to flag sensor saturation. The PQ25 product has similarities to the QAB layer packaged with OLI data, however it uses additional algorithms to detect cloud and cloud shadow, and is available for Landsats 5, 7 and 8.
Parent Information
GA Earth Observation - Data
UUID - 3a2cd509-0e82-4381-98c7-522756da533b
Extents
[-45.00, -10.00, 108.00, 155.00]
Reference System
GDA94 / Australian Albers (EPSG: 3577)
Spatial Resolution
Service Information
Associations
Source Information
Please refer to the lineage section.