190 likes | 338 Views
Update on Metop -B MGVI. Wei Guo and Felix Kogan 01/16/2013. Contents. Verification on geo-location of Metop -B at initial stage Verification on VIS and NIR band s of Metop -B at initial stage Current status of Metop -B NDVI and BT
E N D
Update onMetop-B MGVI Wei Guo and Felix Kogan 01/16/2013
Contents • Verification on geo-location of Metop-B at initial stage • Verification on VIS and NIR bands of Metop-B at initial stage • Current status of Metop-B NDVI and BT • Update on MGVI system VHP GVI composer (avhrr_gvi.exe) • Major change on VHP GVI composer (avhrr_gvi.exe)
Post launch Calibration Figure 1. The seasonal reflectance oscillation is derived from MetOp-A AVHRR visible channel and the MetOP-B AVHRR visible calibration update is performed using the seasonal oscillation trending. Initial On-Orbit Calibration Update of METOP-B AVHRR Solar Channels: The solar bands of Advance Very High Resolution Radiometer (AVHRR) must be calibrated vicariously on orbit, which requires an empirically derived Bi-directional Reflectance Distribution Function (BRDF). For AVHRR on a newly launched satellite, the BRDF will not be available until 18 months after launch. An established method that has been used since NOAA-18 is to use the BRDF derived from an instrument on similar orbit. This has been applied to METOP-B, using the BRDF from METOP-A, and the calibration coefficient updates of 0.951, 1.085, and 1.205 have been recommended for Channels 1, 2, and 3A, respectively. Recently, STAR scientist developed another method of inter-calibration of MetOp-B AVHRR using MetOp-A AVHRR as reference, with the consideration of solar zenith angle effects and sensor zenith angle effects. This method results in the calibration coefficient updates of 0.961and 1.087 for channel 1 and 2, which are consistent with the other method. These initial calibration updates are ready to deliver to OSPO for implementation. (Contact: Tiejun Chang, tiejun.chang@noaa.gov and Xiangqian Wu, xiangqian.wu@noaa.gov)
AVHRR visible channel calibration and consistency NDVI verification Before and after MetOp-B calibration update Initial post-launch calibration coefficient (S) for Metop-B Provided by Xiangqian Wu and Tiejun Chang on 11/23/2012 Rpost= Rpre * S Weekly NDVI from MetOp-A/B
BT4, 2013, week2 METOP-A METOP_B
NDVI, 2013, week2 METOP-A METOP_B
MGVI system VHP GVI composer (avhrr_gvi.exe) • VHP GVI was developed from MGVI • MGVI system is not updated any more, should be replaced by VHP GVI. • VHP GVI algorithm was improved • VHP GVI is easier to maintain (simple procedure) • Difference on GVI product between VHP GVI and MGVI • File name is slightly difference • All other is invisible to operators or end user
What need to do run VHP GVI • Existing VHP GVI (avhrr_gvi.exe) should be able to run for METOP A and B without change • Need: • Configure file • Calibration files (Both pre- and post-launch)
Pre-launch Calibration file [pre-launched calibration, version 3] #Sat, CH Slope_loInt_loSlope_hiInt_hiBreakPoint for NOAA 15 -19,M2, source: http://www.star.nesdis.noaa.gov/smcd/spb/fwu/solar_cal/AVHRR_Prelaunch_CalCoeff.html NK CH1: 0.0567 -2.1590 0.1635 -55.1800 496.6700 NK CH2: 0.0563 -2.1370 0.1630 -55.2900 498.2100 NL CH1: 0.0525 -2.0410 0.1529 -51.9800 497.5300 NL CH2: 0.0513 -1.9480 0.1511 -51.8700 500.3200 NM CH1: 0.0554 -2.2130 0.1627 -55.9900 501.1200 NM CH2: 0.0543 -2.1510 0.1618 -55.9900 500.7300 NN CH1: 0.0545 -2.1790 0.1613 -55.6300 500.5400 NN CH2: 0.0526 -2.0840 0.1584 -55.0700 500.4000 M1 CH1: 0.0536 -2.1099 0.1587 -54.7510 500.6200 M1 CH2: 0.0518 -2.092333 0.1526 -52.8065 503.0000 M2 CH1: 0.0537 -2.1720 0.1587 -54.7800 501.0100 M2 CH2: 0.0545 -2.1670 0.1619 -55.9100 500.4200 NP CH1: 0.0551 -2.1415 0.1625 -55.8630 496.4300 NP CH2: 0.0549 -2.1288 0.1635 -56.4450 500.3700 [END] [Basic information of NOAA AVHRR satellites] [launch date] #sat, launch_date NC: 06/23/1981 NF: 12/12/1984 NH: 09/24/1988 NJ: 12/30/1994 #below was copied from http://www.star.nesdis.noaa.gov/smcd/spb/fwu/solar_cal/AVHRR_Prelaunch_Cal NK: 05/13/1998 NL: 09/21/2000 NM: 06/24/2002 NN: 05/20/2005 M2: 10/19/2006 NP: 02/06/2009 M1: 09/17/2012 [pre-launched calibration, version 2] # current active ! # A= Slope * C + Intercept (reflectance in percentage) #Sat, CH Slope_loInt_loSlope_hiInt_hiBreakPoint for NOAA7,9,11,14, source: http://www2.ncdc.noaa.gov/docs/podug/html/c3/sec3-3.htm NC CH1: 0.1068 -3.4400 0 0 1024 NC CH2: 0.1069 -3.488 0 0 1024 NF CH1: 0.1063 -3.8464 0 0 1024 NF CH2: 0.1075 -3.8770 0 0 1024 NH CH1: 0.0906 -3.730 0 0 1024 NH CH2: 0.0900 -3.390 0 0 1024 NJ CH1: 0.1081 -3.8648 0 0 1024 NJ CH2: 0.1090 -3.6749 0 0 1024
Pre-launch Calibration file #post-launch calibration with the most recent update. #data source= http://www.star.nesdis.noaa.gov/smcd/spb/fwu/homepage/AVHRR/Op_Cal_AVHRR/Op_Cal_AVHRR.html #Sat CH Update Data Center Constant Deg. Rate sin cos Amp. Angle Mean Ratio Slope_loInt_loSlope_hiInt_hi NL CH1: 12/22/2012 09/07/2007 01/26/2013 38.7391 -0.1277% -0.4390 -0.4089 0.5999 42.96 32.98 1.1462 0.06002 -2.314 0.1752 -59.54 NL CH2: 12/22/2012 09/07/2007 01/26/2013 40.5308 -0.1742% -0.1953 -1.3403 1.3544 81.71 32.67 1.3039 0.06687 -2.526 0.1970 -67.62 NM CH1: 09/28/2010 09/24/2010 10/26/2010 39.5504 -0.0995% -0.2193 0.4581 0.5079 -64.42 36.52 1.0351 0.05737 -2.296 0.1684 -57.94 NM CH2: 09/28/2010 09/24/2010 10/26/2010 37.0158 -0.1198% -1.0015 0.0726 1.0041 -4.15 33.37 1.2768 0.06944 -2.726 0.2067 -71.57 NM CH3: 09/28/2010 09/24/2010 10/26/2010 59.2315 -0.2189% 0.0068 1.3414 1.3414 89.71 52.56 1.2728 0.03373 -1.422 0.2364 -103.22 NN CH1: 12/22/2012 11/24/2012 01/26/2013 39.9212 -0.1307% 0.0813 0.6818 0.6866 83.20 36.25 1.0428 0.05631 -2.220 0.1679 -57.74 NN CH2: 12/22/2012 11/24/2012 01/26/2013 38.7307 -0.1483% -0.8954 0.7503 1.1682 -39.96 34.56 1.2325 0.06520 -2.569 0.1956 -68.16 NP CH1: 12/22/2012 12/17/2012 01/26/2013 41.0928 -0.0608% 0.6477 -0.1368 0.6620 -11.93 40.21 0.9401 0.05179 -2.013 0.1528 -52.51 NP CH2: 12/22/2012 12/17/2012 01/26/2013 42.0378 -0.1568% 1.1361 0.6519 1.3099 29.85 39.76 1.0714 0.05881 -2.281 0.1752 -60.47 M2 CH1: 12/22/2012 12/21/2012 01/26/2013 39.1527 -0.0998% -0.1953 -0.3816 0.4287 62.90 36.86 1.0254 0.05508 -2.227 0.1627 -56.17 M2 CH2: 12/22/2012 12/21/2012 01/26/2013 38.5213 -0.1454% 0.4102 -1.0826 1.1577 -69.25 35.19 1.2106 0.06600 -2.623 0.1960 -67.69 M2 CH3: 12/22/2012 12/21/2012 01/26/2013 58.1910 -0.1988% -0.9484 -0.6136 1.1296 32.90 53.64 1.2473 0.03299 -1.356 0.2291 -99.80 M1 CH1: 11/23/2012 11/23/2012 11/23/2012 0.0514560 -2.0255039 0.1523520 -52.5609589 M1 CH2: 11/23/2012 11/23/2012 11/23/2012 0.0563066 -2.2743661 0.1658762 -57.4006653 The parameters for METOP-B was calculated from the initial calibration parameters ( S1=0.96, S2=1.087 ) provided by Tiejun Chang and Fred Wu on 11/23/2012.
Recent Improvement on VHP system • AVHRR GVI Control file: Added Two control parameters: • (1) option to skip water pixels when making N-days composite, • (2) option to ignore scan error test so that Metop-B data at early stage (before formal operation) can be processed.
Other improvement on VHP UseSatellite ID instead of satellite number when finding the input L1B files by “scdr-files” command Impact: This feature is designed for STAR scientists only. For OSPO, input L1B files should be available in a folder.
Other improvement on VHP Using macro statement to make the source code simple, without impact on program execution. File: lib_basic.h //the following macro statements will check potential errors before execution, when error, print the error location andmessageandexit the program #define ADDSTRINGS(a,b,c) addString(__FUNCTION__,__FILE__,__LINE__,a,b,c) #define CHECK_DIVISOR(d) checkDivisor(__FUNCTION__,__FILE__,__LINE__,d) #define ALLOCATE(size) allocate(size, __FUNCTION__,__FILE__,__LINE__) #define ERROR_OPEN_FILE(file) failOpenFile_exit(__FUNCTION__,__FILE__,__LINE__,file) #define ERROR_EXIT(message,value) error_exit( __FUNCTION__,__FILE__,__LINE__,message,value) #define CHECK_NC_ERROR(e) check_NC_error( __FUNCTION__,__FILE__,__LINE__,e) For example: In the source codes of VHP package, “checkDivisor” will be replaced by “CHECK_DIVISOR” and the program works in the same way. Original statement: checkDivisor (__FUNCTION__,__FILE__,__LINE__, dLat); New statement: CHECK_DIVISOR(dLat); Although we remove the location of calling statement, “__FUNCTION__, __FILE__, __LINE__”, the macro function CHECK_DIVISOR will and automatically added them back so that detail messages on where error occurs will be printed out. Impact: code will be more readable.
Other improvement on VHP Resolution flag in file name: VHP_40S60N.G1200m.C07.M1.P2012046.S316.E322.hdf Impact: If resolution < 4km, it will be presented by meters.