简介
澳大利亚数字地球（DEA）水观测使用一种算法将大地遥感卫星图像中的每个像素分为 "湿"、"干 "或 "无效"。水观测统计提供的信息包括每年大地遥感卫星能够清晰观测到某一区域的次数、这些观测结果中潮湿的次数，以及这意味着在地貌中观测到水的时间百分比。
将分类像素合并成涵盖每年的摘要，就能得到通常有水和很少有水的地方的信息。由于没有对该产品进行置信度过滤，它受到输入的水分类中出现的误分类噪音的影响，很难单独进行解释。
如需了解更多信息：
https://cmi.ga.gov.au/data-products/dea/686/dea-water-observations-statistics-landsat
该产品是澳大利亚数字地球计划的一部分
Digital Earth Australia Home | Digital Earth Australia | Geoscience Australia
数据介绍
Catalog Owner
Geoscience Australia
Dataset Availability
1987-01-01T00:00:00Z–2022-01-01T00:00:00Z
Dataset Provider
Contact
https://www.ga.gov.au/contact-us
Earth Engine Snippet
ee.ImageCollection("projects/geoscience-aus-cat/assets/ga_ls_wo_fq_cyear_3")
DEA Water Observations Statistics (Landsat)
Geoscience Australia Landsat Water Observation Statistics Collection 3
Version:
3.1.6 (Latest)
Product types:
Derivative, Raster
Time span:
1986 – Present
Update frequency:
Periodically
Product IDs:
ga_ls_wo_fq_apr_oct_3, ga_ls_wo_fq_nov_mar_3, ga_ls_wo_fq_cyear_3, ga_ls_wo_fq_myear_3
Resolution
25 meters
波段
| Name | Min | Max | Wavelength | Description |
|---|---|---|---|---|
blue |
0* | 10000* | 0.450-0.520 μm | Band blue surface reflectance geometric median. |
green |
0* | 10000* | 0.520-0.600 μm | Band green surface reflectance geometric median. |
red |
0* | 10000* | 0.630-0.690 μm | Band red surface reflectance geometric median. |
near_infrared |
0* | 10000* | 0.760-0.900 μm | Band near infrared surface reflectance geometric median. |
shortwave_infrared_1 |
0* | 10000* | 1.550-1.750 μm | Band shortwave infrared 1 surface reflectance geometric median. |
shortwave_infrared_2 |
0* | 10000* | 2.080-2.350 μm | Band shortwave infrared 2 surface reflectance geometric median. |
Euclidean_distance_median_absolute_deviation |
0* | 10000* | The Median Absolute Deviation using Euclidean distance (EMAD). EMAD is more sensitive to changes in target brightness. |
|
spectral_distance_median_absolute_deviation |
0* | 10000* | The Median Absolute Deviation using Cosine (spectral) distance (SMAD). SMAD is more sensitive to change in target spectral response. |
|
Bray_Curtis_dissimilarity_median_absolute_deviation |
0* | 10000* | The Median Absolute Deviation using Bray Curtis dissimilarity (BCMAD). BCMAD is more sensitive to the distribution of the observation values through time. |
|
count |
0* | 400* | The number of the available pixels used for calculation per calendar year. |
* estimated min or max value
代码
var water_obs = ee.ImageCollection('projects/geoscience-aus-cat/assets/ga_ls_wo_fq_cyear_3');
var gray = 150;
var background = ee.Image.rgb(gray, gray, gray).visualize({ min: 0, max: 255 });
var visualization_frequency = {
bands: ['frequency'],
min: 0.0,
max: 1.0,
palette: ['ffffff', 'ffbbbb', '0000ff']
};
var point = ee.Geometry.Point([113.651455, -26.024137]);
var image = water_obs.filterBounds(point)
.filterDate('2010-01-01', '2011-01-01')
.first()
.visualize(visualization_frequency);
Map.centerObject(image, 12);
var imageWithBackground = ee.ImageCollection([background, image]).mosaic();
Map.addLayer(imageWithBackground, {}, 'Water Frequency ratio');引用
Mueller, N., Lewis, A., Roberts, D., Ring, S., Melrose, R., Sixsmith, J., Lymburner, L., McIntyre, A., Tan, P., Curnow, S., & Ip, A. (2016). Water observations from space: Mapping surface water from 25 years of Landsat imagery across Australia. Remote Sensing of Environment, 174, 341-352 https://cmi.ga.gov.au/data-products/dea/686/dea-water-observations-statistics-landsat
结果
