9 MOD13C2 CMG (monthly 0.05-deg) VI

Global MOD13C2 data are cloud-free spatial composites of the gridded monthly 1-km MOD13A3 product. MOD13C3 is provided as a level-3 product projected on a 0.05 degree (5600-meter) geographic (lat/lon) Climate Modeling Grid (CMG). Cloud-free global coverage is achieved by replacing clouds with the historical MODIS time series climatology record.

MOD13C2 product is analogous to MOD13C1 but based on MOD13A3 for a monthly temporal resolution; all other specs are kept the same, and production features retained. See Section 8 for more details.

9.1 Algorithm Description

Algorithm is as for MOD13C1, but using monthly MOD13A3 as input.

9.2 Scientific Data Sets

MOD13C2 VI product has 13 SDSs, as listed in Table 19.

Table 19: List of SDS’s from monthly 0.05-deg MOD13C2 VI.

Science Data Set

Units

Data type

Valid Range

Scale factor

CMG 0.05 Deg Monthly NDVI

NDVI

int16

-2000, 10000

0.0001

CMG 0.05 Deg Monthly EVI

EVI

int16

-2000, 10000

0.0001

CMG 0.05 Deg Monthly VI Quality

Bits

uint16

0, 65534

NA

CMG 0.05 Deg Monthly red reflectance (Band 1)

Reflectance

int16

0, 10000

0.0001

CMG 0.05 Deg Monthly NIR reflectance (Band 2)

Reflectance

int16

0, 10000

0.0001

CMG 0.05 Deg Monthly blue reflectance (Band 3)

Reflectance

int16

0, 10000

0.0001

CMG 0.05 Deg Monthly MIR reflectance (Band 7)

Reflectance

int16

0, 10000

0.0001

CMG 0.05 Deg Monthly Avg sun zenith angle

Degree

int16

-9000, 9000

0.01

CMG 0.05 Deg Monthly NDVI std dev

NDVI

int16

-2000, 10000

0.0001

CMG 0.05 Deg Monthly EVI std dev

EVI

int16

-2000, 10000

0.0001

CMG 0.05 Deg Monthly #1km pix used

Pixels

uint8

0, 36

1

CMG 0.05 Deg Monthly #1km pix +-30deg VZ

Pixels

uint8

0, 36

1

CMG 0.05 Deg Monthly pixel reliability

Rank

int8

0, 4

1


9.3 Quality Assurance

As in MOD13C1, QA metadata objects summarize tile-level quality with several single words and numeric numbers, and thus are useful for data ordering and screening processes.

QA SDSs document product quality on a pixel-by-pixel basis and thus are useful for data analyses and application uses of the data. Each MOD13C3 output pixel has a ranked summary quality SDS (Table 4), and a single QA SDS for both NDVI and EVI quality assurance (Table 5).

QA Metadata

A listing of the metadata fields used for QA evaluations of the MOD13C2 VI product is included in Table 16.

QA Science Data Sets

QA SDS for MOD13C3 are the same as for MOD13C1 (See Section for details).