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_SW_Flux dataset attributes
| Dataset attribute | DataType | Dimensions | Value |
| units | string | 1 | W m-2 |
| long_name | string | 1 | SEL_TOA_SW_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 | [0.0, 32767.0] |
| Num_Fill | uint32 | 1 | 0 |
| Num_Missing_Output | uint32 | 1 | 3 |
| Num_Valid | uint32 | 1 | 38145 |
| Physical_Range | float64 | 2 | [0.0, 1000.0] |
| Comments | string | 1 | The SW unfiltered radiance is converted into flux, using the view and sun angles, the scene identification and the SW Erbe bi-directional function (Suttles et al, 1988). A linear interpolation of BRDF between angles is used in order to remove the discrete nature of the angular model TOA : top of atmosphere (30km altitude as in Erbe). |
| L2-FLUX_failed_value | float32 | 1 | 32767.0 |
| valid_range | float32 | 2 | [0.0, 1000.0] |
| _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 |
