Mission
SeaWinds on QuikSCAT measures backscatter from the ocean surface (sigma0) used to derive vector wind stress as well as wind speed and direction. Launched in June 19, 1999, QuikSCAT was originally intended to be a 'quick recovery' mission to fill the gap created by the unexpected failure of the NASA scatterometer (NSCAT). Fortunately, QuikSCAT has surpassed its life expectancy and continues to provide reliable and valuable ocean surface wind vector measurements. These measurements are widely used for scientific research over a range of topics including oceanography, meteorology, sea ice, land-based studies, and wind energy. They also serve various needs of the private sector, educational community, and government.

Announcements

The SeaWinds on QuikSCAT and ADEOS-II Multi-Algorithm Surface Wind Stress product has been removed as of April, 2007.

QuikSCAT Follow-on Mission Concept Study (JPL Publication 08-18, April 2008).
To continue to meet the Nation's need for operational ocean surface vector winds (OSVW) observations beyond QuikSCAT, the National Oceanic and Atmospheric Administration (NOAA) tasked the Jet Propulsion Laboratory (JPL) to design and provide costs for a set of QuikSCAT Follow-On mission options. Three scenarios were examined: 1) a QuikSCAT Replacement mission with capabilities equivalent to QuikSCAT, 2) a next-generation Extended Ocean Vector Winds Mission (XOVWM), as recommended in the National Research Council's decadal survey to provide significantly improved all-weather, all-wind, high spatial resolution measurements, and 3) an XOVWM Constellation consisting of two XOVWM observatories to provide improved temporal resolution. In parallel, NOAA asked its users to provide a quantitative assessment of each option's benefit to NOAA. This report presents the JPL design, risk assessment, and cost for each of the three options, together with a summary of the NOAA users' benefit assessment.

Operational Satellite Ocean Surface Vector Winds Project (NOAA, February 2008).
Satellite ocean surface vector wind (OSVW) data has revolutionized operational marine weather warnings, analyses, and forecasting. To maintain the significant improvements in operational weather forecasting and warning capability that have been realized from QuikSCAT OSVW data requires continuity of the OSVW data stream at a level that is equivalent to or better than that provided today by QuikSCAT. This report documents the results of the user impact study conducted to evaluate the impacts of a QuikSCAT equivalent and an advanced next-generation OSVW (XOVWM) follow-on mission on the marine weather warning and forecasting functions of the National Oceanic and Atmospheric Administration (NOAA). A significant result of this study is that the XOVWM mission would greatly enhance the detection and warning capability across a wide range of weather phenomena for nearly all of the National Weather Service's coastal, offshore, high seas, and Great Lakes marine areas of responsibility. An XOVWM capability would yield significant benefits over a QuikSCAT equivalent capability in the forecast and warning program with respect to extratropical cyclones, tropical cyclones, coastal regions, and the Great Lakes. Other information and reports related to the NOAA operational satellite OSVW concept can be downloaded here.

Documentation
BYU Sigma-0 User's Manual

QuikSCAT Level 2B 25/12.5 km User's Guide

QuikSCAT Level 3 User's Guide

QuikSCAT Mission

NRT R-MGDR OWV User's Guide

Frequently Asked Questions
SeaWinds on QuikSCAT FAQ's

Q: Why can't I find today's Level 2B or Level 3 QuikSCAT data online? These products require rigorous processing, and therefore are not provided on the same day that QuikSCAT retrieves its data. At minimum, there is a 24 hour delay due to data retrieval and processing of Level 2B and Level 3 products. In addition, the products are ingested to public archive in "batches" of several days (usually 3 or 4 days). Therefore, it is not unusual to see today's data take 4 to 5 days to appear on our public download servers, where the best case scenario is a 24 hour delay.

A: If you absolutely need access to near-real-time (NRT) wind vector data, PO.DAAC provides an "unofficial" level 2 product (similar to Level 2B; not gridded) that produces QuikSCAT wind vectors from swaths of the most recent orbital revolution, where the delay from real-time is approximately 90-150 minutes behind QuikSCAT's current position. It is important to note, however, that this data is not vetted, and is intended for operational use only. Unlike the Level 2B product, the NRT data is stored in flat binary files, and the data files are organized according to time, not orbital revolutions. The NRT data, along with more information containing sample read software and documentation, can be accessed at the following location: ftp://podaac.jpl.nasa.gov/near_real_time/ocean_wind/quikscat

Related Publications
Ashcraft, I.S. and D.G. Long, 2000. SeaWinds Views Greenland, Proc. Int. Geosci. Rem. Sens. Sym., Honolulu, Hawaii, 6-10 July 2000.

Dunbar, R.S., S.V. Hsiao, and B.H. Lambrigtsen, Science Algorithm Specifications for the NASA Scatterometer Project, JPL D-5610 (597-521), Vol. 1 (Sensor Algorithms) and Vol. 2 (Geophysical Algorithms). Issued May 1988, last updated November 1991.

Dunbar, R.S., T. Lungu, B. Weiss, B. Stiles, J. Huddleston, P.S. Callahan, G. Shirtliffe, K.L. Perry, C. Hsu, C. Mears, F. Wentz, D. Smith, September, 2006. QuikSCAT Science Data Product User's Manual, Version 3.0, JPL Document D-18053 - Rev A, Jet Propulsion Laboratory, Pasadena, CA.

Freilich, M.H., and R.S. Dunbar, "A Preliminary C-Band Scatterometer Model Function for the ERS-1 AMI Instrument," Proceedings of the First ERS-1 Symposium: Space at the Service of our Environment, Cannes, 4-6 November 1992, ESA SP-359, European Space Agency, Paris.

Long, D.G., 2000. A QuikSCAT/SeaWinds Sigma-0 Browse Product, Version 2.0, Brigham Young University, Provo, UT.

Long, D.G. and M.R. Drinkwater, 1999. Cryosphere Applications of NSCAT Data, IEEE Trans. on Geoscience and Remote Sensing, Vol. 37, No. 3, pp. 1671-1684

Huddleston, J.N. and B.W. Stiles, 2000. Multidimensional Histogram (MUDH) Rain Flag Product Description, Version 2.1, Jet Propulsion Laboratory, Pasadena, CA.

Perry, K.L., October, 2001. SeaWinds on QuikSCAT Level 3 Daily, Gridded Ocean Wind Vectors (JPL SeaWinds Project). Version 1.1, JPL Document D-20335, Jet Propulsion Laboratory, Pasadena, CA.

Naderi, F.M., M.H. Freilich, and D.G. Long, "Spaceborne Radar Measurement of Wind Velocity Over the Ocean - An Overview of the NSCAT Scatterometer System," Proc. IEEE, 79, 6, June 1991.

Remund, Q.P. and D.G. Long, 1998. Sea Ice Mapping Algorithm for QuikSCAT and Seawinds, Proc. Int. Geosci. Rem. Sens. Sym., Seattle, Washington, 6-10 July, 1998, pp. 1686-1688.

Remund, Q.P. and D.G. Long, 2000. Iterative Estimation of Antarctic Sea Ice Extent Using SeaWinds Data, Proc. Int. Geosci. Rem. Sens. Sym., Honolulu, Hawaii, 6-10 July 2000

Shaffer, S., R.S. Dunbar, S.V. Hsiao, and D.G. Long, "A Median-Filter-Based Ambiguity Removal Algorithm for NSCAT," IEEE Trans. Geosci. Remote Sens., 29, 1991.

Tang, W., W. T. Liu, and B. W. Stiles, 2004: Evaluation of High-Resolution Ocean Surface Vector Winds Measured by QuikSCAT Scatterometer in Coastal Regions, IEEE, Vol. 42, No. 8, pp. 1762-1769.

Tsai, W., J.E. Graf, C. Winn, J.N. Huddleston, R.S. Dunbar, M.H. Freilich, F.J. Wentz, D.G. Long, and W.L. Jones, "Postlaunch Sensor Verification and Calibration of the NASA Scatterometer," IEEE Trans. Geosci. Remote Sens., vol. 37, pp. 1517-1542, May 1999.

Weiss, B., "Level 1B Data Software Interface Specification (SIS-2)", Internal JPL SeaWinds Project Document 686-644-1 Rev A, JPL Document D-16077, January 2000.

Weiss, B., "Level 2A Data Software Interface Specification (SIS-2)", Internal JPL SeaWinds Project Document 686-644-2 Rev A, JPL Document D-16078, April 2000.

Weiss, B., "Level 2B Data Software Interface Specification (SIS-2)", Internal JPL SeaWinds Project Document 686-644-3 Rev B, JPL Document D-16079, April 2000.

Wentz, F.J., "Climatology of 14 GHz Atmospheric Attenuation," Remote Sensing Systems Tech. Memo 052096, May 1996.

Zhang, A., R.S. Dunbar, S.V. Hsiao, K. Pak, Y. Kim, "Science Algorithm Specifications for SeaWinds," Internal JPL SeaWinds project document, 1996, 1999.