| タイトル | Optimal spatial sampling techniques for ground truth data in microwave remote sensing of soil moisture |
| 著者（英） | Ulaby, F. T.; Rao, R. G. S. |
| 著者所属（英） | Kansas Univ. Center for Research, Inc. |
| 発行日 | 1977-01-01 |
| 言語 | eng |
| 内容記述 | The paper examines optimal sampling techniques for obtaining accurate spatial averages of soil moisture, at various depths and for cell sizes in the range 2.5-40 acres, with a minimum number of samples. Both simple random sampling and stratified sampling procedures are used to reach a set of recommended sample sizes for each depth and for each cell size. Major conclusions from statistical sampling test results are that (1) the number of samples required decreases with increasing depth; (2) when the total number of samples cannot be prespecified or the moisture in only one single layer is of interest, then a simple random sample procedure should be used which is based on the observed mean and SD for data from a single field; (3) when the total number of samples can be prespecified and the objective is to measure the soil moisture profile with depth, then stratified random sampling based on optimal allocation should be used; and (4) decreasing the sensor resolution cell size leads to fairly large decreases in samples sizes with stratified sampling procedures, whereas only a moderate decrease is obtained in simple random sampling procedures. |
| NASA分類 | EARTH RESOURCES AND REMOTE SENSING |
| レポートNO | 78A18247 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/434302 |
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