USDA, National Agricultural Statistics Service, 2008 California Cropland Data Layer

Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator:
United States Department of Agriculture (USDA), National Agricultural Statistics Service (NASS), Research and Development Division (RDD), Geospatial Information Branch (GIB), Spatial Analysis Research Section (SARS)
Publication_Date: 20120131
Title:
USDA, National Agricultural Statistics Service, 2008 California Cropland Data Layer
Edition: 2008 Edition
Geospatial_Data_Presentation_Form: raster digital data
Publication_Information:
Publication_Place:
USDA, NASS Marketing and Information Services Office, Washington, D.C.
Publisher: USDA, NASS
Other_Citation_Details:
NASS maintains a Frequently Asked Questions (FAQ's) section on the CDL website at <http://www.nass.usda.gov/research/Cropland/SARS1a.htm>. The data is available free for download through CropScape at <http://nassgeodata.gmu.edu/CropScape/>. The data is also available free for download through the Geospatial Data Gateway at <http://datagateway.nrcs.usda.gov/>. See the 'Ordering Instructions' section of this metadata file for detailed Geospatial Data Gateway download instructions.
Online_Linkage: <http://nassgeodata.gmu.edu/CropScape/CA>
Description:
Abstract:
The USDA, NASS Cropland Data Layer (CDL) is a raster, geo-referenced, crop-specific land cover data layer. The 2008 CDL has a ground resolution of 30 meters. The CDL is produced using satellite imagery from the Landsat 5 TM sensor, Landsat 7 ETM+ sensor, and the Indian Remote Sensing RESOURCESAT-1 (IRS-P6) Advanced Wide Field Sensor (AWiFS) collected during the current growing season.
Some CDL states used additional satellite imagery and ancillary inputs to supplement and improve the classification. These additional sources can include the United States Geological Survey (USGS) National Elevation Dataset (NED), the imperviousness and canopy data layers from the USGS National Land Cover Database 2006 (NLCD 2006), and the National Aeronautics and Space Administration (NASA) Moderate Resolution Imaging Spectroradiometer (MODIS) 250 meter 16 day Normalized Difference Vegetation Index (NDVI) composites.
Agricultural training and validation data are derived from the Farm Service Agency (FSA) Common Land Unit (CLU) Program. The NLCD 2006 is used as non-agricultural training and validation data.
Please refer to the 'Supplemental_Information' Section of this metadata file for a complete list of all imagery, ancillary data, and training/validation data used to generate this state's CDL.
The strength and emphasis of the CDL is agricultural land cover. Please note that no farmer reported data are derivable from the Cropland Data Layer.
Purpose:
The purpose of the Cropland Data Layer Program is to use satellite imagery to (1) provide acreage estimates to the Agricultural Statistics Board for the state's major commodities and (2) produce digital, crop-specific, categorized geo-referenced output products.
Supplemental_Information:
If the following table does not display properly, then please visit the following website to view the original metadata file <http://www.nass.usda.gov/research/Cropland/metadata/meta.htm>. 
USDA, National Agricultural Statistics Service 2008 California Cropland Data Layer

CLASSIFICATION INPUTS:
AWIFS DATE 20081010 PATH 252 ROW(S)&QUADRANT(S) 45D
AWIFS DATE 20081019 PATH 249 ROW(S)&QUADRANT(S) 45BD
AWIFS DATE 20081028 PATH 246 ROW(S)&QUADRANT(S) 45B

LANDSAT 5 TM DATE 20080411 PATH 043 ROW(S) 32-35
LANDSAT 5 TM DATE 20080413 PATH 041 ROW(S) 26-28 34-37
LANDSAT 5 TM DATE 20080418 PATH 044 ROW(S) 31-34
LANDSAT 5 TM DATE 20080420 PATH 042 ROW(S) 33-36
LANDSAT 5 TM DATE 20080422 PATH 040 ROW(S) 35-37
LANDSAT 5 TM DATE 20080424 PATH 038 ROW(S) 36-37
LANDSAT 5 TM DATE 20080425 PATH 045 ROW(S) 26-28 31-33
LANDSAT 5 TM DATE 20080501 PATH 039 ROW(S) 35-37
LANDSAT 5 TM DATE 20080511 PATH 045 ROW(S) 32-33
LANDSAT 5 TM DATE 20080513 PATH 043 ROW(S) 32-35
LANDSAT 5 TM DATE 20080518 PATH 046 ROW(S) 26-32
LANDSAT 5 TM DATE 20080529 PATH 043 ROW(S) 34
LANDSAT 5 TM DATE 20080531 PATH 041 ROW(S) 34-36
LANDSAT 5 TM DATE 20080605 PATH 044 ROW(S) 32-34
LANDSAT 5 TM DATE 20080611 PATH 038 ROW(S) 36-37
LANDSAT 5 TM DATE 20080618 PATH 039 ROW(S) 26-31 35-37
LANDSAT 5 TM DATE 20080619 PATH 046 ROW(S) 28-32
LANDSAT 5 TM DATE 20080623 PATH 042 ROW(S) 27-31 33-36
LANDSAT 5 TM DATE 20080625 PATH 040 ROW(S) 26-28 35-37
LANDSAT 5 TM DATE 20080628 PATH 045 ROW(S) 26-33
LANDSAT 5 TM DATE 20080630 PATH 043 ROW(S) 27-28 32-35
LANDSAT 5 TM DATE 20080702 PATH 041 ROW(S) 28-31 34-36
LANDSAT 5 TM DATE 20080707 PATH 044 ROW(S) 26-34
LANDSAT 5 TM DATE 20080718 PATH 041 ROW(S) 27-28 30-31 34-36
LANDSAT 5 TM DATE 20080723 PATH 044 ROW(S) 27-34
LANDSAT 5 TM DATE 20080725 PATH 042 ROW(S) 26-31 33-36
LANDSAT 5 TM DATE 20080729 PATH 038 ROW(S) 26-31 36-37
LANDSAT 5 TM DATE 20080730 PATH 045 ROW(S) 29-33
LANDSAT 5 TM DATE 20080801 PATH 043 ROW(S) 29-35
LANDSAT 5 TM DATE 20080803 PATH 041 ROW(S) 29-31 34-36
LANDSAT 5 TM DATE 20080810 PATH 042 ROW(S) 30-31 33-36
LANDSAT 5 TM DATE 20080812 PATH 040 ROW(S) 26-31 35-37
LANDSAT 5 TM DATE 20080821 PATH 039 ROW(S) 35-37
LANDSAT 5 TM DATE 20080824 PATH 044 ROW(S) 29-34
LANDSAT 5 TM DATE 20080831 PATH 045 ROW(S) 30-33
LANDSAT 5 TM DATE 20080902 PATH 043 ROW(S) 26-28 32-35
LANDSAT 5 TM DATE 20080904 PATH 041 ROW(S) 30-31 34-36
LANDSAT 5 TM DATE 20080906 PATH 039 ROW(S) 30-31 35-37
LANDSAT 5 TM DATE 20080907 PATH 046 ROW(S) 26-32
LANDSAT 5 TM DATE 20080911 PATH 042 ROW(S) 26-31 33-36
LANDSAT 5 TM DATE 20080913 PATH 040 ROW(S) 29-31 35-37
LANDSAT 5 TM DATE 20080915 PATH 038 ROW(S) 26-31 36-37

USGS, NATIONAL ELEVATION DATASET
USGS, NATIONAL LAND COVER DATABASE 2006 IMPERVIOUSNESS
USGS, NATIONAL LAND COVER DATABASE 2001 TREE CANOPY
USFS, NATIONAL FOREST TYPE DATASET
USFS, NATIONAL FOREST BIOMASS DATASET

TRAINING AND VALIDATION:
USDA, FARM SERVICE AGENCY 2008 COMMON LAND UNIT DATA
USGS, NATIONAL LAND COVER DATABASE 2006
US BUREAU OF RECLAMATION, LOWER COLORADO RIVER ACCOUNTING SYSTEM 2008 CROP CLASSIFICATIONS

NOTE: The final extent of the CDL is clipped to the state boundary
even though the raw input data may encompass a larger area.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20070925
Ending_Date: 20081230
Currentness_Reference: 2008 growing season
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -124.5876
East_Bounding_Coordinate: -114.1885
North_Bounding_Coordinate: 41.9743
South_Bounding_Coordinate: 32.5028
Keywords:
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: farming, 001
Theme_Keyword: environment, 007
Theme_Keyword: imageryBaseMapsEarthCover, 010
Theme:
Theme_Keyword_Thesaurus: Global Change Master Directory (GCMD) Science Keywords
Theme_Keyword:
Earth Science > Biosphere > Terrestrial Ecosystems > Agricultural Lands
Theme_Keyword: Earth Science > Land Surface > Land Use/Land Cover > Land Cover

Theme:
Theme_Keyword_Thesaurus: Global Change Master Directory (GCMD) Instrument Keywords
Theme_Keyword: MODIS > Moderate-Resolution Imaging Spectroradiometer

Theme:
Theme_Keyword_Thesaurus: None

Theme_Keyword: crop cover
Theme_Keyword: cropland
Theme_Keyword: agriculture
Theme_Keyword: farming
Theme_Keyword: land cover
Theme_Keyword: crop estimates
Theme_Keyword: AWiFS
Theme_Keyword: MODIS
Theme_Keyword: Landsat
Theme_Keyword: CropScape
Place:
Place_Keyword_Thesaurus: Global Change Master Directory (GCMD) Location Keywords
Place_Keyword:
Continent > North America > United States of America > California
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: California
Place_Keyword: CA

Temporal:
Temporal_Keyword_Thesaurus: None
Temporal_Keyword: 2008
Access_Constraints: None
Use_Constraints:
The USDA, NASS Cropland Data Layer is provided to the public as is and is considered public domain and free to redistribute. The USDA, NASS does not warrant any conclusions drawn from these data. If the user does not have software capable of viewing GEOTIF (.tif) file formats then we suggest using the Cropscape website <http://nassgeodata.gmu.edu/CropScape/> or the freeware browser ESRI ArcGIS Explorer <http://www.esri.com/>.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: USDA, NASS, Spatial Analysis Research Section
Contact_Person: USDA, NASS, Spatial Analysis Research Section staff
Contact_Address:
Address_Type: mailing and physical address
Address: 3251 Old Lee Highway, Room 305
City: Fairfax
State_or_Province: Virginia
Postal_Code: 22030-1504
Country: USA
Contact_Voice_Telephone: 703-877-8000
Contact_Facsimile_Telephone: 703-877-8044
Contact_Electronic_Mail_Address: HQ_RDD_GIB@nass.usda.gov
Data_Set_Credit: USDA, National Agricultural Statistics Service
Security_Information:
Security_Classification_System: None
Security_Classification: Unclassified
Security_Handling_Description: None
Native_Data_Set_Environment:
Microsoft Windows XP; ERDAS Imagine Versions 9.1, 9.2 and 9.3 <http://www.erdas.com/>; ESRI ArcGIS Version 9.3 <http://www.esri.com/>; Rulequest See5.0 Release 2.07 <http://www.rulequest.com/>; NLCD Mapping Tool <http://www.mrlc.gov/>.
ERDAS Imagine is used in the pre- and post- processing of all raster-based data. ESRI ArcGIS is used to prepare the vector-based Farm Service Agency (FSA) Common Land Unit (CLU) training and validation data. Rulequest See5.0 is used to create a decision-tree based classifier. The NLCD Mapping Tool is used to apply the See5.0 decision-tree via ERDAS Imagine. This is a departure from older versions of the CDL that were created using in-house software (Peditor) based upon a maximum likelihood classifier approach. Check this section and the 'Process Description' section of the specific state and year metadata file to verify what methodology was used.
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
If the following table does not display properly, then please visit this internet site <http://www.nass.usda.gov/research/Cropland/metadata/meta.htm> to view the original metadata file. 

USDA, National Agricultural Statistics Service, 2008 California Cropland Data Layer
STATEWIDE AGRICULTURAL ACCURACY REPORT

Crop-specific covers only  *Correct  Accuracy   Error   Kappa
-------------------------   -------  --------  ------   -----
OVERALL ACCURACY**        1,639,245     85.1%   14.9%   0.833


Cover                          Attribute  *Correct  Producer's  Omission            User's  Commission  Cond'l
Type                                Code    Pixels   Accuracy     Error   Kappa   Accuracy      Error    Kappa
----                                ----    ------   --------     -----   -----   --------      -----    -----
Corn                                   1     92569     90.22%     9.78%   0.897     88.58%     11.42%    0.880
Cotton                                 2    128466     97.80%     2.20%   0.976     97.22%      2.78%    0.970
Rice                                   3    345018     98.91%     1.09%   0.987     99.04%      0.96%    0.989
Sorghum                                4       292     20.17%    79.83%   0.201     40.90%     59.10%    0.409
Sunflower                              6       380     23.23%    76.77%   0.232     50.00%     50.00%    0.500
Pop. or Orn. Corn                     13         3      0.82%    99.18%   0.008     75.00%     25.00%    0.750
Mint                                  14      1413     68.36%    31.64%   0.683     90.23%      9.77%    0.902
Barley                                21     23117     63.77%    36.23%   0.633     77.74%     22.26%    0.774
Durum Wheat                           22     29944     67.56%    32.44%   0.670     88.76%     11.24%    0.885
Spring Wheat                          23      6918     77.45%    22.55%   0.774     79.70%     20.30%    0.796
Winter Wheat                          24    163904     84.31%    15.69%   0.827     80.76%     19.24%    0.788
Other Small Grains                    25      5627     99.31%     0.69%   0.993     86.17%     13.83%    0.861
Rye                                   27      4253     61.20%    38.80%   0.611     70.75%     29.25%    0.707
Oats                                  28     21007     52.20%    47.80%   0.514     62.58%     37.42%    0.619
Safflower                             33     25476     83.67%    16.33%   0.834     86.04%     13.96%    0.858
Alfalfa                               36    355218     94.03%     5.97%   0.927     93.00%      7.00%    0.915
Sugarbeets                            41      1502     95.18%     4.82%   0.952     96.97%      3.03%    0.970
Dry Beans                             42       913     65.17%    34.83%   0.651     70.23%     29.77%    0.702
Potatoes                              43      2512     71.87%    28.13%   0.718     90.20%      9.80%    0.902
Other Crops                           44     10722     83.57%    16.43%   0.835     92.35%      7.65%    0.923
Sweet Potatoes                        46      1134     82.89%    17.11%   0.829     78.70%     21.30%    0.787
Misc. Vegs. & Fruits                  47       418     20.03%    79.97%   0.200     88.00%     12.00%    0.880
Watermelons                           48       432     75.00%    25.00%   0.750     94.12%      5.88%    0.941
Onions                                49       485     50.73%    49.27%   0.507     98.78%      1.22%    0.988
Peas                                  53         0      0.00%   100.00%   0.000      0.00%    100.00%    0.000
Tomatoes                              54      8209     66.24%    33.76%   0.661     78.11%     21.89%    0.780
Herbs                                 57       381     66.03%    33.97%   0.660     89.02%     10.98%    0.890
Clover/Wildflowers                    58     11859     74.63%    25.37%   0.745     88.63%     11.37%    0.885
Sod/Grass Seed                        59      1236     40.93%    59.07%   0.409     77.83%     22.17%    0.778
Fallow/Idle Cropland                  61    155772     74.79%    25.21%   0.724     83.35%     16.65%    0.815
Cherries                              66      1086     46.15%    53.85%   0.461     53.90%     46.10%    0.538
Peaches                               67       540     27.48%    72.52%   0.274     48.65%     51.35%    0.486
Apples                                68       135     30.54%    69.46%   0.305     65.85%     34.15%    0.658
Grapes                                69     21175     79.72%    20.28%   0.795     81.69%     18.31%    0.815
Other Tree Crops                      71      7172     98.25%     1.75%   0.982     95.75%      4.25%    0.957
Citrus                                72        39     14.34%    85.66%   0.143     42.86%     57.14%    0.428
Pecans                                74         0      0.00%   100.00%   0.000      0.00%    100.00%    0.000
Almonds                               75     92713     85.12%    14.88%   0.843     86.43%     13.57%    0.857
Walnuts                               76     26268     71.65%    28.35%   0.712     73.37%     26.63%    0.729
Aquaculture                           92       266     84.98%    15.02%   0.850     94.66%      5.34%    0.947
Pistachios                           204     13442     70.69%    29.31%   0.705     83.39%     16.61%    0.832
Triticale                            205       790     23.80%    76.20%   0.237     62.65%     37.35%    0.626
Carrots                              206       111     95.69%     4.31%   0.957    100.00%      0.00%    1.000
Asparagus                            207       628     45.67%    54.33%   0.457     93.04%      6.96%    0.930
Garlic                               208       296     68.20%    31.80%   0.682     98.01%      1.99%    0.980
Cantaloupes                          209      1314     38.40%    61.60%   0.383     60.28%     39.72%    0.602
Prunes                               210      6695     53.75%    46.25%   0.535     61.50%     38.50%    0.613
Olives                               211      5139     66.52%    33.48%   0.664     75.31%     24.69%    0.752
Oranges                              212     15364     95.80%     4.20%   0.958     94.21%      5.79%    0.942
Honeydew Melons                      213        35     97.22%     2.78%   0.972    100.00%      0.00%    1.000
Peppers                              216       115     49.78%    50.22%   0.498     61.83%     38.17%    0.618
Pomegranates                         217      1169     71.85%    28.15%   0.718     76.96%     23.04%    0.769
Nectarines                           218        99     15.11%    84.89%   0.151     28.95%     71.05%    0.289
Greens                               219       386     35.00%    65.00%   0.350     95.54%      4.46%    0.955
Plums                                220       103     20.44%    79.56%   0.204     26.14%     73.86%    0.261
Strawberries                         221       689     45.51%    54.49%   0.455     90.90%      9.10%    0.909
Squash                               222        63     98.44%     1.56%   0.984    100.00%      0.00%    1.000
Apricots                             223       235     38.71%    61.29%   0.387     81.88%     18.12%    0.819
Vetch                                224        34     13.65%    86.35%   0.136     23.94%     76.06%    0.239
Dbl. Crop WinWht/Corn                225     13319     56.92%    43.08%   0.565     64.12%     35.88%    0.637
Dbl. Crop Oats/Corn                  226     27785     77.92%    22.08%   0.775     73.35%     26.65%    0.729
Lettuce                              227       810     33.28%    66.72%   0.332     80.20%     19.80%    0.802
Pumpkins                             229        27     26.73%    73.27%   0.267     90.00%     10.00%    0.900
Dbl. Crop Lettuce/Durum Wht          230        32     11.94%    88.06%   0.119     15.69%     84.31%    0.157
Dbl. Crop Lettuce/Cantaloupe         231         0      0.00%   100.00%   0.000       n/a        n/a      n/a
Dbl. Crop Lettuce/Upland Cotton      232         0      0.00%   100.00%   0.000       n/a        n/a      n/a
Dbl. Crop Durum Wht/Sorghum          234      1428     46.05%    53.95%   0.460     90.04%      9.96%    0.900
Dbl. Crop WinWht/Sorghum             236       161     37.27%    62.73%   0.373     32.86%     67.14%    0.328
Blueberries                          242         0      0.00%   100.00%   0.000      0.00%    100.00%    0.000
Radishes                             246         9     24.32%    75.68%   0.243     50.00%     50.00%    0.500
Cranberries                          250         0      0.00%   100.00%   0.000       n/a        n/a      n/a

*Correct Pixels represents the total number of independent validation pixels correctly identified in the error matrix.
**The Overall Accuracy represents only the FSA row crops and annual fruit and vegetables (codes 1-61,66-80 and 200-255).
FSA-sampled grass and pasture, aquaculture, and all NLCD-sampled categories (codes 62-65 and 81-199) are not included in
the Overall Accuracy.
The accuracy of the non-agricultural land cover classes within the Cropland Data Layer is entirely dependent upon the USGS, National Land Cover Database (NLCD 2006). Thus, the USDA, NASS recommends that users consider the NLCD for studies involving non-agricultural land cover. For more information on the accuracy of the NLCD please reference <http://www.mrlc.gov/>.
Quantitative_Attribute_Accuracy_Assessment:
Attribute_Accuracy_Value:
Classification accuracy is generally 85% to 95% correct for the major crop-specific land cover categories. See the 'Attribute Accuracy Report' section of this metadata file for the detailed accuracy report.
Attribute_Accuracy_Explanation:
The strength and emphasis of the CDL is crop-specific land cover categories. The accuracy of the CDL non-agricultural land cover classes is entirely dependent upon the USGS, National Land Cover Database (NLCD 2006). Thus, the USDA, NASS recommends that users consider the NLCD for studies involving non-agricultural land cover.

These definitions of accuracy statistics were derived from the following book: Congalton, Russell G. and Kass Green. Assessing the Accuracy of Remotely Sensed Data: Principles and Practices. Boca Raton, Florida: CRC Press, Inc. 1999. The 'Producer's Accuracy' is calculated for each cover type in the ground truth and indicates the probability that a ground truth pixel will be correctly mapped (across all cover types) and measures 'errors of omission'. An 'Omission Error' occurs when a pixel is excluded from the category to which it belongs in the validation dataset. The 'User's Accuracy' indicates the probability that a pixel from the CDL classification actually matches the ground truth data and measures 'errors of commission'. The 'Commission Error' represent when a pixel is included in an incorrect category according to the validation data. It is important to take into consideration errors of omission and commission. For example, if you classify every pixel in a scene to 'wheat', then you have 100% Producer's Accuracy for the wheat category and 0% Omission Error. However, you would also have a very high error of commission as all other crop types would be included in the incorrect category. The 'Kappa' is a measure of agreement based on the difference between the actual agreement in the error matrix (i.e., the agreement between the remotely sensed classification and the reference data as indicated by the major diagonal) and the chance agreement which is indicated by the row and column totals. The 'Conditional Kappa Coefficient' is the agreement for an individual category within the entire error matrix.
Logical_Consistency_Report:
The Cropland Data Layer (CDL) has been produced using training and independent validation data from the Farm Service Agency (FSA) Common Land Unit (CLU) Program (agricultural data) and United States Geological Survey (USGS) National Land Cover Database 2006 (NLCD 2006). More information about the FSA CLU Program can be found at <http://www.fsa.usda.gov/>. More information about the NLCD 2006 can be found at <http://www.mrlc.gov/>. The CDL encompasses the entire state unless noted otherwise in the 'Completeness Report' section of this metadata file.
Completeness_Report: The entire state is covered by the Cropland Data Layer.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
The Cropland Data Layer retains the spatial attributes of the input imagery. The Landsat 5 TM and Landsat 7 ETM imagery was obtained via download from the USGS Global Visualization Viewer (Glovis) website <http://glovis.usgs.gov/>. Please reference the metadata on the Glovis website for each Landsat scene for positional accuracy. The majority of the Landsat data is available at Level 1T (precision and terrain corrected). The AWiFS imagery used in the production of the Cropland Data Layer is purchased with an orthorectified level of processing. Thus, the CDL will retain the input imagery's positional accuracy of 60 meters at the circular error at the 90 percent confidence level (CE90). CE90 is a standard metric often used for horizontal accuracy in map products and can be interpreted as 90% of well-defined points tested must fall within a certain radial distance.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator:
Indian Remote-Sensing Satellite series of ISRO (Indian Space Research Organization)
Title: RESOURCESAT-1 (IRS-P6) Advanced Wide Field Sensor (AWiFS)
Geospatial_Data_Presentation_Form: remote-sensing image
Publication_Information:
Publisher: EOTec (Earth Observation Technologies, LLC)
Publication_Place: Washington, D.C. 20008
Publication_Date: 2008 growing season
Other_Citation_Details:
The RESOURCESAT-1 (IRS-P6) AWiFS satellite sensor operates in four spectral bands at a spatial resolution of 56 meters. Additional information about AWiFS data can be obtained at <http://www.isro.org/>. The AWiFS imagery used in the Cropland Data Layer is obtained through a partnership with the USDA, Foreign Agricultural Service, International Production Assessment (IPA) Program. Refer to the 'Supplemental Information' Section of this metadata file for specific scene date, path, row and quadrants used as classification inputs.
For the 2008 CDL Program, the AWiFS imagery was resampled to 30 meters to match the Landsat spatial resolution. The resample used bilinear interpolation, polynomial approximation, polynomial order of 3.
Source_Scale_Denominator: 56 meter
Type_of_Source_Media: CD-ROM and/or DVD
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20070925
Ending_Date: 20081230
Source_Currentness_Reference: ground condition
Source_Contribution: Raw data used in land cover spectral signature analysis
Source_Information:
Source_Citation:
Citation_Information:
Originator:
United States Geological Survey (USGS), Earth Resources Observation and Science (EROS)
Title:
Landsat 5 Thematic Mapper (TM) and Landsat 7 Enhanced Thematic Mapper Plus (ETM+)
Geospatial_Data_Presentation_Form: remote-sensing image
Publication_Information:
Publisher: USGS, EROS
Publication_Place: Sioux Falls, South Dakota 57198-001
Publication_Date: 2008 growing season
Other_Citation_Details:
The Landsat 5 TM and Landsat 7 ETM+ data is free for download through the following website <http://glovis.usgs.gov/>. Additional information about Landsat data can be obtained at <http://eros.usgs.gov/>. Refer to the 'Supplemental Information' Section of this metadata file for specific scene date, path and rows used as classification inputs.
Source_Scale_Denominator: 30 meter
Type_of_Source_Media: online download
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20071001
Ending_Date: 20081230
Source_Currentness_Reference: ground condition
Source_Contribution: Raw data used in land cover spectral signature analysis
Source_Information:
Source_Citation:
Citation_Information:
Originator:
United States Geological Survey (USGS) and National Aeronautics and Space Administration (NASA) Land Processes Distributed Active Archive Center (LP DAAC)
Title:
Moderate Resolution Imaging Spectroradiometer (MODIS), 250 meter resolution 16-day composite Normalized Difference Vegetation Index (NDVI) from the Terra satellite (MOD13Q1v4)
Geospatial_Data_Presentation_Form: vegetation indices based on remote-sensing imagery
Publication_Information:
Publisher: USGS Center for Earth Resources Observation and Sciences (EROS)
Publication_Place: Sioux Falls, South Dakota 57198 USA
Publication_Date: late 2007 growing season and the entire 2008 growing season
Other_Citation_Details:
The Moderate Resolution Imaging Spectroradiometer (MODIS), 250 meter resolution 16-day composite Normalized Difference Vegetation Index (NDVI) data products from the Terra satellite (MOD13Q1v4) are downloaded from <https://lpdaac.usgs.gov/>. Often late-season MODIS NDVI data are used from the previous growing season in an effort to improve winter wheat detection. Refer to the 'Supplemental Information' Section of this metadata file for specific dates used as classification inputs.
Source_Scale_Denominator: 250 meter
Type_of_Source_Media: online download
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20071001
Ending_Date: 20080930
Source_Currentness_Reference: ground condition
Source_Contribution: NDVI data used in land cover spectral signature analysis
Source_Information:
Source_Citation:
Citation_Information:
Originator:
United States Geological Survey (USGS) Earth Resources Observation and Science (EROS) Data Center
Title: The National Elevation Dataset (NED)
Geospatial_Data_Presentation_Form: remote-sensing image
Publication_Information:
Publisher: USGS, EROS Data Center
Publication_Place: Sioux Falls, South Dakota 57198 USA
Publication_Date: Continuously updated
Other_Citation_Details:
The USGS NED Digital Elevation Model (DEM) is used as an ancillary data source in the production of the Cropland Data Layer. Slope and Aspect derived from the DEM are also used as additional classification inputs. More information on the USGS NED can be found at <http://ned.usgs.gov/>. Refer to the 'Supplemental Information' Section of this metadata file for the complete list of ancillary data sources used as classification inputs.
Source_Scale_Denominator: 30 meter
Type_of_Source_Media: online
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: unknown
Source_Currentness_Reference: ground condition
Source_Contribution:
spatial and attribute information used in land cover spectral signature analysis
Source_Information:
Source_Citation:
Citation_Information:
Originator:
United States Geological Survey (USGS) Earth Resources Observation and Science (EROS) Data Center
Title: National Land Cover Database 2006 (NLCD 2006)
Geospatial_Data_Presentation_Form: remote-sensing image
Publication_Information:
Publisher: USGS, EROS Data Center
Publication_Place: Sioux Falls, South Dakota 57198 USA
Publication_Date: 2006
Other_Citation_Details:
The NLCD 2006 was used as ground training and validation for non-agricultural categories. Additionally, the USGS NLCD 2006 Imperviousness and NLCD 2001 Tree Canopy layers were used as ancillary data sources in the Cropland Data Layer classification process. More information on the NLCD 2006 can be found at <http://www.mrlc.gov/>. Refer to the 'Supplemental Information' Section of this metadata file for the complete list of ancillary data sources used as classification inputs.
Source_Scale_Denominator: 30 meter
Type_of_Source_Media: online
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: unknown
Source_Currentness_Reference: ground condition
Source_Contribution:
spatial and attribute information used in the spectral signature training and validation of non-agricultural land cover
Source_Information:
Source_Citation:
Citation_Information:
Originator:
United States Department of Agriculture (USDA), Farm Service Agency (FSA)
Title: USDA, FSA Common Land Unit (CLU)
Geospatial_Data_Presentation_Form: vector digital data
Publication_Information:
Publisher: USDA, FSA Aerial Photography Field Office

Publication_Place: Salt Lake City, Utah 84119-2020 USA
Publication_Date: 2008
Other_Citation_Details:
Access to the USDA, Farm Service Agency (FSA) Common Land Unit (CLU) digital data set is currently limited to FSA and Agency partnerships. During the current growing season, producers enrolled in FSA programs report their growing intentions, crops and acreage to USDA Field Service Centers. Their field boundaries are digitized in a standardized GIS data layer and the associated attribute information is maintained in a database known as 578 Administrative Data. This CLU/578 dataset provides a comprehensive and robust agricultural training and validation data set for the Cropland Data Layer. Additional information about the CLU Program can be found at <http://www.fsa.usda.gov/>.
Source_Scale_Denominator: 1:4800
Type_of_Source_Media: online
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: unknown
Source_Currentness_Reference: ground condition, updated annually
Source_Contribution:
spatial and attribute information used in the spectral signature training and validation of agricultural land cover
Source_Information:
Source_Citation:
Citation_Information:
Originator:
United States Department of Interior, Bureau of Reclamation, Lower Colorado Region
Title:
Lower Colorado River Water Accounting System (LCRAS) GIS data layer

Geospatial_Data_Presentation_Form: vector digital data
Publication_Information:
Publisher:
United States Department of Interior, Bureau of Reclamation, Lower Colorado Region

Publication_Place: Boulder City, NV 89006-1470, USA
Publication_Date: 2008
Other_Citation_Details:
The Lower Colorado River Water Accounting System (LCRAS) GIS data layer contains an annually updated record of crop types that was used to supplement the training and validation of the Cropland Data Layer. The area covered is Southern California and Southwest Arizona. For more details please reference the Bureau of Reclamation website <http://www.usbr.gov/lc/>.
Source_Scale_Denominator: 1:4800
Type_of_Source_Media: online
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: unknown
Source_Currentness_Reference: ground condition, updated annually
Source_Contribution:
spatial and attribute information used in the spectral signature training and validation of agricultural land cover
Process_Step:
Process_Description:
OVERVIEW: The United States Department of Agriculture (USDA), National Agricultural Statistics Service (NASS) Cropland Data Layer (CDL) Program is a unique agricultural-specific land cover geospatial product that is reproduced annually in participating states. The CDL Program builds upon NASS' traditional crop acreage estimation program and integrates Farm Service Agency (FSA) grower-reported field data with satellite imagery to create an unbiased statistical estimator of crop area at the state and county level for internal use. It is important to note that the internal acreage estimates produced using the CDL are not simple pixel counting. It is more of an 'Adjusted Census by Satellite.'

SOFTWARE: ERDAS Imagine is used in the pre- and post- processing of all raster-based data. ESRI ArcGIS is used to prepare the vector-based training and validation data. Rulequest See5.0 is used to create a decision tree based classifier. The NLCD Mapping Tool is used to apply the See5.0 decision-tree via ERDAS Imagine.

DECISION TREE CLASSIFIER: This Cropland Data Layer used the decision tree classifier approach. Using a decision tree classifier is a departure from older versions of the CDL which were created using in-house software (Peditor) based upon a maximum likelihood classifier approach. Check the 'Process Description' section of the specific state and year metadata file to verify the methodology used. Decision trees offer several advantages over the more traditional maximum likelihood classification method. The advantages include being: 1) non-parametric by nature and thus not reliant on the assumption of the input data being normally distributed, 2) efficient to construct and thus capable of handling large and complex data sets, 3) able to incorporate missing and non-continuous data, and 4) able to sort out non-linear relationships.

GROUND TRUTH: As with the maximum likelihood method, decision tree analysis is a supervised classification technique. Thus, it relies on having a sample of known ground truth areas in which to train the classifier. Older versions of the CDL (prior to 2006) utilized ground truth data from the annual June Agricultural Survey (JAS). Beginning in 2006, the CDL utilizes the very comprehensive ground truth data provided from the FSA Common Land Unit (CLU) Program as a replacement for the JAS data. The FSA CLU data have the advantage of natively being in a GIS and containing magnitudes more of field level information. Disadvantages include that it is not truly a probability sample of land cover and has bias toward subsidized program crops. Additional information about the FSA data can be found at <http://www.fsa.usda.gov/>.

INPUTS: The CDL is produced using satellite imagery from the Landsat 5 TM sensor, Landsat 7 ETM+ sensor, and the Indian Remote Sensing RESOURCESAT-1 (IRS-P6) Advanced Wide Field Sensor (AWiFS) collected during the current growing season. For the 2008 CDL Program, the AWiFS imagery was resampled to 30 meters to match the Landsat spatial resolution. The resample used bilinear interpolation, polynomial approximation, polynomial order of 3. Some CDL states used additional satellite imagery and ancillary inputs to supplement and improve the classification. These additional sources can include the United States Geological Survey (USGS) National Elevation Dataset (NED), the USGS National Land Cover Database 2006 (NLCD 2006), and the National Aeronautics and Space Administration (NASA) Moderate Resolution Imaging Spectroradiometer (MODIS) 250 meter 16 day Normalized Difference Vegetation Index (NDVI) composites. Please refer to the 'Supplemental_Information' Section of this metadata file for a complete list of all imagery and ancillary data used to generate this state's CDL.

ACCURACY: The accuracy of the land cover classifications are evaluated using independent validations data sets generated from the FSA CLU data (agricultural categories) and the NLCD 2006 (non-agricultural categories). The Producer's Accuracy is generally 85% to 95% correct for the major crop-specific land cover categories. See the 'Attribute Accuracy Report' section of this metadata file for the full accuracy report.

PUBLIC RELEASE: The USDA, NASS Cropland Data Layer is considered public domain and free to redistribute. The official website is <http://www.nass.usda.gov/research/Cropland/SARS1a.htm>. The data is available free for download through CropScape <http://nassgeodata.gmu.edu/CropScape/> and the Geospatial Data Gateway <http://datagateway.nrcs.usda.gov/>. See the 'Ordering Instructions' section of this metadata file for detailed download instructions. Please note that in no case are farmer reported data revealed or derivable from the public use Cropland Data Layer.
Process_Date: 2008
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: USDA, NASS, Spatial Analysis Research Section
Contact_Person: USDA, NASS, Spatial Analysis Research Section staff
Contact_Address:
Address_Type: mailing and physical address
Address: 3251 Old Lee Highway, Room 305
City: Fairfax
State_or_Province: Virginia
Postal_Code: 22030-1504
Country: USA
Contact_Voice_Telephone: 703-877-8000
Contact_Facsimile_Telephone: 703-877-8044
Contact_Electronic_Mail_Address: HQ_RDD_GIB@nass.usda.gov
Cloud_Cover:
Generally, there is enough cloud-free satellite imagery available during the growing season that there will be no cloud cover in the published CDL. Older versions of the CDL (prior to 2006) may contain significant cloud cover due to available imagery and processing limitations, which have since been overcome. Reference the attribute information within the specific CDL state and year image file to verify the extent of cloud cover.
Spatial_Data_Organization_Information:
Indirect_Spatial_Reference: California
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Pixel
Row_Count: 35841

Column_Count: 29767

Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name:
FOR GEOSPATIAL DATA GATEWAY USERS: Universal Transverse Mercator (UTM) Due to technical restrictions, the online data available free for download through the Geospatial Data Gateway <http://datagateway.nrcs.usda.gov/> can only be offered in UTM. However, the official Cropland Data Layer available at <http://nassgeodata.gmu.edu/CropScape/> includes the data in its native Albers Conical Equal Area coordinate system.

FOR CROPSCAPE USERS: Albers Conical Equal Area is the native projection used in the production of the Cropland Data Layer. The projection parameters for the Albers projection are as follows: 
Map_Projection_Name: Albers Conical Equal Area
Albers_Conical_Equal_Area:
Standard_Parallel: 29.500000
Standard_Parallel: 45.500000
Longitude_of_Central_Meridian: -96.000000
Latitude_of_Projection_Origin: 23.000000
False_Easting: 0.000000
False_Northing: 0.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: row and column
Coordinate_Representation:
Abscissa_Resolution: 56
Ordinate_Resolution: 56
Planar_Distance_Units: meters
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257223563
Universal_Transverse_Mercator:
UTM_Zone_Number: 11 North
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.9996
Longitude_of_Central_Meridian: -117
Latitude_of_Projection_Origin: 0
False_Easting: 500000
False_Northing: 0
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 30
Ordinate_Resolution: 30
Planar_Distance_Units: meters
Geodetic_Model:
Horizontal_Datum_Name: WGS84
Ellipsoid_Name: WGS84
Semi-major_Axis: 6378137.00

Denominator_of_Flattening_Ratio: 298.257223563
Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
The Cropland Data Layer (CDL) is produced using agricultural training data from the Farm Service Agency (FSA) Common Land Unit (CLU) Program and non-agricultural training data from the United States Geological Survey (USGS) National Land Cover Database 2006 (NLCD 2006). The strength and emphasis of the CDL is crop-specific land cover categories. The accuracy of the CDL non-agricultural land cover classes are entirely dependent upon the NLCD. Thus, the USDA, NASS recommends that users consider the NLCD for studies involving non-agricultural land cover.
Entity_and_Attribute_Detail_Citation:
If the following table does not display properly, then please visit the following website to view the original metadata file <http://www.nass.usda.gov/research/Cropland/metadata/meta.htm>. 
 Data Dictionary: USDA, National Agricultural Statistics Service, 2008 Cropland Data Layer

 Source: USDA, National Agricultural Statistics Service

 The following is a cross reference list of the categorization codes and land covers.
 Note that not all land cover categories listed below will appear in an individual state.

 Raster
 Attribute Domain Values and Definitions: NO DATA, BACKGROUND 0

 Categorization Code   Land Cover
         "0"       Background

 Raster
 Attribute Domain Values and Definitions: CROPS 1-20

 Categorization Code   Land Cover
           "1"       Corn
           "2"       Cotton
           "3"       Rice
           "4"       Sorghum
           "5"       Soybeans
           "6"       Sunflower
          "10"       Peanuts
          "11"       Tobacco
          "12"       Sweet Corn
          "13"       Pop or Orn Corn
          "14"       Mint

 Raster
 Attribute Domain Values and Definitions: GRAINS,HAY,SEEDS 21-40

 Categorization Code   Land Cover
          "21"       Barley
          "22"       Durum Wheat
          "23"       Spring Wheat
          "24"       Winter Wheat
          "25"       Other Small Grains
          "26"       Dbl Crop WinWht/Soybeans
          "27"       Rye
          "28"       Oats
          "29"       Millet
          "30"       Speltz
          "31"       Canola
          "32"       Flaxseed
          "33"       Safflower
          "34"       Rape Seed
          "35"       Mustard
          "36"       Alfalfa
          "37"       Other Hay/Non Alfalfa
          "38"       Camelina
          "39"       Buckwheat

 Raster
 Attribute Domain Values and Definitions: CROPS 41-60

 Categorization Code   Land Cover
          "41"       Sugarbeets
          "42"       Dry Beans
          "43"       Potatoes
          "44"       Other Crops
          "45"       Sugarcane
          "46"       Sweet Potatoes
          "47"       Misc Vegs & Fruits
          "48"       Watermelons
          "49"       Onions
          "50"       Cucumbers
          "51"       Chick Peas
          "52"       Lentils
          "53"       Peas
          "54"       Tomatoes
          "55"       Caneberries
          "56"       Hops
          "57"       Herbs
          "58"       Clover/Wildflowers
          "59"       Sod/Grass Seed
          "60"       Switchgrass

 Raster
 Attribute Domain Values and Definitions: NON-CROP 61-65

 Categorization Code   Land Cover
          "61"       Fallow/Idle Cropland
          "62"       Pasture/Grass
          "63"       Forest
          "64"       Shrubland
          "65"       Barren

 Raster
 Attribute Domain Values and Definitions: CROPS 66-80

 Categorization Code   Land Cover
          "66"       Cherries
          "67"       Peaches
          "68"       Apples
          "69"       Grapes
          "70"       Christmas Trees
          "71"       Other Tree Crops
          "72"       Citrus
          "74"       Pecans
          "75"       Almonds
          "76"       Walnuts
          "77"       Pears

 Raster
 Attribute Domain Values and Definitions: OTHER 81-109

 Categorization Code   Land Cover
          "81"       Clouds/No Data
          "82"       Developed
          "83"       Water
          "87"       Wetlands
          "88"       Nonag/Undefined
          "92"       Aquaculture

 Raster
 Attribute Domain Values and Definitions: NLCD-DERIVED CLASSES 110-195

 Categorization Code   Land Cover
         "111"       Open Water
         "112"       Perennial Ice/Snow
         "121"       Developed/Open Space
         "122"       Developed/Low Intensity
         "123"       Developed/Med Intensity
         "124"       Developed/High Intensity
         "131"       Barren
         "141"       Deciduous Forest
         "142"       Evergreen Forest
         "143"       Mixed Forest
         "152"       Shrubland
         "171"       Grassland Herbaceous
         "181"       Pasture/Hay
         "190"       Woody Wetlands
         "195"       Herbaceous Wetlands

 Raster
 Attribute Domain Values and Definitions: CROPS 195-255

 Categorization Code   Land Cover
         "204"       Pistachios
         "205"       Triticale
         "206"       Carrots
         "207"       Asparagus
         "208"       Garlic
         "209"       Cantaloupes
         "210"       Prunes
         "211"       Olives
         "212"       Oranges
         "213"       Honeydew Melons
         "214"       Broccoli
         "216"       Peppers
         "217"       Pomegranates
         "218"       Nectarines
         "219"       Greens
         "220"       Plums
         "221"       Strawberries
         "222"       Squash
         "223"       Apricots
         "224"       Vetch
         "225"       Dbl Crop WinWht/Corn
         "226"       Dbl Crop Oats/Corn
         "227"       Lettuce
         "229"       Pumpkins
         "230"       Dbl Crop Lettuce/Durum Wht
         "231"       Dbl Crop Lettuce/Cantaloupe
         "232"       Dbl Crop Lettuce/Cotton
         "233"       Dbl Crop Lettuce/Barley
         "234"       Dbl Crop Durum Wht/Sorghum
         "235"       Dbl Crop Barley/Sorghum
         "236"       Dbl Crop WinWht/Sorghum
         "237"       Dbl Crop Barley/Corn
         "238"       Dbl Crop WinWht/Cotton
         "239"       Dbl Crop Soybeans/Cotton
         "240"       Dbl Crop Soybeans/Oats
         "241"       Dbl Crop Corn/Soybeans
         "242"       Blueberries
         "243"       Cabbage
         "244"       Cauliflower
         "245"       Celery
         "246"       Radishes
         "247"       Turnips
         "248"       Eggplants
         "249"       Gourds
         "250"       Cranberries
         "254"       Dbl Crop Barley/Soybeans
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: USDA, NASS Customer Service
Contact_Person: USDA, NASS Customer Service Staff
Contact_Address:
Address_Type: mailing and physical address
Address: 1400 Independence Avenue, SW, Room 5038-S
City: Washington
State_or_Province: District of Columbia
Postal_Code: 20250-9410
Country: USA
Contact_Voice_Telephone: 800-727-9540
Contact_Facsimile_Telephone: 703-877-8044
Contact_Electronic_Mail_Address: HQ_RDD_GIB@nass.usda.gov
Contact_Instructions:
Please visit the official website <http://www.nass.usda.gov/research/Cropland/SARS1a.htm> for distribution details. The Cropland Data Layer is available free for download at <http://nassgeodata.gmu.edu/CropScape/> and <http://datagateway.nrcs.usda.gov/>. Distribution issues can also be directed to the NASS Customer Service Hotline at 1-800-727-9540.
Resource_Description: Cropland Data Layer - California 2008
Distribution_Liability:
Disclaimer: Users of the Cropland Data Layer (CDL) are solely responsible for interpretations made from these products. The CDL is provided 'as is' and the USDA, NASS does not warrant results you may obtain using the Cropland Data Layer. Contact our staff at (HQ_RDD_GIB@nass.usda.gov) if technical questions arise in the use of the CDL. NASS does maintain a Frequently Asked Questions (FAQ's) section on the CDL website at <http://www.nass.usda.gov/research/Cropland/SARS1a.htm>.

Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: GEOTIFF
Format_Version_Date: California 2008
Format_Information_Content: GEOTIFF
Transfer_Size:
The image file size will vary depending on the state and completeness of coverage. The user can specify the state, or a user-defined area of interest, and year(s) of CDL data to download at the Cropscape website <http://nassgeodata.gmu.edu/CropScape/>.
When downloading the data through the Geospatial Data Gateway <http://datagateway.nrcs.usda.gov/> all available years of CDL production for the requested state are included in one compressed file. Technical restrictions do not allow us to offer the CDL by individual state/year through the Geospatial Data Gateway. See the 'Ordering Instructions' section of this metadata file for additional information.
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: <http://nassgeodata.gmu.edu/CropScape/>
Access_Instructions:
The CDL is available online and free for download from the Cropscape website <http://nassgeodata.gmu.edu/CropScape/>. It is also available free for download from the Geospatial Data Gateway website <http://datagateway.nrcs.usda.gov/>. See the 'Ordering Instructions' section of this metadata file for detailed Geospatial Data Gateway download instructions.
Fees:
Please visit the official website <http://www.nass.usda.gov/research/Cropland/SARS1a.htm> for distribution details. The Cropland Data Layer is available free for download at <http://nassgeodata.gmu.edu/CropScape/> and <http://datagateway.nrcs.usda.gov/>. Distribution issues can also be directed to the NASS Customer Service Hotline at 1-800-727-9540.
Ordering_Instructions:
The CDL is available online and free for download from the Cropscape website <http://nassgeodata.gmu.edu/CropScape/>. The Cropland Data Layer is also available free for download from the NRCS Geospatial Data Gateway at <http://datagateway.nrcs.usda.gov/>.

IMPORTANT NOTE: When downloading the CDL using the NRCS Geospatial Data Gateway all available years of CDL production for the requested state are included in a single compressed file. Geospatial Data Gateway technical restrictions do not allow us to offer the CDL by individual state/year. We are working on offering this option in the future. 
Instructions for downloading from the NRCS Geospatial Data Gateway:

Start by clicking on 'Get Data'

Then click on 'Quick State'

Scroll down to choose your state and click 'Continue'

Choose 'Land_use_land_cover' and select 'Cropland Data Layer by State' and 'Continue to Step3'

Choose 'Continue' to Step4

Lastly, you are given the option to download the data for free.
Custom_Order_Process:
For a list of other states and years of available data please visit: <http://www.nass.usda.gov/research/Cropland/SARS1a.htm>. The Cropland Data Layer is available free for download at <http://nassgeodata.gmu.edu/CropScape/> and <http://datagateway.nrcs.usda.gov/>. Distribution issues can also be directed to the NASS Customer Service Hotline at 1-800-727-9540.
Technical_Prerequisites:
If the user does not have software capable of viewing a GEOTIF (.tif) file format then we suggest using the Cropscape website <http://nassgeodata.gmu.edu/CropScape/> or using the freeware browser ESRI ArcGIS Explorer <http://www.esri.com/>.
Metadata_Reference_Information:
Metadata_Date: 20120131
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: USDA, NASS, Spatial Analysis Research Section
Contact_Person: USDA, NASS, Spatial Analysis Research Section Staff
Contact_Address:
Address_Type: mailing and physical address
Address: 3251 Old Lee Highway, Room 305
City: Fairfax
State_or_Province: Virginia
Postal_Code: 22030-1504
Country: USA
Contact_Voice_Telephone: 703-877-8000
Contact_Facsimile_Telephone: 703-877-8044
Contact_Electronic_Mail_Address: HQ_RDD_GIB@nass.usda.gov
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Access_Constraints: No restrictions on the distribution or use of the metadata file
Metadata_Use_Constraints: No restrictions on the distribution or use of the metadata file
Generated by mp version 2.9.12 on Fri Jan 27 20:45:15 2012