[GRASS-dev] image processing modules for GRASS GIS

Yann yann.chemin at gmail.com
Fri May 18 16:39:29 EDT 2007


Hi all,

There is a group of modules about satellite image processing in the GRASSSVN 
Add-ons repository that I am working on. Today, i've been suggested to write 
this email.

I would like to ask whether some people would be interested in expanding the 
standard raster menu of GRASS with some of these modules contained in this 
set. A large part is composed of r.eb.* modules, dedicated to energy balance 
calculations ultimately leading to Actual evapotranspiration estimations.

Already i.atcorr was in GRASS 5.x, and there were interests to return it into 
6.x. 

thanks
Yann

Additional info below:


This is a Brief ID card 
-------------------------------------------------------------------------------------------------
Name: GIPE, the GRASS Image Processing Environment.

Objective: To group a set of modules aiming at processing some common 
satellite imagery from Digital Number up to some high level products that may 
be useful on their own. A clear interest is in the many modules of 
Evapotranspiration (ET: mm/day), but some others are there too (biomass, 
Vegetation Indices, Albedo, etc).
 
Number of modules: 33 so far (+2 from other authors: h.evapo.PM and i.atcorr)
-------------------------------------------------------------------------------------------------




The list of modules
-------------------------------------------------------------------------------------------------
Extern:
- i.atcorr: 6s atmospheric correction model wrapper, ported to 6.x cvs, 
including needed code cleaning
- h.evapo.PM: renamed r.evapo.PM, Potential ET after Penman and Monteith

List:
- r.dn2ref.l7: convert DN to radiance and/or reflectance for Landsat 7 
- r.dn2full.l7: use .met file to convert all automatically into reflectance 
(including temperature radiance for temperature bands)
- r.dn2ref.ast: convert DN to radiance and/or reflectance for Terra Aster ( 9 
bands)

- r.vi: 13 types of vegetation indices (mpi and Ninf/G grid versions for 
educational purposes)
- r.albedo: input to r.sun, calculates Albedo from NOAA AVHRR, MODIS, Landsat 
and Aster.

- r.latitude: calculates a latitude map (degrees)
- r.sunh: calculates potential sunshine hours
- r.sath: calculates the satellite overpass time

- r.evapo.MH: Reference ET after Hargreaves and Modified Hargreaves
- r.evapo.PT: Potential ET after Prestley and Taylor
- r.evapo.potrad: Potential ET from Net radiation
- r.dn2potrad.l7: use .met file of Landsat 7 to calculate potential ET 
directly from Digital Numbers.

- r.eb.eta: ET calculation after SEBAL
- r.eb.z0m: surface roughness estimation
- r.eb.deltat: difference air-surface temperature
- r.eb.netrad: net radiation
- r.eb.disp: displacement height
- r.eb.molength: Monin-Obukov Length
- r.eb.psi: Psichrometric parameters for heat 
- r.eb.ublend: blending height wind speed 
- r.eb.ustar: nominal wind speed
- r.eb.rah: aerodynamic resistance to heat transport
- r.eb.g0: soil heat flux
- r.eb.h0: sensible heat flux
- r.eb.h_iter: sensible heat flux with iterative adjustment of some parameters
- r.eb.evapfr: evaporative fraction calculation and soil moisture estimation

- r.biomass: Calculate biomass growth of a plant (main input to yield 
estimations)

(these are not image processing directly, but they got created on some job so 
i keep them in the same place)
- r.uslek: Calculates the USLE K factor from percentage of sand, loam, clay 
and organic matter.
- r.usler: Calculates USLE R factor from any one of 4 different standard 
equations.



-- 
Yann Chemin
Sainte-Anne d'Auray, France




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