MOD29 and MYD29 Local Attributes

Local attributes describe the data and provide summary data on the results of the sea ice algorithm. Two types of local attributes are reported: HDF predefined, and custom local attributes.

HDF Predefined Local Attributes

Attribute Name Reserved Label(s) Definition Sample Value
Label long_name Long name of the SDS Sea ice by reflective characteristics
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 cartesian
Range valid_range Max and min values within a selected data range 0,254
Fill Value _FillValue Data used to fill gaps in the swath 65535 (IST)
Calibration scale_factor
scale_factor_err
add_offset
add_offset_err
calibrated_nt		 Used if data are stored in calibrated form (IST only)



Custom Local Attributes

Sea Ice by Reflectance
Attribute Name Definition Sample Value
Key Key to meaning of data See pixel values.
Nadir_data_resolution Nominal spatial resolution of the pixels at nadir 1 km
Valid EV Obs Band 2 Percentage¹ of valid observations from Level 1B in Band 2 of the swath 100.0
Valid EV Obs Band 4 Percentage¹ of valid observations from Level 1B in Band 4 of the swath 100.0
Valid EV Obs Band 6 Percentage¹ of valid observations from Level 1B in Band 6 of the swath 100.0
Saturated EV Obs Band 2 Percentage¹ of saturated observations from Level 1B in Band 2 of the swath 0.287
Saturated EV Obs Band 4 Percentage¹ of saturated observations from Level 1B in Band 4 of the swath 0.779
Saturated EV Obs Band 6 Percentage¹ of saturated observations from Level 1B in Band 6 of the swath 0.698


Sea Ice by Reflectance PixelQA
Attribute Name Definition
Key: See MODIS Sea Ice Quality Assurance Fields for definition of bit values


Ice Surface Temperature
Attribute Name Definition Sample Value
Key: Key to meaning of data See pixel values.
Valid EV Obs Band 31 Percentage of valid observations from level 1B in band 31 in the swath 100.0
Valid EV Obs Band 32 Percentage of valid observations from level 1B in band 32 in the swath 100.0
Saturated EV Obs Band 31 Percentage of saturated observations from level 1B in band 31 in the swath 0.287
Saturated EV Obs Band 32 Percentage of saturated observations from level 1B in band 32 in the swath 0.779
Auto_Check_QA For internal QA checks "Acceptable"
IST coefficients, <240 Coefficients used in the IST calculation for the given temperature range -0.15, 0.99, 1.39, -0.41
IST coefficients, 240-260 -3.32, 1.01, 1.21, 0.13
IST coefficients, >260 -5.02, 1.01, 1.51, 0.26


Ice Surface Temperature PixelQA
Attribute Name Definition
Key: See MODIS Sea Ice Quality Assurance Fields for definition of bit values


Sea Ice by IST
Attribute Name Definition Sample Value
Key: Key to meaning of data See pixel values.


Combined Sea Ice
Attribute Name Definition Sample Value
Key: Key to meaning of data See pixel values.

¹ These percentages are based on the total number of pixels in the swath (x dimensions * y dimensions).