Atmospheric Correction and Vicarious Calibration of Oceansat-1 Ocean Color Monitor (OCM) Data in Coastal Case 2 Waters

Remote Sensing

Padmanava Dash²  Nan Walker³  Deepak Mishra¹  Eurico D’Sa³ 

[1] Department of Geosciences, Northern Gulf Institute, and Geosystems Research Institute, Mississippi State University, Mississippi State, MS 39762, USA; E-Mail:;Department of Biology, Jackson State University, Jackson, MS 39217, USA;Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA 70803, USA; E-Mails:

关键词: OCM;    SeaWiFS;    atmospheric correction;    vicarious calibration;    Case 2 water;   

DOI  :  10.3390/rs4061716

来源: mdpi

【 摘 要 】

The Ocean Color Monitor (OCM) provides radiance measurements in eight visible and near-infrared bands, similar to the Sea-viewing Wide Field-of-View Sensor (SeaWiFS) but with higher spatial resolution. For small- to moderate-sized coastal lakes and estuaries, where the 1 × 1 km spatial resolution of SeaWiFS is inadequate, the OCM provides a good alternative because of its higher spatial resolution (240 × 360 m) and an exact repeat coverage of every two days. This paper describes a detailed step-by-step atmospheric correction procedure for OCM data applicable to coastal Case 2 waters. This development was necessary as accurate results could not be obtained for our Case 2 water study area in coastal Louisiana with OCM data by using existing atmospheric correction software packages. In addition, since OCM-retrieved radiances were abnormally low in the blue wavelength region, a vicarious calibration procedure was developed. The results of our combined vicarious calibration and atmospheric correction procedure for OCM data were compared with the results from the SeaWiFS Data Analysis System (SeaDAS) software package outputs for SeaWiFS and OCM data. For Case 1 waters, our results matched closely with SeaDAS results. For Case 2 waters, our results demonstrated closure with in situ radiometric measurements, while SeaDAS produced negative normalized water leaving radiance (_nL_w) and remote sensing reflectance (R_rs). In summary, our procedure resulted in valid _nL_w and R_rs values for Case 2 waters using OCM data, providing a reliable method for retrieving useful _nL_w and R_rs values which can be used to develop ocean color algorithms for in-water substances (e.g., pigments, suspended sediments, chromophoric dissolved organic matter, etc.) at relatively high spatial resolution in regions where other software packages and sensors such as SeaWiFS and Moderate Resolution Imaging Spectrometer (MODIS) have proven unsuccessful. The method described here can be applied to other sensors such as OCM-2 or other Case 2 water areas.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.