Extension of the QuikSCAT Sea Ice Extent Data Set with OSCAT and ASCAT Data

• Main Author: Hill, Jordan Curtis
• Format: Text
• Language: unknown
• Published: BYU ScholarsArchive 2017
• Subjects: remote sensing; sea ice; OSCAT; ASCAT; cryosphere; Electrical and Computer Engineering; Sea ice
• Online Access: https://scholarsarchive.byu.edu/etd/6320; https://scholarsarchive.byu.edu/context/etd/article/7320/viewcontent/etd9144.pdf

Polar sea ice measurements are an important contribution to global climate models. Passive and active microwave remote sensing instruments are used to track global trends in polar sea ice growth and retreat from day to day. A scatterometer sea ice extent data set is valuable for comparison with other radiometer data sets and ground based measurements. This scatterometer sea ice record began with the NASA Scatterometer (NSCAT) and continued with the Quick Scatterometer (QuikSCAT) data set. The Ku-band Oceansat-2 scatterometer (OSCAT) is very similar to the Quick Scatterometer, which operated from 1999 to 2009. OSCAT continues the Ku-band scatterometer data record through 2014 with an overlap of eighteen days with QuikSCATs mission in 2009. This thesis discusses a particular climate application of the time series for sea ice extent observation. In this thesis, a QuikSCAT sea ice extent algorithm is modified for OSCAT. Gaps in OSCAT data are accounted for using a reverse time processing approach. The data gaps are filled in to support sea ice extent mapping. The data set is validated with overlapping data from QuikSCAT as well as the sea ice extent data set calculated from Special Sensor Microwave Imager data by the NASA Team algorithm.Data from the Advanced Scatterometer (ASCAT), which operates at C-band, are processed using a Bayesian classification algorithm for a stand-alone C-band sea ice extent product to continue scatterometer sea ice extent observation past 2014. ASCAT azimuth dependence data is developed for use as a parameter in the ASCAT sea ice extent algorithm. Image dilation and erosion techniques are employed to smooth the sea ice edge and correct misclassifications. ASCAT sea ice extent data is validated to overlapping OSCAT data.