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MOD10_L2 and MYD10_L2 Local Snow Cover Attributes, Version 5

Local attributes describe the data and provide summary information about the results of the snow cover algorithm. Two types of local attributes are reported: Hierarchical Data Format (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 Scientific Data Set (SDS). snow covered land
Unit units International System of Units (SI) of the data. This attribute may or may not be used. none
Format format How the data should be viewed in Fortran format notation. Not used in the geolocation fields. I3
Coordinate system coordsys Coordinate system to use for the data. Not used in the geolocation fields. cartesian
Range valid_range Maximum and minimum 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


Custom Local Attributes for the Snow_Cover Field

Attribute Name
Definition
Sample Value
Key Key to the meaining of the coded integers within the SDS.
Value
Description
0 = missing data
L1B data missing
1 = no decision
no decision
11 = night
darkness, terminator, or polar
25 = no snow
snow-free land
37 = lake
lake or inland water
39 = ocean
open water
50 = cloud
cloud obscured
100 = lake ice
snow-covered lake ice
200 = snow
snow-covered land
254 = detector saturated
detector saturated
255 = fill
fill

Attribute Name
Definition
Sample Value
Nadir_data_resolution Nominal spatial resolution of the pixels at nadir.
500 m
Valid EV Obs Band 1 Percentage¹ of valid observations from Level 1B in Band 1 of the swath.
100.0
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 1 Percentage¹ of saturated observations from Level 1B in Band 1 of the swath.
0.342
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

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



Custom Local Attributes for the Snow_Cover_Pixel_QA Field

Attribute Name
Definition
Value
Key Explanation of the Quality Assessment (QA) Flag. 0 = good quality
1 = other quality
252 = Antarctica mask¹
253 = land mask
254 = ocean mask
255 = fill

¹ Antarctica is not masked in the MOD10_L2 product; however, it is masked in the Climate Modeling Grid (CMG) products such as MOD10C1. This is the standard QA key used for all the snow products.



Custom Local Attributes for the Fractional_Snow_Cover Field

Attribute Name
Definition
Sample Value
Key Key to the meaining of the coded integers within the SDS.
Value Description
0 - 100 = fractional snow in percent
200 = missing data L1B data missing
201 = no decision no decision
211 = night darkness, terminator, or polar
225 = land snow-free land
237 = inland water lake or inland water
239 = ocean open water
250 = cloud cloud obscured
254 = detector saturated detector saturated
255 = fill fill
Nadir_data_resolution Data resolution at center of scan (space craft nadir direction). 500 m


Custom Local Attributes for the Latitude Field

Attribute Name
Definition
Sample Value
Source Where the geolocation information came from. MOD03 geolocation product; data read from center pixel in a 5 km box.


Custom Local Attributes for the Longitude Field

Attribute Name
Definition
Sample Value
Source Where the geolocation information came from. MOD03 geolocation product; data read from center pixel in a 5 km box.