This dataset, part of the NASA Making Earth System Data Records for Use in Research Environments (MEaSUREs) program, consists of mean monthly velocity maps for selected glacier outlet areas. The maps are generated by tracking visible features between optical image pairs acquired by the Landsat 4 and 5 Thematic Mapper (TM), the Landsat 7 Enhanced Thematic Mapper Plus (ETM+), the Landsat 8 Operational Land Imager (OLI), and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER).
Note
Monthly means are calculated from images, which may have acquisition dates from the preceding or succeeding month. For the naming convention, the month is determined from where the midpoint Julian dates fall. For example, September monthly means may have been generated from images that were acquired in August or in October but the midpoint Julian date between the images falls within September. The exact dates used are included as per-image metadata fields.
该数据集是美国宇航局在研究环境中使用地球系统数据记录 (MEaSUREs) 计划的一部分，包括选定冰川出口区域的月平均速度图。这些地图是通过跟踪由 Landsat 4 和 5 主题制图仪 (TM)、Landsat 7 Enhanced Thematic Mapper Plus (ETM+)、Landsat 8 Operational Land Imager (OLI) 和 Advanced Spaceborne 获取的光学图像对之间的可见特征生成的热发射和反射辐射计 (ASTER)。
笔记
每月均值是根据图像计算得出的，这些图像可能具有上个月或下个月的采集日期。对于命名约定，月份是从儒略日期中点所在的位置确定的。例如，9 月的月均值可能是从 8 月或 10 月获取的图像生成的，但图像之间的儒略日期中点落在 9 月内。使用的确切日期包含在每个图像元数据字段中。
一般文件
Dataset Availability
1985-03-01T00:00:00 - 2016-09-30T00:00:00
Dataset Provider
Collection Snippet
ee.ImageCollection("OSU/GIMP/ICE_VELOCITY_OPT")
Resolution
100 meters
Bands Table
| Name | Description | Units |
| velocity_x | Ice flow x velocity | meter/year |
| velocity_y | Ice flow y velocity | meter/year |
| error_x | Ice flow x error | meter/year |
| error_y | Ice flow y error | meter/year |
影响属性：
| Name | Type | Descript on |
| CENTRAL_JULIAN_DATES | List of Strings | List of central Julian date for image pairs used in image. |
| FIRST_IMAGE_DATES | List of Strings | List of first image dates used in image. |
| NOMINAL_TIMES | List of Strings | List of nominal observation times for pairs of images. |
| PRODUCTION_DATE | String | Production date. |
| SECOND_IMAGE_DATES | List of Strings | List of second image dates used in image. |
| SENSORS | List of Strings | List of sensor pairs used in image. |
i数据引用：
Howat, I. 2017. MEaSUREs Greenland Ice Velocity: Selected Glacier Site Velocity Maps from Optical Images, Version 2. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi:10.5067/VM5DZ20MYF5C. [Date Accessed].
代码：
var dataset = ee.ImageCollection('OSU/GIMP/ICE_VELOCITY_OPT') .filter(ee.Filter.date('2016-01-01', '2016-09-15')); var iceVelocityVis = { min: [0.0, 0.0, 0.0], max: [-1000.0, 0.0, 1000.0], bands: ['velocity_x', 'velocity_x', 'velocity_x'], }; Map.setCenter(-66.82, 76.151, 7); Map.addLayer(dataset, iceVelocityVis, 'Ice Velocity');
