简介
Landsat8 TOA数据集是将数据每个波段的辐射亮度值转换为大气层顶表观反射率TOA,是飞行在大气层之外的航天传感器量测的反射率,包括了云层、气溶胶和气体的贡献,可通过辐射亮度定标参数、太阳辐照度、太阳高度角和成像时间等几个参数计算得到。为了便于在线分析存储,平台将影像像素值扩大了10000倍。前言 – 人工智能教程 Landsat-8卫星包含OLI(Operational Land Imager 陆地成像仪)和TIRS(Thermal Infrared Sensor 热红外传感器)两种传感器,每16天可以实现一次全球覆盖。 OLI包括9个波段,空间分辨率为30米,其中包括一个15米的全色波段,成像宽幅为185x185km。TIRS用于收集地球两个热区地带的热量流失,能够了解所观测地带水分消耗。
数据集ID:
LC08/02/T1
时间范围: 2022年01月-现在
范围: 全国
来源: USGS
复制代码段:
var images = pie.ImageCollection("LC08/02/T1")
名称 | 比例因子 | 分辨率 | 波段范围(μm) | 描述信息 |
---|---|---|---|---|
B1 | 0.0001 | 30m | 0.43-0.45μm | Coastal |
B2 | 0.0001 | 30m | 0.45-0.51μm | Blue |
B3 | 0.0001 | 30m | 0.53-0.59μm | Green |
B4 | 0.0001 | 30m | 0.64-0.67μm | Red |
B5 | 0.0001 | 30m | 0.85-0.88μm | NIR |
B6 | 0.0001 | 30m | 1.57-1.65μm | SWIR 1 |
B7 | 0.0001 | 30m | 2.11-2.29μm | SWIR 2 |
B8 | 0.0001 | 15m | 0.50-0.68μm | Pan |
B9 | 0.0001 | 30m | 1.36-1.38μm | Cirrus |
B10 | 0.0001 | 100m | 10.6-11.19μm | TIRS 1 |
B11 | 0.0001 | 100m | 11.5-12.51μm | TIRS 2 |
QA_PIXEL | -- | -- | -- | QA Bitmask |
Bitmask for BQA | |
---|---|
Bit 0: Designated Fill 0: No1: YesBit 1: Terrain Occlusion 0: No1: YesBits 2-3: Radiometric Saturation 0: No bands contain saturation1: 1-2 bands contain saturation2: 3-4 bands contain saturation3: 5 or more bands contain saturationBit 4: Cloud 0: No1: YesBits 5-6: Cloud Confidence 0: Not Determined / Condition does not exist.1: Low, (0-33 percent confidence)2: Medium, (34-66 percent confidence)3: High, (67-100 percent confidence)Bits 7-8: Cloud Shadow Confidence 0: Not Determined / Condition does not exist.1: Low, (0-33 percent confidence)2: Medium, (34-66 percent confidence)3: High, (67-100 percent confidence)Bits 9-10: Snow / Ice Confidence 0: Not Determined / Condition does not exist.1: Low, (0-33 percent confidence)2: Medium, (34-66 percent confidence)3: High, (67-100 percent confidence)Bits 11-12: Cirrus Confidence 0: Not Determined / Condition does not exist.1: Low, (0-33 percent confidence)2: Medium, (34-66 percent confidence)3: High, (67-100 percent confidence) |
- Bit 0: Designated Fill
- 0: No
- 1: Yes
- Bit 1: Terrain Occlusion
- 0: No
- 1: Yes
- Bits 2-3: Radiometric Saturation
- 0: No bands contain saturation
- 1: 1-2 bands contain saturation
- 2: 3-4 bands contain saturation
- 3: 5 or more bands contain saturation
- Bit 4: Cloud
- 0: No
- 1: Yes
- Bits 5-6: Cloud Confidence
- 0: Not Determined / Condition does not exist.
- 1: Low, (0-33 percent confidence)
- 2: Medium, (34-66 percent confidence)
- 3: High, (67-100 percent confidence)
- Bits 7-8: Cloud Shadow Confidence
- 0: Not Determined / Condition does not exist.
- 1: Low, (0-33 percent confidence)
- 2: Medium, (34-66 percent confidence)
- 3: High, (67-100 percent confidence)
- Bits 9-10: Snow / Ice Confidence
- 0: Not Determined / Condition does not exist.
- 1: Low, (0-33 percent confidence)
- 2: Medium, (34-66 percent confidence)
- 3: High, (67-100 percent confidence)
- Bits 11-12: Cirrus Confidence
- 0: Not Determined / Condition does not exist.
- 1: Low, (0-33 percent confidence)
- 2: Medium, (34-66 percent confidence)
- 3: High, (67-100 percent confidence)
代码:
代码语言:javascript复制/**
* @File : PIELandsat8_c2_TOA
* @Time : 2022/5/19
* @Author : piesat
* @Version : 1.0
* @Contact : 400-890-0662
* @License : (C)Copyright 航天宏图信息技术股份有限公司
* @Desc : 加载Landsat 8 collection2 TOA影像
*/
// 加载Landsat 8 TOA影像
var landsat8 = pie.ImageCollection("LC08/02/T1")
.filterDate("2022-01-01","2022-06-01")
.filter(pie.Filter.lte('cloud_cover',30))
.first()
.select(["B2","B3","B4"])
.multiply(0.0001)
print(landsat8)
Map.addLayer(landsat8,{min:0.05,max:0.3,bands:["B4","B3","B2"]},"Landsat8-TOA");
Map.centerObject(landsat8,7);
属性
landsat_product_id | string | 影像名称 |
---|---|---|
scene_id | string | 影像id |
correction | string | 产品级别 |
collection_number | string | 数据集编号 |
date | string | 影像日期 |
collection_category | string | 影像质量级别属性,如T2,T1等 |
cloud_cover | float | 云量覆盖百分比,-1表示未计算 |
cloud_cover_land | float | 陆地云量覆盖百分比,-1表示未计算 |
sun_azimuth | double | 太阳方位角 |
sun_elevation | double | 太阳高度角 |
off_nadir | double | 天底偏角 |
sensor_id | string | 传感器类型 |
wrs_path | int | 条带号 |
wrs_row | int | 行编号 |