|
||||||
|
|
||||||
Local attributes describe the data and provide summary data on the results of the snow cover algorithm. Two types of local attributes are reported: HDF predefined, and custom local attributes.
| Attribute Name | Reserved Label(s) | Definition | Sample Value |
| Label | long_name | Long name of the SDS | Snow_covered_land |
| Unit | units | SI units of the data, if any | none |
| Format | format | How the data should be viewed in Fortran format notation | I3 |
| Coordinate system | coordsys | Coordinate system to use for the data | latitude, longitude |
| Range | valid_range | Max and min values within a selected data range | 0-254 |
| Fill Value | Fill_Value | Data used to fill gaps in the swath | 255 |
| Calibration | scale_factor scale_factor_err add_offset add_offset_err calibrated_nt |
Not used | Not used |
| Attribute Name | Definition | Sample Value |
| Key | Key to meaning of data in the SDS |
|
| Valid EV Obs Band 1 | Percentage² of valid observations from Level 1B in Band 1 of the swath | 100.0 |
| Valid EV Obs Band 2 | Percentage² of valid observations from Level 1B in Band 2 of the swath | 100.0 |
| Valid EV Obs Band 4 | Percentage² of valid observations from Level 1B in Band 4 of the swath | 100.0 |
| Valid EV Obs Band 6 | Percentage² of valid observations from Level 1B in Band 6 of the swath | 100.0 |
| Saturated EV Obs Band 1 | Percentage² of saturated observations from Level 1B in Band 1 of the swath | 0.342 |
| Saturated EV Obs Band 2 | Percentage² of saturated observations from Level 1B in Band 2 of the swath | 0.287 |
| Saturated EV Obs Band 4 | Percentage² of saturated observations from Level 1B in Band 4 of the swath | 0.779 |
| Saturated EV Obs Band 6 | Percentage² of saturated observations from Level 1B in Band 6 of the swath | 0.698 |
| Auto_check_QA | If all the data and intermediate calculations did not exceed a 15% limit of anomalous conditions, the snow cover algorithm result is considered acceptable; otherwise, it is questionable | "Acceptable" |
| Attribute Name | Definition | Sample Value |
| Key | Explanation of the QA flag | Bits 0 and 1: 00 = nominal 01 = abnormal 10 = cloud-obscured 11 = invalid Bit 2: 0 = nominal 1 = averaged or replaced Bit 3: 0 = within 45° scan angle 1 = beyond 45° scan angle Bit 4: 0 = nominal 1 = high band 6 uncertainty index Bit 5: 0 = cloud mask used 1 = cloud mask not used Bit 6: 0 = nominal 1 = noisy level 1b data Bit 7: 0 = nominal 1 = unusable level 1b data |
| Invalid_input | Percentage of invalid L1B input data | 1 |
| Nominal_results | Percentage of pixels for which algorithm execution was nominal | 95 |
| Abnormal_results | Percentage of pixels for which algorithm execution encountered conditions outside of nominal range |
2 |
| Cloud_obscured | Percentage of pixels that were identified as cloud | 2 |
¹ These percentages are based on the number of land pixels in the swath. Only land pixels are analyzed for snow cover.
² These percentages are based on the total number of pixels in the swath (x dimensions * y dimensions).
³ These percentages are based on the number of inland water pixels in the swath.
