NASA数据集——北美地区P 波段合成孔径雷达仪器的 1 (L1) 级极坐标雷达后向散射系数、多视角复合和极坐标校准和地理参照数据产品
NASA数据集——北美地区P 波段合成孔径雷达仪器的 1 (L1) 级极坐标雷达后向散射系数、多视角复合和极坐标校准和地理参照数据产品
ABoVE: L1 S-0 Polarimetric Data from UAVSAR P-band SAR, Alaska and Canada, 2017
简介
文件修订日期：2021-04-03
数据集版本: 1
摘要
本数据集提供了在美国阿拉斯加和加拿大西部 74 个研究地点采集的 UAVSAR P 波段合成孔径雷达仪器的 1 (L1) 级极坐标雷达后向散射系数（Sigma-0 或 S-0）、多视角复合、极坐标校准和地理参照数据产品。该雷达仪器是全偏振 P 波段（超高频）合成孔径雷达，工作频段为 420-440 兆赫。飞行活动于 2017 年 5 月至 8 月在美国国家航空航天局湾流-III 型飞机上定期进行。每组产品均由无人机合成孔径雷达 P 波段雷达仪器的一次数据采集（即获取）生成，一次数据采集相当于在一个地点上空飞行一条航线。每个站点需要 2 到 4 次数据采集，但有些站点只提供一次或六次数据采集。对 74 个站点共进行了 139 次数据采集。 无人机合成孔径雷达 P 波段雷达仪器最初是为空中微波次冠层和次表层观测站 （AirMOSS）活动开发的，用于测量根区土壤湿度。这些数据可用于次表层和次冠层成像应用，如监测土壤、森林和永久冻土的变化，以及探测地下结构和次表层变化。
139 种数据中每种数据的产品都在一个单独的目录中提供。每个目录包含 38 种不同类型的数据产品，共计 5,282 个数据文件。数据产品有两种分辨率，分别为 0.5 弧秒（约 15 米）和 3.0 弧秒（约 90 米），在每个文件名中均有标注。
UAVSAR P 波段合成孔径雷达扫描美国阿拉斯加和加拿大西部的研究地点，用于 2017 年 ABoVE 活动。
北极-北方脆弱性实验（ABoVE）是美国国家航空航天局（NASA）陆地生态计划的一项实地活动，于2016年至2021年期间在阿拉斯加和加拿大西部进行。ABoVE 的研究将基于实地的过程级研究与机载和卫星传感器获得的地理空间数据产品联系起来，为提高分析和建模能力奠定了基础，而分析和建模能力是了解和预测生态系统反应及社会影响所必需的。
空间分辨率：0.5 弧秒和 3.0 弧秒
时间覆盖范围2017 年 5 月至 2017 年 8 月的定期飞行。
时间分辨率：每日
研究区域：纬度和经度均以十进制度表示。
Sites | Westernmost Longitude | Easternmost Longitude | Northernmost Latitude | Southernmost Latitude |
|---|---|---|---|---|
Alaska and western Canada | -114.052479 | -104.183584 | 71.464621 | 52.077702 |
数据信息
139 个数据中的每一个都有 38 个数据产品（多种格式），共计 5 282 个数据文件。数据产品有两种分辨率，分别为 0.5 弧秒（约 15 米）和 3.0 弧秒（约 90 米）。
扩展名为 .ann、.h5、hgt、.inc、.jpg、.kmz、.png 和 .slope 的文件命名为 ssssss_LLLLL_FFFFF_CCC_YYMMDD_PL090fffww_gg_CX_vv.ext （例如，tukhwy_01812_17057_014_170606_PL09043020_05_CX_01.ann）。
扩展名为 .grd 和 .mlc 的文件命名为 ssssss_LLLLL_FFFFF_CCC_YYMMDD_PL090fffww_ggpppp_CX_vv.ext （例如，tukhwy_01812_17057_014_170606_PL09043020_30HVV_CX_01.mlc）。
Element | Short Name | Example Value | Description |
|---|---|---|---|
ssssss | Site name | padelE | 6-character alphanumeric identifier assigned to each ABoVE flight line For sites with a single flight line, the 6 characters identify the site, whereas sites with multiple flight lines have 5 characters to identify the flight line followed by a letter (N, S, E, W, A, B, C, D) that identifies the flight line within the site |
LLLLL | Flight line ID | 00026 | 5-character flight line identifier, where the first 3 characters are the aircraft heading in integer degrees (range 000–359) and the last 2 characters are from an alphanumeric counter to ensure uniqueness |
FFFFF | Flight ID | 17051 | 5-digit flight identifier, where the first 2 digits are the last 2 digits of the flight year and the following 3 digits are from a numeric counter to ensure uniqueness |
CCC | Data take counter | 009 | 3-digit data take counter for the flight (range 0-9); a first digit of 0 indicates that the data take was collected using automatic mode, while a first digit of 1 indicates that it was collected using manual mode; usually, the data take counter starts at 000 for the first science data take of a flight and is incremented by 1 for each successive science data take; since the radar system may reinitialize the counter if a system reset occurs during flight, the data take counter may not be unique for a flight |
YYMMDD | Flight date | 170522 | UTC date at the start of the data take, where YY is the last two digits of the flight year, MM is the month of the year, and DD is the day of the month |
PL09043020 | Radar mode | 10-character alphanumeric identifier; see Table 3 for the naming convention | |
gg | Spatial resolution | 30 | 2-digit grid spacing in integer units of 0.1 arcseconds, where 05 represents 0.5" and 30 represents 3.0" |
pppp | Cross product abbreviation | HHHV | Formed from the subscripts of the two factors of the cross products as read from left to right (e.g., the abbreviation for the cross product SHHS'*HV is HHHV), where values are HHHH, HHHV, HHVV, HVHV, HVVV, and VVVV |
CX | Crosstalk removal status | CX | 2-character crosstalk removal status; the value is CX when crosstalk has been removed and XX when crosstalk has not been removed; ABoVE L1-S-0 data products use the value CX only |
vv | Version number | 01 | 2-digit product version number starting at 01; the version number is incremented by 1 when a product is redelivered |
ext | Extension | ann | File format extension |
Table 2. Six-letter abbreviations for study sites. Some sites contain subsites (identified in parentheses) and multiple data takes.
Site Abbreviation | Site Name |
|---|---|
aklavi | Aklavik Ice Road, NT, Canada |
ambler | Ambler permafrost borehole site, AK, USA |
anakt (E,W) | Anaktuvuk Pass, AK, USA |
atqasu | Atqasuk permafrost borehole site, AK, USA |
barrow | Barrow permafrost borehole site, AK, USA |
behcho | Behchoko, NT, Canada |
berms (A,B,C,D) | Boreal Ecosystem Research and Monitoring Sites (BERMS), SK, Canada |
chevak | Chevak, AK, USA |
coldfo | Coldfoot permafrost borehole site, AK, USA |
counci | NGEE Arctic site, Council, AK, USA |
daring | Daring Lake, NT, Canada |
deltj (A,B,C) | Delta Junction, AK, USA |
dhorse | Deadhorse permafrost borehole site, AK, USA |
djNEON | Delta Junction NEON site, AK, USA |
faberl | Faber Lake, NT, Canada |
fliard | Fort Liard, NT, Canada |
fsmit (N,S) | Fort Smith, NT, Canada |
ftmacm | Fort McMurray, AB, Canada |
ftres (N,S) | Fort Resolution, NT, Canada |
ftyuko | Fort Yukon, AK, USA |
gdhope | Fort Good Hope, NT, Canada |
huslia | Huslia permafrost borehole site, AK, USA |
inigok | Circumpolar Active Layer Monitoring (CALM) site, Inigok, AK, USA |
innoko | Innoko River, AK, USA |
ivotuk | Ivotuk permafrost borehole site, AK, USA |
kakis (A,B) | Kakisa Lake, NT, Canada |
katma (A,B,C) | Katmai National Park and Preserve, AK, USA |
kluan (A,B) | Kluane National Park and Reserve, YT, Canada |
kougar | Kougarok permafrost borehole site, AK, USA |
koyukk | Koyuk permafrost borehole site, AK, USA |
lclark | Lake Clark National Park and Preserve, AK, USA |
lloydE | East of Lloydminster, SK, Canada (also AirSWOT study site) |
lloydW | West of Lloydminster, AB, Canada (also AirSWOT study site) |
mcpher | Fort McPherson, NT, Canada |
noatak | Noatak National Preserve, AK, USA |
nwells | Norman Wells, NT, Canada |
oldcr (A,B) | Old Crow, YT, Canada |
padel (E,W) | Peace–Athabasca Delta, AB, Canada |
poorma | Poorman, AK, USA |
provid | Fort Providence, NT, Canada |
redber | Redberry, SK, Canada (also AirSWOT study site) |
saska (N,S) | Saskatoon, SK, Canada (also AirSWOT study site) |
scoaoi | Sambaa K’e (formerly Trout Lake), NT, Canada |
scotty | Scotty Creek, NT, Canada |
snagyk | Snag, YT, Canada |
snarer | Snare River, NT, Canada |
sriver | Stony River, AK, USA |
teller | Teller NGEE Arctic site, AK, USA |
toolik | Toolik Lake and Field Station, AK, USA |
tukhwy | Inuvik–Tuktoyaktuk Highway, NT, Canada |
watson | Watson Lake, YT, Canada |
wolfcr | Wolf Creek Trail, YT, Canada |
wrigl (N,S) | Wrigley, NT, Canada |
yellow | Yellowknife, NT, Canada |
yflat (E,W) | Yukon Flats National Wildlife Refuge, AK, USA |
ykdel (A,B) | Yukon Delta National Wildlife Refuge, AK, USA |
Table 3. Radar mode naming convention elements.
Element | Short Name | Description |
|---|---|---|
P | Radar band | Radar band; 1-character fixed value P for these products |
L | Radar look direction | Left-looking radar relative to the direction of flight; 1-character fixed value L for these products |
090 | Squint angle | Squint angle in integer degrees; 3-digit fixed value 090 for these products |
430 | Chirp frequency | Chirp center frequency in MHz; 3-digit fixed value 430 for these products |
20 | Chirp bandwidth | Chirp bandwidth in MHz; 2-digit fixed value of 20 for these products; the value has been rounded for use in the filenames, while the true value is provided in the Bandwidth field of the associated ANN files |
Table 4. Data product file extensions. See Section 5 for additional information.
Element | Number of Files per Data Take | Description |
|---|---|---|
ann | 2 files: 1 for the 0.5 arcsecond grid spacing and 1 for 3.0 arcsecond | Annotation (text) files containing metadata including filenames, file dimensions, grid coordinates, and radar processing parameters |
grd | 12 files: 6 for the 0.5 arcsecond grid spacing and 6 for 3.0 arcsecond | Georeferenced/gridded data (GRD) generated by projecting (slant-range) single-look complex data to ground range using the backward projection method |
h5 | 2 files: 1 for the 0.5 arcsecond grid spacing and 1 for 3.0 arcsecond | Hierarchical Data Format Version 5 (HDF5) files containing copies of the DEM, GRD, INC, MLC, and SLOPE |
hgt | 2 files: 1 for the 0.5 arcsecond grid spacing and 1 for 3.0 arcsecond | Digital elevation map (DEM) used during processing; co-registered to the GRD |
inc | 2 files: 1 for the 0.5 arcsecond grid spacing and 1 for 3.0 arcsecond | Local incidence angle (INC); co-registered to the GRD |
jpg | 2 files: 1 for the 0.5 arcsecond grid spacing and 1 for 3.0 arcsecond | Browse thumbnails in JPEG media format produced from the PNG |
kmz | 2 files: 1 for the 0.5 arcsecond grid spacing and 1 for 3.0 arcsecond | Compressed Keyhole Markup Language (KMZ) files containing the GRD rendered as low-resolution color images for display in Google Earth |
mlc | 12 files: 6 for the 0.5 arcsecond grid spacing and 6 for 3.0 arcsecond | Multi-looked complex (MLC) cross products |
png | 2 files: 1 for the 0.5 arcsecond grid spacing and 1 for 3.0 arcsecond | Portable Network Graphics (PNG) images of the KMZ |
slope | 2 files: 1 for the 0.5 arcsecond grid spacing and 1 for 3.0 arcsecond | Terrain slope (SLOPE) derived from the DEM in the east and north directions |
雷达反向散射数据已利用部署在加利福尼亚州罗萨蒙德干湖的 2.4 米和 4.8 米三面角反射器以及噪声二极管内置测试（BIT）（Chapin 等人，2015 年）的接收器数据进行了辐射校准。2017 年，噪声二极管 BIT 数据被用于改进天线模式。使用噪声二极管 BIT 数据后，4.8 米角反射器残差（观测-预测雷达截面）的标准偏差从 0.867 dB 降至 0.543 dB（横积的 HH 因子），从 0.668 dB 降至 0.521 dB（横积的 VV 因子）。对于 2.4 米角反射镜残差，HH 和 VV 的标准偏差分别从 0.861 dB 和 0.564 dB 降至 0.564 dB 和 0.599 dB。
对于 2017 年开始获取的 P 波段数据，在每次数据采集之前和/或之后立即获取的噪声二极管 BIT 数据用于在处理过程中对数据进行辐射校正。在相位校准之前对数据进行了串扰消除（Fore 等人，2015 年）。自适应射频干扰消除根据需要应用于每次数据采集（Harcke 和 Le，2014 年）。其应用已记录在每个产品的相关 ANN 文件中。在相关 ANN 文件的注释字段中注明了该过程无法去除的 RFI。
代码
!pip install leafmap
!pip install pandas
!pip install folium
!pip install matplotlib
!pip install mapclassify
import pandas as pd
import leafmap
url = "https://github.com/opengeos/NASA-Earth-Data/raw/main/nasa_earth_data.tsv"
df = pd.read_csv(url, sep="\t")
df
leafmap.nasa_data_login()
results, gdf = leafmap.nasa_data_search(
short_name="ABoVE_L1_P_SAR_1800",
cloud_hosted=True,
bounding_box=(-166.61, 52.08, -104.18, 71.46),
temporal=("2017-05-22", "2017-08-18"),
count=-1, # use -1 to return all datasets
return_gdf=True,
)
gdf.explore()
#leafmap.nasa_data_download(results[:5], out_dir="data")引用
Shimada, J.G., Y. Lou, S. Hensley, B.P. Hawkins, L. Harcke, D.M. Lagoy, T.R. Michel, R.J. Muellerschoen, S. Flores, N. Pinto, C. Rains, W.W. Tung, and Y. Zheng. 2021. ABoVE: L1 S-0 Polarimetric Data from UAVSAR P-band SAR, Alaska and Canada, 2017. ORNL DAAC, Oak Ridge, Tennessee, USA. ABoVE: L1 S-0 Polarimetric Data from UAVSAR P-band SAR, Alaska and Canada, 2017, https://doi.org/10.3334/ORNLDAAC/1800