The U.S. government is closed. This site will not be updated; however, NOAA websites and social media channels necessary to protect lives and property will be maintained.

To learn more, visit commerce.gov.

For the latest forecasts and critical weather information, visit weather.gov.

Home Introduction Download Receptor File Configuration File Creating a Landmask File Spatial Distances Stage 1 - Creating H Slices Stage 2 - Applying Sprior sigma to H Slices and Calculating HQ Stage 3 - Observations, background and priors Stage 4 - Inversion and posterior uncertainty Changelog

CarbonTracker Lagrange Documentation

Stage 3 - Observations, background and priors

The solution of Equation 1 requires a prior estimate of s (called sp or sprior). The user must create the sprior file with dimensions ntimesteps x nlandcells, so there is a value for each land cell at each time step.

Equation 1 also uses z, a vector of measurements for use in the term (z-Hs_p). This term is defined as

(z-Hs_p) = (observation - bg - Hsp - Hother )

The program make_z.py makes these calculations and creates one file used in the inversion,

  • zhsp.txt - contains (z-Hs_p), dimensions (nobs)

and several additional files for information:

  • obs-bg.txt - Observation values minus the background values.
  • hsprior.txt - H convolved with sprior.

Prerequisites

  • observation list - File with observation values, one value per line for each receptor.
  • background list - File with background values, one value per line for each receptor.
  • sprior - contains sp. Can be either a numpy save file, dimensions (ntimesteps x ncells), or a netcdf file, with a variable named ‘sprior’ and dimensions (ntimesteps x nlat x nlon)
  • H blocks created by hsplit.py.
  • (Optional) hother, one value per line for each receptor, with additional values to subtract from z.

Usage

make_z.py is run with:

Usage: make_z.py [--other=otherdata] [-c configfile] obsfile spriorfile backgroundfile

where

  Reguired arguments
        obsfile            : file with observation value, one line per receptor.
        spriorfile         : file with sprior data. It can be either .npy or netcdf format.
        backgroundfile     : file with background value, one line per receptor. Default is 'bg.txt'.

  Optional arguments
        -c configfile      : file with configuration data.  Default is 'config.ini'.
        --other=otherdata  : file with other values to subtract from observations, one line per receptor.


  Output:
        zhsp.txt    - Observations minus background minus hsprior minus hother
        hsprior.txt - H convolved with sprior
        obs-bg.txt  - Observations minus background