USDA, National Agricultural Statistics Service, 2018 Crop Frequency LAYERS FOR CORN, COTTON, SOYBEANS AND WHEAT
BASED ON THE 2008-2018 CROPLAND DATA LAYERS (11 YEARS OF DATA)
NATIONAL ACCURACY REPORTS
CORN
Cover Attribute *Correct Producer's Omission User's Commission Cond'l
Type Code Pixels Accuracy Error Kappa Accuracy Error Kappa
---- ---- -------- --------- ----- ----- -------- ------- -----
Planted 1 time in 11 YEARS 1 2,556,930 81.8% 18.2% 0.810 76.9% 23.1% 0.759
Planted 2 times in 11 YEARS 2 2,123,660 74.9% 25.1% 0.739 76.7% 23.3% 0.758
Planted 3 times in 11 YEARS 3 2,482,040 75.6% 24.4% 0.745 74.7% 25.3% 0.736
Planted 4 times in 11 YEARS 4 3,283,250 71.9% 28.1% 0.702 74.5% 25.5% 0.729
Planted 5 times in 11 YEARS 5 12,866,500 88.0% 12.0% 0.853 89.1% 10.9% 0.866
Planted 6 times in 11 YEARS 6 13,091,800 91.8% 8.2% 0.898 90.1% 9.9% 0.878
Planted 7 times in 11 YEARS 7 3,769,630 88.6% 11.4% 0.879 83.4% 16.6% 0.824
Planted 8 times in 11 YEARS 8 2,547,850 90.7% 9.3% 0.903 88.7% 11.3% 0.882
Planted 9 times in 11 YEARS 9 1,685,270 90.6% 9.4% 0.904 89.7% 10.3% 0.895
Planted 10 times in 11 YEARS 10 1,123,370 91.3% 8.7% 0.911 89.0% 11.0% 0.888
Planted 11 times in 11 YEARS 11 1,319,110 92.6% 7.4% 0.925 97.4% 2.6% 0.973
COTTON
Cover Attribute *Correct Producer's Omission User's Commission Cond'l
Type Code Pixels Accuracy Error Kappa Accuracy Error Kappa
---- ---- -------- --------- ----- ----- -------- ------- -----
Planted 1 time in 11 YEARS 1 480,631 82.6% 17.4% 0.824 72.3% 27.7% 0.720
Planted 2 times in 11 YEARS 2 302,682 82.6% 17.4% 0.825 78.3% 21.7% 0.782
Planted 3 times in 11 YEARS 3 193,293 78.1% 21.9% 0.780 76.7% 23.3% 0.767
Planted 4 times in 11 YEARS 4 150,708 74.6% 25.4% 0.745 77.4% 22.6% 0.774
Planted 5 times in 11 YEARS 5 122,743 75.2% 24.8% 0.752 78.6% 21.4% 0.785
Planted 6 times in 11 YEARS 6 98,535 75.9% 24.1% 0.759 79.2% 20.8% 0.791
Planted 7 times in 11 YEARS 7 61,035 74.3% 25.7% 0.743 73.4% 26.6% 0.733
Planted 8 times in 11 YEARS 8 52,124 72.8% 27.2% 0.728 75.2% 24.8% 0.752
Planted 9 times in 11 YEARS 9 45,104 73.9% 26.1% 0.739 74.3% 25.7% 0.742
Planted 10 times in 11 YEARS 10 46,739 82.0% 18.0% 0.820 77.1% 22.9% 0.771
Planted 11 times in 11 YEARS 11 63,602 85.6% 14.4% 0.856 95.4% 4.6% 0.954
SOYBEANS
Cover Attribute *Correct Producer's Omission User's Commission Cond'l
Type Code Pixels Accuracy Error Kappa Accuracy Error Kappa
---- ---- -------- --------- ----- ----- -------- ------- -----
Planted 1 time in 11 YEARS 1 2,273,100 82.0% 18.0% 0.813 79.8% 20.2% 0.790
Planted 2 times in 11 YEARS 2 2,578,890 82.2% 17.8% 0.814 82.9% 17.1% 0.821
Planted 3 times in 11 YEARS 3 3,456,350 83.4% 16.6% 0.824 83.2% 16.8% 0.823
Planted 4 times in 11 YEARS 4 4,959,320 78.8% 21.2% 0.770 81.7% 18.3% 0.801
Planted 5 times in 11 YEARS 5 14,558,900 88.5% 11.5% 0.854 89.6% 10.4% 0.868
Planted 6 times in 11 YEARS 6 12,488,600 90.4% 9.6% 0.882 89.2% 10.8% 0.868
Planted 7 times in 11 YEARS 7 1,987,610 79.0% 21.0% 0.782 72.3% 27.7% 0.713
Planted 8 times in 11 YEARS 8 932,707 76.2% 23.8% 0.758 72.4% 27.6% 0.720
Planted 9 times in 11 YEARS 9 449,526 70.2% 29.8% 0.700 66.8% 33.2% 0.665
Planted 10 times in 11 YEARS 10 323,160 76.0% 24.0% 0.759 66.4% 33.6% 0.662
Planted 11 times in 11 YEARS 11 354,239 84.7% 15.3% 0.846 79.7% 20.3% 0.796
WHEAT
Cover Attribute *Correct Producer's Omission User's Commission Cond'l
Type Code Pixels Accuracy Error Kappa Accuracy Error Kappa
---- ---- -------- --------- ----- ----- -------- ------- -----
Planted 1 time in 11 YEARS 1 3,879,640 85.8% 14.2% 0.849 83.9% 16.1% 0.829
Planted 2 times in 11 YEARS 2 2,444,970 70.5% 29.5% 0.693 79.7% 20.3% 0.787
Planted 3 times in 11 YEARS 3 2,265,300 66.5% 33.5% 0.650 69.2% 30.8% 0.678
Planted 4 times in 11 YEARS 4 2,644,900 68.1% 31.9% 0.665 70.0% 30.0% 0.684
Planted 5 times in 11 YEARS 5 3,571,380 78.0% 22.0% 0.766 74.7% 25.3% 0.731
Planted 6 times in 11 YEARS 6 2,893,960 82.1% 17.9% 0.812 77.0% 23.0% 0.759
Planted 7 times in 11 YEARS 7 1,052,840 70.3% 29.7% 0.697 68.1% 31.9% 0.675
Planted 8 times in 11 YEARS 8 753,325 68.3% 31.7% 0.678 65.5% 34.5% 0.650
Planted 9 times in 11 YEARS 9 604,068 58.6% 41.4% 0.580 62.1% 37.9% 0.616
Planted 10 times in 11 YEARS 10 566,767 66.2% 33.8% 0.658 62.7% 37.3% 0.623
Planted 11 times in 11 YEARS 11 1,515,430 90.3% 9.7% 0.901 78.4% 21.6% 0.779
*Correct Pixels represents the total number of independent validation pixels correctly identified in the error matrix.
Attribute_Accuracy_Value:
The Crop Frequency Layer is based on the Cropland Data Layer (CDL). The classification accuracy of the original CDLs 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 accuracy assessment of the Crop Frequency Layers use the entire FSA CLU data (agricultural categories) that was used in the training and validation of the original Cropland Data Layers (CDL). Only FSA data that exists in all 11 years (2008-2018) is used for validating the Crop Frequency Layers. See the 'Attribute Accuracy Report' section of this metadata file for the full accuracy report.
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.