MODIS derived K490 datasets

• Other Authors: Commonwealth of Australia (Geoscience Australia) (distributor), Commonwealth of Australia (Geoscience Australia) (pointOfContact), Commonwealth of Australia (Geoscience Australia) (owner), EGD (hasAssociationWith), Geoscience Australia (publisher), Huang, Z. (author), Manager Client Services (custodian), U56061 (custodian)
• Format: Dataset
• Language: unknown
• Published: Geoscience Australia
• Subjects: oceans; Marine Data; remote sensing; NERP Marine Biodiversity Hub; marine; NERP; Marine Geoscience; EARTH SCIENCES; GEOLOGY; Published_External; Southern Ocean
• Online Access: https://researchdata.edu.au/modis-derived-k490-datasets/1236199; https://pid.geoscience.gov.au/dataset/ga/77007

Maintenance and Update Frequency: notPlanned Statement: The K490 datasets are derived products of MODIS (Aqua) images. SeaDAS (version 6.1) was used to process the MODIS data from raw to L3 products. SeaDAS provides several algorithms for K490 products. The algorithm used here is the standard algorithm (OBPG) (Werdell, 2005). The sequences of processing included: 1. raw - L1A, 2. L1A - L1B, 3. L1B - L2, 4. L2 - L3 (spatial) binning, and 5. L3 binning to L3 time-binning. The first four steps were applied to all individual (daily) raw images. After completing the above steps for one-month-worth images (around 300 images), in the fifth step, four weekly images were generated: 1. week1: from the 1st to the 7th of the month; 2. week2: from the 8th to the 14th of the month; 3. week3: from the 15th to the 21st of the month; 4. week4: from the 22nd to the last day of the month. The four weekly images were exported as HDF files, then imported into ArcGIS and converted into ArcInfo grids. Next, the four grids were mosaiced into a monthly image using the averaging method. The above processes were repeated to generate the final 36 monthly datasets between 2009 and 2011. Werdell, P.J., 2005. OceanColor K490 algorithm evaluation. http://oceancolor.gsfc.nasa.gov/REPROCESSING/SeaWiFS/R5.1/k490_update.html (accessed 10/10/2011). The datasets measure the K490 parameter (Downwelling diffuse attenuation coefficient at 490 nm, a turbidity parameter) of Australian oceans. They are derived products from MODIS (aqua) images using NASA's SeaDAS image processing software. The extent of the datasets covers the entire Australian EEZ and surrounding waters (including the southern ocean). The spatial resolution of the datasets is 0.01 dd. The datasets contain 36 monthly k490 layers between 2009 and 2011. The unit of the datasets is 1/m.