Product definition document:
PDD_SCA_L2-FLUX_V1_R2.pdf (updated in March 2019)Version history:
Version 1.00: Released October 2013. Original versionVersion 2.00: Released January 2015. Minor correction of the albedo calculation. Minor format corrections.
Version 2.01: Released March 2019. 1. Relative Azimuth angle: The β angle, the angle between the direction of the Sun and the orbit plane varies from -45° to 45° for Megha-Tropiques platform. It is necessary to turn the satellite round (flip maneuver) so that the solar panels are more illuminated (see Handbook of Satellite orbits from Michel Capderou).
This flip maneuver is made when the sign of β changes , and the referential for calculating the azimuth angle too. We calculate the new relative azimuth angle to have the same convention of azimuth calculation: the Sun always have a relative azimuth angle of 180°.
2. Auxiliary Channels: The two auxiliary channels radiances (Infrared and visible) are added in the L2B files ( TOA_IR_Rad and TOA_VIS_Rad)
File description: MT1_L2-FLUX-SCASL1A2-1.06_2015-01-01T12-42-24_V2-00.hdf
Data_Fields/SEL_TOA_LW_Flux dataset attributes
| Dataset attribute | DataType | Dimensions | Value |
| units | string | 1 | W m-2 |
| long_name | string | 1 | SEL_TOA_LW_Flux |
| HDF_Calibration_Equation | string | 1 | physical_value = scale_factor*(SDS_count - add_offset) |
| Missing_Output | float32 | 1 | 999999.0 |
| QA_SDS | string | 1 | N/A |
| actual_range | float32 | 2 | [78.429725646972656, 321.48907470703125] |
| Num_Fill | uint32 | 1 | 0 |
| Num_Missing_Output | uint32 | 1 | 3 |
| Num_Valid | uint32 | 1 | 38145 |
| Physical_Range | float64 | 2 | [0.0, 500.0] |
| Comments | string | 1 | The LW unfiltered radiance is converted into flux, using the view angle and colatitude, the scene identification and the LW Erbe anisotropic function (Suttles et al, 1988). A linear interpolation of the anisotropic function between view angle and colatitude is also used. |
| L2-FLUX_failed_value | float32 | 1 | 32767.0 |
| valid_range | float32 | 2 | [0.0, 500.0] |
| _FillValue | float32 | 1 | 99999.0 |
| scale_factor | float64 | 1 | 1.0 |
| scale_factor_err | float64 | 1 | 0.0 |
| add_offset | float64 | 1 | 0.0 |
| add_offset_err | float64 | 1 | 0.0 |
| calibrated_nt | int32 | 1 | 5 |
