Category Archives: work

基于知识推理的节水城市评估系统

学生应用clips做了一个简单的节水城市评估原型系统,初步演示了,

1. 知识推理引擎可以应用在水资源有关的管理和实践上。知识推理引擎尤其在涉及大量复杂知识规则的系统里,将十分有效;

2. clips与gis的集成,clips与其它应用程序的集成。

snap020snap021 

snap022

开发环境,

clips 6, Qt/win opensource, vc++ 2008 express, arcgis 9.2

一个多准则决策的图形程序

我们最近实现了一个多准则决策(Multi-Criteria Approach Decision Making)的一些简单算法,Qt 4实现,代码可以全部主流平台上编译。更多算法以插件的形式添加进来。

image
value function (analysis matrix -> evaluation matrix)

image
indicators简单加权实现及solution ranking

Difference between Radar precipitation data stage 2 and stage 4

Zhuotong Nan ([email protected])

Stage II

Be produced directly from the real-time gauge and WSR-88D radar data received at NCEP.

raingauges:

  • from ~1450 ASOS sites from near-real time METAR file
  • and from ~5500 HADS automated gauge reports via the GEOS data Collection Platform.

Radar:

  • Hourly real-time Digital Precipitation Arrays (DPAs) from 140 ConUS WSR-88D radar sites.

The primary input to the ETA/EDAS precipitation assimilation before 2003.

Stage IV

A mosaic of regional multi-sensor analysis produced by NWS River Forecast Centers (RFCs) and benefits from the RFCs’ manual quality control step

mosaicked from the regional multi-sensor 1h and 6h analyses produced by the 12 ConUS RFCs.

The primary input to the ETA/EDAS precipitation assimilation after 2003. Stage II is only used when Stage IV is unavailable.

In summary,

Since Stage IV benefits from manual QC at the local RFCs, it is generally better than Stage II, which has no manual QC. There are a number of other issues for your consideration:

1. Coverage period: Stage II began to be archived at NCAR on 1 May 1996. Stage IV did not began to be archived until 1 Jan 2002. (NOTE: we have data from 1997 on for OHIO river basin. I guess this statement is for entire continuous continental, rather than for an individual RFC. -Zhuotong)

2. Do you need hourly or 6-hourly analysis? For 6-hourlies, Stage IV is the one to use (if you don’t need the pre-2002 data). Stage IV hourlies have some coverage problem since we do not receive the local analyses from all the RFCs for all hours.

3. How soon do you need the analysis to be available? Stage II hourly analysis is made at 35 minutes after the top of the hour, then re-made twice at 6 hours and 18 hours later. Stage VI runs each hour at approximately 35 minutes past the top of the hour.

4. If I choose Stage II, which type should I use? We recommend the multi-sensor analysis with the exception of early spring – early Aug 2000, when the radar coverage was bad. You might want to use the gauge-only analysis for that time period.

Validation examples:

clip_image004 clip_image006

figure 1 24 hour precipitation accumulative amount on OCT 10, 2004, Stage II (left) and Stage IV (right).

clip_image008clip_image010

figure 2 Left: Stage II; Right: Stage VI. On Jun 28 2005. Here we can see the variance between them.

References:

1. http://www.emc.ncep.noaa.gov/mmb/ylin/pcpanl/refs/stage2-4.19hydro.pdf
2. http://www.emc.ncep.noaa.gov/mmb/ylin/pcpanl/QandA/
3. http://www.emc.ncep.noaa.gov/mmb/ylin/pcpverif/daily/

最近研究一下了HDF

因为需要对modis数据进行处理,研究了一下hdf和hdf eos两个类库
hdf是个好东西,不过有点太复杂,而且api尽管很强大,但工具还是相对不多,可以windows下使用的则更少
 

卸载网筝NK800 v2

南卓铜([email protected])

西部数据中心目前提供的网筝驱动程序v2(20060927)安装后不能正常卸载。我们已经向软件提供商反映此问题。这些提供了一个临时的解决方案。

1. 在开始菜单,找到“卸载网筝NK-800”,点击“属性”,copy目标里的内容。

image

2. 找到从westdc上下载来的驱动文件,如果是压缩包,请解压缩到一个目录,比如c:tempnk800目录下。这个路径以下有用。

3. 打开command窗口(开始->运行,键入cmd),将步骤1里目标内容,粘贴到命令行下(右键,粘贴),如下:

image

移动鼠标,更改

“C:Program FilesIn
stallShield Installation Information{9147E0F5-074A-4D73-B8EA-63FDE7C70330}Setu
p.exe” (注意,{}内的可能不一样)

为步骤2找到的位置(该目录下应该有原始的Setup.exe等文件)。我这里是,

“c:tempnk800Setup.exe”

现在完整命令如下所示,

C:WINDOWSsystem32RunDll32.exe C:PROGRA
~1COMMON~1INSTAL~1engine6INTEL3~1Ctor.dll,LaunchSetup “c:tempnk800Setu
p.exe”  -uninst  -f

4. 运行。按照出现的图形界面提示,完成卸载。

Group meeting有关multifractal云里雾里的

在Group meeting上给大家演示用multifractal+wavelet的方法做time-space downscaling。讲的稀里糊涂,听的也是云里雾里。其实在看的时候就有好多问题发现,但没有时间进一步去看相关文献。L老师提的问题又太过涉及公式本身。
不过这个paper proposed的方法估计本身也有问题,尽管结论说downscale还不错。但作者在此文发表后的后续工作又重新time和space分开来做downscaling了,估计也是意识到time和space结合在一起很难找到完美的方法。

ISO 19115 editor

一直在关注ISO 19115元数据有关的一些进展。
它的editor比较有名的包括:
– GeoNetwork OpenSource Desktop
– DISY Preludio
– ISO Metadata Editor (IME)
– CatMDEdit
– M3Cat
– MetaD
– ArcCatalog ISO Wizard
另外,OGC catalogue service也是比较有意思的一个东西。大家感兴趣可以从Google搜索以上产品。