NOAA Assessment of the Oceansat-2 Scatterometer

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1 NOAA Assessment of the Oceansat-2 catterometer eubson oisuvarn Khalil Ahmad Zorana Jelenak Joseph ienkiewicz Paul. Chang 9-11 May 2011 IOVWT Meeting, Annapolis, MD, UA 1

2 Introduction NOAA has been receiving day old OCAT data via IRO dedicated FTP server since eptember 2010 NRT OCAT data flow from IRO to EUMETAT commenced in February ince then EUMETAT has been receives orbits per day. In March 2011 NRT OCAT data flow began at NOAA via EUMETAT dedicated FTP server NOAA is currently receiving all three levels of OCAT data: L1B, L2A and L2B L2A and L2B 50 km WVC Latest data as of February 2011 was used in analysis Near real-time received through EUMETAT Collocation of GDA wind vector was done for L1B (slice) and L2A (composite) igma May 2011 IOVWT Meeting, Annapolis, MD, UA 2

3 OCAT Data Flow and Processing Within KNM JPL TAR EUM EXGAT E erver L1B, and 50km L2A and L2B EUM FTP Data erver TAR FTP erver I TAR OWDP 25km MGDR L2B L3 Web Products NAWIP AWIP NWP Buff Establishe d NAA/JPL In Development not tarted IRO L1B, L2A, L2B Data toring 9-11 May 2011 IOVWT Meeting, Annapolis, MD, UA 3 3

4 L1B 9-11 May 2011 IOVWT Meeting, Annapolis, MD, UA 4

5 ignal & Noise Power Calculates ignal power (echo after noise subtraction) and Noise power from the following formulation Plot as a function of wind speed ignal is below noise winds < 7.5 m/s in a mean! P signal NR P noise s = X = = P P s σ signal noise X s σ NR 0 s s 0 s

6 ignal & Noise Power OCAT QuikCAT Click to edit Master text styles Click to edit Master text styles Third level ignal Power Third level

7 ignal & Noise Power OCAT QuikCAT Click to edit Master text styles Click to edit Master text styles Third level Noise Fourth Power level Low NR ignal Power Third level ~7.5 m/s

8 OCAT QuikCAT 89 % 96 % 11 % 4 %

9 can Angle Dependence Click to edit Master text styles Third level 9-11 May 2011 IOVWT Meeting, Annapolis, MD, UA 9

10 L2A 9-11 May 2011 IOVWT Meeting, Annapolis, MD, UA 10

11 NEW IRO 50km L2A

12 lice & Composite bias Click to edit Master text styles Third level σ 0 comp = X X σ 0 X factor

13 L1B L2A (NOAA) 9-11 May 2011 IOVWT Meeting, Annapolis, MD, UA 13

14 lick to edit Master text styles Third level OCAT wind processor Use QuikCAT wind processor as a starting point Process OCAT data from Level 1B Grid 25 km WVC (L2A)

IRO orbit (50 km) NOAA orbit (25 km) Click to edit Master text styles Click to edit Master text styles Third level Third level IRO derived WVC index (i,j) from satellite position and velocity vectors

15 IRO orbit (50 km) NOAA orbit (25 km) Click to edit Master text styles Click to edit Master text styles Third level Third level IRO derived WVC index (i,j) from satellite position and velocity vectors (not currently available in routine L1B processing ) Derived WVC index (i,j) by approximation from orbital elements given in L1B attribute parameters, i.e. - Inclination = deg - emi-major axis = km - Eccentricity = Equator crossing longitude (descending node) = varied orbit-by-orbit

16 Composite igma0 and TD Click to edit Master text styles Third level σ 01 σ 02 σ 03 σ 0 comp = X X σ We calculate standard deviation of each igma0 from the following formulation σ TD = 0 1 N X σ X 0 0 σ 0 comp 2

17 FORE LOOK AFT LOOK V-POL igma0 Residual Click to edit Master text styles Click to edit Master text styles Bias Third level Fourth level Third level 9-11 May 2011 IOVWT Meeting, Annapolis, MD, UA 17

18 V-POL igma0 Residual Bias We normalize the residual bias by the standard deviation calculated above: bias (Normalized) FORE LOOK AFT LOOK Click to edit Master text styles Click to edit Master text styles Third level Third level σ = 0 comp norm 0 GMF σ TD 9-11 May 2011 IOVWT Meeting, Annapolis, MD, UA 18

19 Residual Bias after Normalization Click to edit Master text styles Third level 9-11 May 2011 IOVWT Meeting, Annapolis, MD, UA 19

20 ummary and Conclusions OCAT data has been flowing to NOAA in near real-time via EUMETAT since March 2011 OCAT L1B/L2A investigation shows: High wind retrievals from OCAT would be valuable ignal-to-noise ratio is too low at low wind speeds < ~ 7.5 m/s igma0 residual biases are significantly high at low wind speeds igma0 are dependent on antenna scan position and ascending/descending orbit NOAA is developing enhanced L2A product from IRO s L1B 25 km WVC grid L2A product will contain standard deviation of composite igma0 Is proving to be useful parameter in definition of objective function normalization during retrieval process 9-11 May 2011 IOVWT Meeting, Annapolis, MD, UA 20

Simulation of Brightness Temperatures for the Microwave Radiometer (MWR) on the Aquarius/SAC-D Mission. Salman S. Khan M.S. Defense 8 th July, 2009

Simulation of Brightness Temperatures for the Microwave Radiometer (MWR) on the Aquarius/SAC-D Mission Salman S. Khan M.S. Defense 8 th July, 2009 Outline Thesis Objective Aquarius Salinity Measurements