amsr.2 / AMSRE

介绍

The Advanced Microwave Scanning Radiometer has operated on three satellites:

  • amsr.-2 on JAXA's GCOM-W1 spacecraft, launched May 18, 2012. This instrument is currently operating.
  • AMSR-E.on NASA's EOS Aqua spacecraft, launched May 4, 2002. The instrument stopped rotating Oct 4, 2011.
  • AMSR在Jaxa的Adeos-II宇宙飞船上推出,2002年12月14日推出。卫星太阳能电池板于2003年10月25日失败。

In this web site, we use the term AMSR-J to represent the AMSR radiometer flown by JAXA on ADEOS-II. This distinguishes it from the AMSR-E on the NASA Aqua satellite and the AMSR-2 instrument on the GCOM-W1 satellite.

我们已经处理了所有这些仪器的数据,以提供典型的RSS微波辐射计海洋测量产品套件:海面温度(SST),表面风速(低频率),大气水蒸气,云液体水和雨率。AMSR-2和AMSR-E海洋产品是用Version-7进行创建的,使它们与Windsat和SSM / I和SSMI一致。AMSR-J目前保留为版本-5数据。AMSR2数据于2017年9月重新加工到版本-8。小的变化包括11 V低噪声放大器中的非线性的校正,当它变得非常热并且使用正确的占地面积,从版本-7.1减少了雨率的正确占地面积。

A key feature of these AMSR instruments is the ability to see through clouds, thereby providing an uninterrupted view of ocean measurements. There are differences between the three instruments as outlined in the table below.

amsr.-2 AMSR-E. AMSR-J.
Satellite Platform GCOM-W1 AQUA ADEOS-II
Altitude 700 km 705 km 802.9公里.
Equator Crossing Time
(当地时区)
1:30 PM Ascending
1:30 AM Descending
1:30 PM Ascending
1:30 AM Descending
10:30 PM Ascending
10:30 AM Descending
Antenna Size 2 m 1.6 m 2 m
Swath Width 1450 km 1450 km 1600 km

The wider swath of AMSR-J provides greater coverage, but comes at the expense of accuracy near the swath edges. Here is a worst case example:

图1. AMSR-J SWATH边缘伪像在SST中只有明显,并且在使使徒位置最不稳定并且最不准确地知道时,在使命中最突出。

Instrument Description

The AMSR instruments are dual-polarized, conical scanning, passive microwave radiometers. Each is placed in a near-polar orbit which allows for up to twice daily sampling of a given Earth location. The eight instrument channels are summarized in the following tables.

We use an on-orbit calibration method developed by RSS to convert counts to brightness temperatures. Calibration methodology and preliminary validation results are described in the following conference paper:"On-Orbit Calibration of AMSR-E and the Retrieval of Ocean Products"

amsr.-2on GCOM-W1

Band [GHz] 极化

Spatial Resolution
(3-dB footprint size)
(km x km]

6.93 V,H 62 x 35
7.3 V,H 62 x 35
10.65 V,H 42 x 24
18.7 V,H 22 x 14
23.8 V,H 19 x 11
36.5 V,H 12 x 7
89.0 V,H 5 x 3

AMSR-E.on Aqua

Band [GHz] 极化

Spatial Resolution
(3-dB footprint size)
(km x km]

6.93 V,H 75 x 43
10.65 V,H 51 x 29
18.7 V,H 27 x 16
23.8 V 32 x 18
36.5 V,H 14 x 8.
89.0 V,H 6 x 4

amsr.on ADEOS-II

Band [GHz]

极化

Spatial Resolution
(3-dB footprint size)
(km x km]

6.93 V,H 70 x 40
10.65 V,H 46 x 27
18.7 V,H 25 x 14
23.8 V,H 29 x 17
36.5 V,H 14 x 8.
50.3 V 10 x 6
52.8 V 10 x 6
89.0 V,H 6 x 3

RSS AMSR Data Products

当前版本的RSS辐射传输模型和辐射计处理代码是版本-7。AMSR-2 V7数据首先是2014年1月的v7.1,并在2014年7月再处理到V7.2,AMSR-E V7数据于2011年10月发布。我们建议仅使用最新数据。

We produce Daily binary data files and Time-Averaged (3-day, weekly and monthly) data files for all instruments. The daily files consist of ocean measurements mapped to a regular grid complete with data gaps between orbits. Two maps exist for each parameter, one of ascending orbit segments (local daytime passes) and the other of descending orbit segments (local nighttime passes). Data on each of the segment maps are overwritten at both the high latitudes where successive orbits cross and at the "seam" or region where the last orbit of the day overlaps the first orbit of the day. Daily data files contain time maps consisting of the UTC observation time for each set of passes (ascending and descending). Time-Averaged data files do not contain any time information.

Gridded data are organized according to observation date. All dates and times are Coordinated Universal Time (UTC), also known as Greenwich Mean Time (GMT), Zulu Time (Z), Universal Time (UT), and World Time. Data products include daily and time averaged geophysical data as follows:

Daily orbital data mapped to 0.25 degree grid divided into 2 maps based on ascending and descending passes early data may be overwritten by later data at high latitudes and daily "seam"
为期3天 average of 3 days ending on and including file date
Weekly average of 7 days ending on and including the Saturday file date
Monthly average of all data within the calendar month

Each binary data file available from our ftp site consists of fourteen (daily) or six (averaged) 0.25 x 0.25 degree grid (1440,720) byte maps. For daily files, seven daytime, ascending maps in the following order, Time (UTC), Sea Surface Temperature (SST), 10 meter Surface Wind Speed (WSPD-LF), 10 meter Surface Wind Speed (WSPD-MF), Atmospheric Water Vapor (VAPOR), Cloud Liquid Water (CLOUD), and Rain Rate (RAIN), are followed by seven nighttime maps in the same order. Time-Averaged files contain just the geophysical layers in the same order [SST, WSPD-LF, WSPD-MF,VAPOR, CLOUD, RAIN].

Acronym 产品
Name
产品
Description
Scale Offset Valid Data Range Reason for No Data
TIME Time

自午夜以来的总格总格
Fractional hour of day GMT

6.0
0.1

0.
0.

0 to 1440
0.0到24.0.

no data
SST Sea surface temperature Temperature of top layer (skin) of
water ~1 mm thick
0.15 -3.0 -3 to 34.5 deg 高风(<20米/秒),太阳闪光,雨,RFI,海冰或土地附近(〜75公里)
WSPD_LF 10-m wind speed 风speed using channels:
10.7, 18.7, 23.8, and 36.5 GHz
0.2 0. 0.to 50.0 m/s sun glint, rain, RFI, near sea ice or land (~50 km)
WSPD_MF 10-m wind speed 风speed using channels:
18.7, 23.8, and 36.5 GHz
0.2 0. 0.to 50.0 m/s sun glint, rain RFI, near sea ice or land (~50 km)
Columnar atmospheric water vapor Total gaseous water contained in a
垂直柱的大气
0.3 0.

0.to 75.0 mm
1 gm/cm2= 10mm

heavy rain or near land (~25 km)
CLOUD* 柱状云液体水 Total cloud liquid water contained in a
垂直柱的大气
0.01 -0.05 -0.05to 2.45 mm near land (~25 km)
雨率 Rate of liquid water precipitation 0.1 0. 0.25.0毫米/小时 near land (~25 km)

*注意:版本-5 AMSR-J数据没有此表中显示的云偏移量。对于版本-5,有效的云范围为0至2.5 mm。这些文件仅包含1个风(LF),总共6而不是7个数据层。

The data values between 0 and 250 need to be scaled to obtain meaningful geophysical data. To scale the data, multiply by the scale factors listed in the table above.

我们生产两种标准无雨辐射计风产品:WSPD_LF(低频)和WSPD_MF(中频)。首先,使用10.65GHz的频道,包括37 GHz(见上文的表格)而创建WSPD_LF,并且与版本-5 AMSR-E数据文件或TMI的第一个风中提供的唯一风力文件。第二个WSPD_MF使用18.7 GHz的频率通道,包括37 GHz,最类似于SSM / I和SSMIS风。

Each wind product has distinct advantages. The WSPD_LF is less affected by the atmosphere and rain, but is affected by 10.65 GHz RFI and sun glitter effects. The WSPD_MF has a higher effective spatial resolution, is less affected by ice and land contamination, and is only slightly affected by sun glitter effects and RFI. The WSPD_MF are a little noisier than the WSPD_LF.

每日,3天和每月地图存储在适当的年份和月份子目录中。每周数据文件存储在/周目录中。

The file names have the following naming conventions:

Time Directory Path 文件名
Daily [年] / [月] / fs_yyyymmddvv.v.gz.
为期3天 [年] / [月] / fs_yyyymmddvV.v_d3d.gz
Weekly 周/ fs_yyyymmddvv.v.gz.
Monthly [年] / [月] / fs_yyyymmvV.v.gz

Where "sat", "yyyy", "mm", "dd", and "V.v(Note minor version is ommited if 0)" stand for:

fs 文件说明符 f34

yyyy

一年 2014, 2015 etc.
毫米 month 01 (Jan), 02 (Feb), etc.
dd 01, 02, etc.
vv version V.v

1440列和720行地图的第一电池的中心处于0.125 e经度和-89.875纬度。第二个电池的中心是0.375 e经度,-89.875纬度。数据值均为0到255.已保留特定值:

0 to 250 = valid geophysical data
251 = 由于雨,由于雨而缺少水速或缺少水蒸气
252 = sea ice
253 = observations exist, but are bad (not used in composite maps)
254 = no observations
255 = land mass

缺失数据

There are gaps within these data. Missing data generally affect Daily and 3-Day products, but can also reduce the number of observations in Weekly and Monthly averages.

When browsing imagery, the navigation may skip dates with no data, or you may see a blank map stating that no data are available for that time.

Binary data files for dates with completely missing data are not produced; they will be absent from our FTP server.

Data gaps are generally due to missing data upstream from our processing facility, such as the instrument being turned off. Occasionally, there are delays in obtaining and/or processing recently recorded data; beyond several weeks, it is unlikely that missing data will become available.

Dates for which AMSR-E data are completely missing include:

date range # 天
2002.06.28 1
2002.07.30 - 2002.08.07 9
2002.09.13——2002.09.19 7
2003.10.30 - 2003.11.05 7
2004.11.19 1
2006.11.18 1
2007.11.28 1
2008 none 0
2009 none 0
2010.02.03 - 2010.02.04 2
2011 instrument stopped Oct 4th 2011 88

Dates for which AMSR2 data are completely missing include:

date range # 天
2013.05.11 - 2013.05.13 3

Browse Images

Each daily, 3-day, weekly and monthly browse image map displays one geophysical parameter: Sea Surface Temperature (SST), 10 meter Surface Wind Speed (WSPD-LF), 10 meter Surface Wind Speed (WSPD-MF), Columnar Water Vapor (VAPOR), Cloud Liquid Water (CLOUD), or Rain Rate (RAIN). The daily maps display the daytime or nighttime satellite passes separately. The date of the data displayed is the UTC date when the data were collected. The scale for each map is located next to the map for reference. Though the valid data range (minimum to maximum) is given in the geophysical table above, the scale bars in the browse images are set to visually enhance the data and may vary.

There are many gaps within the AMSR-J data set. Please use the browse imagery or FTP site to determine specific availability.

Read Routines

Binary file read routines and verification files are available on our ftp server in the amsre/support directory. Routines are written in IDL, Matlab, Fortran and Python.

验证

验证of AMSR2 products like all microwave ocean products from RSS undergo continual validation. We post important findings here.

雨率s

amsr.2 rain rates are higher in the tropics than other RSS satellite products. The figure below shows that the difference between AMSR2 and SSMIS (F17) in the tropics is +9.9%. The difference between AMSR2 rain rates and the 10-minute rain rates from the tropical buoy array is +8.3% using a 3-hour collocation radius. In the mid-latitudes, AMSR2 rain rates are lower than SSMIS, leading to a zero overall global difference. The source of this latitude-dependent difference in AMSR2 rain is currently under investigation as part of our “Complete Uncertainty Characterization of the DISCOVER Earth System Data Records” project.

rain rate comparison figure

相关数据

amsr.ocean products are also available from other sources. AMSR-E data are produced at the NASA Snow and Ice Data Center (NSIDC) using RSS processing algorithms. VisitNSIDCfor data description and data access.

AMSR-J.and AMSR2 data are also available from the Japanese Space Agency (JAXA).

amsr.2 data are available from the JPL PO.DAAC in theGhrsstL2p and L3u formats.

References

Hilburn,K. A.和F. J.Ventz,(2008),互补的微波海洋检索算法(UMORA)的Intercalibrated被动微波雨水, Journal of Climatology and Applied Meteorology, 47, 778-794.

Meissner,T.和F. J.Ventz,(2012),The emissivity of the ocean surface between 6 - 90 GHz over a large range of wind speeds and Earth incidence angles, IEEE TGRS, 50(8), 3004-3026.

Wentz, F. J., C. L. Gentemann and P. D. Ashcroft, (2003),On-orbit calibration of AMSR-E and the retrieval of ocean products, paper presented at 83rd AMS Annual Meeting, Long Beach, CA.

Wentz,F.J.,C.L.Getemann和K. A. Hilburn,(2005),Three years of ocean products from AMSR-E: Evaluation and applications, paper presented at Proceedings of the 2005 IEEE International Geoscience and Remote Sensing Symposium,Seoul, Korea.

Wentz f·j·t·迈斯纳,(2000),AMSR Ocean Algorithm,版本2,报告编号121599A-1,66 pp。,遥感系统,圣罗莎,加利福尼万博体育app网页注册亚州。

Wentz f·j·t·迈斯纳,(2007),AMSR-E.Ocean Algorithms; Supplement 1,报告编号051707,6 pp。,遥感系统,圣罗莎,加利福尼万博体育app网页注册亚州。

Acknowledgements

amsr.data are produced by Remote Sensing Systems and the NASA AMSR-E Science Team. We are grateful to JAXA and JPL for providing us with AMSR-2, AMSR and AMSR-E instrument data.

如何引用这些数据

继续生产此数据集需要支持NASA。我们需要您在出版物中使用时务必引用这些数据,以便我们可以展示向科学界的数据的价值。manbext万博官网请在纸质的确认部分中包含以下声明:

"AMSR data are produced by Remote Sensing Systems and were sponsored by the NASA AMSR-E Science Team and the NASA Earth Science MEaSUREs Program. Data are available atwww.dj-hx.com。"

下面给出了用于出版物的官方数据引文。manbext万博官网在括号中插入适当的信息。

对于AMSR2:Wentz,F.J.,T. Meissner,C.Getemann,K.A。Hilburn,J. Scott,2014:遥感系万博体育app网页注册统GCOM-W1 AMSR2 [指示您是否使用每日,3天,每周或每月]环境套件在0.25°Grid版本V.V中,[表示子集,如果使用了]。万博体育app网页注册遥感系统,圣罗莎,加利福尼亚州。在线提供www.dj-hx.com/missions/amsr。(Accessed dd mmm yyyy].

For AMSR-E: Wentz, F.J., T. Meissner, C. Gentemann, M.Brewer, 2014: Remote Sensing Systems AQUA AMSR-E [indicate whether you used Daily, 3-Day, Weekly, or Monthly] Environmental Suite on 0.25 deg grid, Version V.v [indicate subset if used]. Remote Sensing Systems, Santa Rosa, CA. Available online atwww.dj-hx.com/missions/amsr。(Accessed dd mmm yyyy].

For AMSR on ADEOS-II (we call it AMSR-J): Wentz, F.J., L. Ricciardulli, 2007: Remote Sensing Systems MIDORI AMSR [indicate whether you used Daily, 3-Day, Weekly, or Monthly] Environmental Suite on 0.25 deg grid, Version 5 [indicate subset if used]. Remote Sensing Systems, Santa Rosa, CA. Available online atwww.dj-hx.com/missions/amsr。(Accessed dd mmm yyyy].