KCARTA - the kCompressed Radiative Transfer Algorithm


The kCARTA code provides a means to calculate on a "pseudo line by line" basis, atmospheric optical depths as well as radiances at arbitrary pressure levels, for either a downlook or an uplook instrument. The user needs to provide a specificed atmospheric profile, surface, and instrument viewing parameters. In addition kCARTA can compute analytic jacobians extremely rapidly. The complete KCARTA package consists of four pieces:
1) the KCARTA source code, written in F77
2) the KCARTA optical depth kCompressed database, available for big-endian and little-endian machines,
3) the kCARTA auxiliary data files (top of atmosphere solar radiances, water continuum files, test regression profiles, sea surface emissivities etc),
4) the RTP input/output library.
In addition, any user will also need the kLAYERS level-to-layer package. Users are also advised to pick up the Matlab package to read output files produced from kCARTA runs, as well as "kcwrap" that allows the user to put in point profiles into an RTP file, and output AIRS SRF convolved results (after appropriate calls to kLAYERS and kCARTA).

Latest & Greatest

We continually refine KCARTA. The clear sky radiative transfer code has not had any significant changes or bugfixes since about 2004, and development has been "frozen" at v1.10. However we actively update the optical depth kCompressed Database by validating kCARTA results against measured AIRS radiances. New versions of the KCARTA v1.10 code and/or database will appear here as new features are added, or bugs are corrected.

We are testing and implementing scattering algorithms, as well as NonLocal Thermodynamic Equilibrium algorithms, for use with kCARTA. These will be released in later versions of kCARTA (v1.11 and up) when we feel we are ready to give them out.

New : A Matlab version of kCARTA

Source code versions

KCARTA clear sky bugfixes source code v1.20 15 June 2018
KCARTA clear sky bugfixes source code v1.18 15 May 2018
KCARTA clear sky bugfixes source code v1.16 15 May 2012
KCARTA clear sky bugfixes source code v1.10 20 Feb 2009
KCARTA aux files/directories v1.14 27 Jul 2010
KCARTA clear sky source code v1.10 30 Jun 2005

KCARTA Matlab readers 30 Jun 2005
Auxiliary rtpread/write Matlab readers 11 Aug 2010

RTP I/O library
KCARTA wrapper 30 Jun 2005
RTP I/O library

kCARTA Databases

link to the KCARTA kCompressed database(s)
KCARTA auxiliary data 30 Jun 2005

Related Packages

The klayers package converts atmospheric profiles at discreet point levels into integrated slab layer profiles of the type used by KCARTA and SARTA. klayers uses the RTP I/O format, making it very convenient for use with KCARTA and SARTA.

klayers v2.04 23Jun05

MATLAB users who will be working with RTP files will definitely want to pick up our basic RTP I/O toolkit.

basic RTP I/O toolkit for MATLAB

Tabulated AIRS Spectral Response Functions (SRFs) are available here.

AIRS SRF files

The AIRS Stand Alone Radiative Transfer Algorithm, developed from kCARTA, is available here

SARTA web page

Postscript and pdf copies of the kCARTA user manual are available here

ps user manual
pdf user manual

Compiler considerations

The source code is written in FORTRAN77, but it makes use of "structure" variables which are a non-standard extension, and so not all FORTRAN77 compilers will work with kCARTA. For example, the Gnu g77 compiler will not work. The kCARTA package has been tested with the following unix/linux FORTRAN compilers: Absoft, Portland Group, Sun, SGI.


Sergio DeSouza-Machado (author)
kCARTA description
Atmospheric Spectroscopy Lab group,UMBC
Sergio De Souza-Machado