2009-02-05T10:45:37Z

Wbuytaert:

[[Category:Projects]]
[[Category:Remote Sensing]]

== Overview of remote sensing data that may be useful for hydrological analysis ==

=== Spectrometer ===

{|border = "1"
!Institute!!Satellite!!Sensor!!channels!!launched!!resolution!!Notes
|-
|ESA ||[http://en.wikipedia.org/wiki/Envisat ENVISAT] ||MERIS ||15||March 2002||260x290m||Visible and Near Infrared spectrum (390 to 1040 nm), cloud cover, water bodies, frequency 3 days (higher at the poles)
|-
|NASA
|TIROS-N
|AVHRR
|4
| 
|1.09x1.09km
| rowspan="6" valign="top"| http://www.nsof.class.noaa.gov. <br/> Can be used for cloud cover (Bendix et al.), surface temperature (ref), delineation of water bodies (Zhou et al., 2000)
|-
|NOAA||NOAA-7||AVHRR||5|| ||
|-
|NOAA||NOAA-15||AVHRR||6||May 1998||
|-
|NOAA||NOAA-16||AVHRR||6||Sep 2000||
|-
|NOAA||NOAA-17||AVHRR||6||Jun 2002||
|-
|NOAA||NOAA-18||AVHRR||6||May 2005||
|-
|Eumetsat||METOP||AVHRR||?||||||cloud cover, surface temperature
|-
|NASA||EOS AQUA ||AMSR-E ||||||||??
|-
|ESA||MSG-1 & 2 (Meteosat-8 & 9)||SEVIRI||12||2002||||Spinning Enhanced Visible and Infrared Imager. [[http://www.eumetsat.int/Home/Main/Access_to_Data/Meteosat_Image_Services/SP_1123237865326 Africa and Europe]] @ 15 minutes. 8 channels can be used for monitoring the earth surface. Channel 12 is a high resolution visible (hrv) channel. Resolution: 3 km at the sub-satellite point (5 – 6 km over Europe). Channel 12 has a resolution of 1 km at the sub-satellite point (1.5 – 2 km over Europe). Can be used for precipitation (see e.g. Thiess et al. doi:10.1029/2008JD010464)
|-
|NASA||TRMM||??||||||25x25km (0.25°)|| rainfall
|-
|NASA||TERRA||ASTER||[http://en.wikipedia.org/wiki/Advanced_Spaceborne_Thermal_Emission_and_Reflection_Radiometer 15]||1999||15-90m||temperature, reflectance, elevation, land use. On demand; some images exist for the Andes
|-
|NASA||TERRA/AQUA||[http://en.wikipedia.org/wiki/MODIS MODIS]||36||1999/2002||see notes||http://www.landcover.org, spatial resolution: 250 m (bands 1-2) 500 m (bands 3-7) 1000 m (bands 8-36), temporal resolution 1 to 2 days, visible and near infrared (400 to 14400 nm)
|}

=== radar ===

{|border = "1"
!Institute!!Satellite!!Sensor!!launched!!resolution!!Notes
|-
|ESA ||[http://en.wikipedia.org/wiki/Envisat ENVISAT]||ASAR ||March 2002||30m||APG HH and HV -> delineation of water bodies
|-
|ESA ||[http://en.wikipedia.org/wiki/Envisat ENVISAT]||Altimeter||March 2002||400m||altitude (only 1 dimension)
|-
|MDA||[http://en.wikipedia.org/wiki/RADARSAT-1 RADARSAT-1]||ASAR||November 1995||10m||commercial (Canadian private company)
|-
|MDA||[http://en.wikipedia.org/wiki/RADARSAT-2 RADARSAT-2]||ASAR||December 2007||3m||commercial (Canadian private company)
|-
|ASI||[http://en.wikipedia.org/wiki/COSMO-SkyMed COSMO-SkyMed]||SAR||June 2007|| || Constellation of 4 satellites
|}

=== other ===

One that has not gone up yet: [http://bprc.osu.edu/water/index.php SWOT]

== Data aquisition ==

=== ESA ===

ESA is a very big engine and it is tricky to find what you are actually looking for or what you need but there is lots:

The following link is a shortcut to ESA's 'Resources' page that includes upcoming workshops, the ESA library, data samples and archives, and probably most useful for anyone working with ESA data, there are ESA-tailored software tools that run free-of-charge on Windows, linux and also MacOS (although mac versions are usually appearing a bit later than the other two!): http://earth.esa.int/resources/
P.S. I attended an ESA Land Training course in Lisbon in September 2007 on Flooding/Soil moisture and Forests and have lots of lecture notes on ASAR, ALOS and how to use these data with the BEST, BEAM and POLSARPRO packages (I have actually worked with an ALOS quadpol for tree height and soil moisture retrieval: amazing data!).
If you want any of these notes or some help, just email me (guy.schumann@bristol.ac.uk) and I'll try to help!

There is a useful tool from the ESA website to search for available images (does ENVISAT and others):

http://eoli.esa.int/

To access online (last 7-10 days) data and submit CAT-1 (free data) proposals for projects:

http://earth.esa.int/dataproducts/accessingeodata/

To answer third party mission (from non-ESA satellites) calls: http://eopi.esa.int/esa/esa?type=10&cmd=aolist, and go to the 'TPM' link to the left of the page,

and AO (Announcement of Opportunities) calls: http://eopi.esa.int/esa/esa?type=10&cmd=aolist

=== ESA conferences and workshops ===

Anyone interested in this year's (2008) ESA summer school in August (4-14) at the ESRIN centre in Italy? Topic: Data assimilation, monitoring and modelling the Earth System. Have a look at: http://envisat.esa.int/envschool/

== Detailed info on satellites ==

=== meteosat ===

The channels of SEVERI on board meteosat-8 (spectral band / μm)

(from http://las.physik.uni-oldenburg.de/eProceedings/vol05_1/05_1_de-ruyter1.pdf)

{|border=1
!Channel!!min!!max!!description
|-
| 1 || 0.635 || 0.56 || 0.71 visual
|-
| 2 || 0.81 || 0.74 || 0.88 visual
|-
| 3 || 1.64 || 1.50 || 1.78 near infrared
|-
| 4 || 3.90 || 3.48 || 4.36 infrared
|-
| 5 || 6.25 || 5.35 || 7.15 infrared (water vapour absorption)
|-
| 6 || 7.35 || 6.85 || 7.85 infrared (water vapour absorption)
|-
| 7 || 8.70 || 8.30 || 9.1 infrared
|-
| 8 || 9.66 || 9.38 || 9.94 infrared (ozone absorption)
|-
| 9 || 10.80 || 9.80 || 11.80 infrared
|-
| 10 || 12.00 || 11.00 || 13.00 infrared
|-
| 11 || 13.40 || 12.40 || 14.40 infrared (CO2 absorption)
|-
| 12 || 0.75 || 0.60 || 0.90 high resolution visual broadband (hrv)
|}

== Processing ==

=== Envisat altimeter ===

Some information that may make life easier when dealing with ESA's altimeter N1 files:

* ESA's [http://earth.esa.int/brat/html/data/toolbox_en.html Basic Radar Altimeter Toolbox] provides a set of tools and an interface for extracting data from the original N1 files. The interface is broken on recent linux versions due to obsolete dependencies but the command line tools work.

* The XY extraction utility (BratCreateZFXY) does not seem capable of extracting the original data directly. It requires a predefined raster size and automatically interpolates before exporting.

* BratCreateYFX extracts the measurements in the original resolution. However it only includes one dimension so you have to add the other one manually as a dataset. Something like this in the parameter file:

# longitude
X=lon
X_NAME=X
X_TYPE=Longitude
X_UNIT=degrees_east
X_TITLE=X
# latitude
FIELD=lat
FIELD_NAME=Y
FIELD_TYPE=Data
FIELD_UNIT=count
FIELD_TITLE=Y
# data of interest follow
FIELD=alt_cog_ellip
FIELD_NAME=alt_cog_ellip
FIELD_TYPE=Data
FIELD_UNIT=mm
FIELD_TITLE=alt_cog_ellip

* Extracting many fields from many files is '''much''' easier using the command line tools and a batch script.

== downscaling techniques ==

=== statistical ===

singular vector decomposition

Bretherton CS, Smith C, Wallace JM. 1992. An intercomparison of methods for finding coupled patterns in climate data. Journal of Wilks DS. 1995. Statistical Methods in the Atmospheric Sciences. Climate 5: 541–560

=== dynamical ===

REW

2009-02-02T19:48:16Z

Wbuytaert:

[[Category:Projects]]
[[Category:Hydrology in R]]

== Introduction ==

This page collects information about the application of the Representative Elementary Watershed model.

== Versions ==

=== THREW ===

C version maintained by Fuqiang Tian (University of Illinois)

=== CREW ===

FORTRAN version maintained by Haksu Lee

== Installation ==

=== THREW ===

==== Macintosh / linux ====

An easy way to install on mac and linux is by creating first static libraries for the solver and then linking those in the application. The advantage of this is that you don't need to recompile the solver each time you make changes to the model, which is quicker. Compiling it this way involves the following steps:

* download the cvode solver from the [https://computation.llnl.gov/casc/sundials/download/download.html cvode/sundials website] At the time of writing that is cvode-2.5.0.tar.gz

* decompress cvode-2.5.0.tar.gz, and add the directory /include/threw/ from the threw model to ''cvode-2.5.0/include''. Replace the file ''cvode-2.5.0/src/cvode/cvode.c'' with the one included in the THREW model.

* Compile the solver with the changes we just made. This can be done with the following commands from within the cvode-2.5.0 directory. Note: we do not need to install the library (''make install'') since we will just copy the static libraries for use in threw.

./configure
./make

* copy the static libraries, which reside in a hidden directory

cp src/cvode/.libs/libsundials_cvode.a ./
cp src/nvec_ser/.libs/libsundials_nvecserial.a ./

* then copy both files (''libsundials_cvode.a'' and ''libsundials_nvecserial.a'') into the ''src'' directory of the THREW model. You may now throw away the cvode-2.5.0/ folder since both files (which are static libraries) contain all the functionality we need.

* Now you should be able to compile the threw model with the following command:

gcc -pipe threw_closure.c threw_error.c threw_f.c threw_init.c threw_io.c threw_utility.c threw2.c -o threw2 \
-L. -lsundials_cvode -lsundials_nvecserial -I../include

Why do we need to patch the solver? Only one thing changes: after each hydrological time step the function ''W2Flux()'' is executed. This is necessary to add external fluxes, such as rain. In its original form, the solver solves a differential equation from a certain initial state without further external intervention. In a hydrological model however, we may need to update the internal states after each timestep, for instance by adding rain, or taking away evapotranspiration. This is what ''W2Flux()'' does.

== the solver ==

Get your head around the solver in threw takes a bit of time. Here is a little explanation of what actually happens.

The core of the solver is the following line in threw2.c:

CVode(cvode_mem, tout, w, &t, CV_NORMAL)

This function solves the differential equations up to time ''tout''. ''tout'' is the time at which output is shown on the screen while the model is running, and may cover many hydrological time steps. ''w'' is a vector of results at this timestep.

TODO: where is ''tout'' defined, and we may want to check the above is correct by altering ''tout''. This should only have an impact on what is shown on the screen, but not on the final model results

All the data for running the model are stored in the structure ''cvode_mem''. This is a very complex structure that is understood by the solver. It contains everything from model state variables, parameters, as well as the 'right hand side function'. It is this function that is solved by the solver. It is basically the entire hydrological model, represented as a set of differential equations. In the threw code, the function is constructed in threw_f.c. It ''contains'' all the closure relations, which, individually, are defined in threw_closure.c.

=== Structure of the RHS function ===

todo

=== Structure of cvode_mem ===

todo

== Developers and applications ==

afaik, the following institutes / persons use a version of the REW model

* University of Illinois at Urbana Champaign
* University of Bristol (Wouter Buytaert)
* T U Munchen

Wbuytaert:

[[Category:Projects]]
[[Category:Hydrology in R]]

==Introduction==

The TOPMODEL package contains an implementation of the venerable TOPMODEL, along with some other useful functions. Although the package has been tested extensively, it may be contain bugs. All feedback is welcome (see the feedback page).

Thanks go to [http://www.lec.lancs.ac.uk/cswm/Staff_kb.php Keith Beven], who wrote the original TOPMODEL in Fortran, and [http://geni.ath.cx/ Huidae Cho], for the C code base (originally implemented in [http://grass.osgeo.org/ GRASS GIS])

For a fully documented example, see the [[Running Topmodel]] page.

==Downloads==

* [http://www.paramo.be/topmodel/topmodel_0.3.zip Windows binary]
* [http://www.paramo.be/topmodel/topmodel_0.3.tar.gz Linux source package]
* [http://www.paramo.be/topmodel/topmodel_0.3.tgz Universal MacOS X package]

==Installation==

===Windows===

Local packages can be installed from the menu. Choose "install package(s) from local zip files" and select the downloaded topmodel_0.3.zip file.

===Linux===

Use the normal procedure of installing a package in R:

> R CMD install topmodel_0.3.tar.gz

Developer tools, including gcc, must be installed.

===Mac===

Go to the Package Installer (Packages and Data menu), select "Local Binary Package", click install and select the downloaded package

==Loading==

Once in R you need to load the package before you can use it:

> library(topmodel)

==Function overview==

Full documentation is provided in the package, and can be opened with:

> help.start()