"obs_stats" is a package to do long-span stats from AIRS and CrIS
SDR and other supporting data, with minimal obs subsetting.


Recent Tests and Data
======================

An "obs list" is a subset of AIRS or CrIS SDR data, typically a
latitude weighted subset of all obs for 16-days, for a small subset
of channels.  A "map table" is an nchan x nlat x nlon x nset table
or array of maps of 16-day maps mean and variance, usually for a
full year (23 16-day sets).  A "PDF table" is an nbin x nlat x nlon
x nset table of 16-day PDF maps, also usually for a full year.

It takes some time to tabulate the obs lists--around a week, to do
all the AIRS data--but doing stats from the obs lists is relatively
fast; maybe a couple of hours to look at every obs list file.  
Similarly, it takes a couple of hours to build the map or pdf tables
from the obs lists, but doing stats from the tables is very fast, a
few minutes at most.

The obs_source directory has scripts and functions to tabulate obs
lists, map tables, and pdf tables, and to do stats on the map and
pdf tables.  See obs_source/README for more info.

The source directory has general support and utility functions for
the obs stats package; see source/README for more info.

recent data
-----------
obs_16day_airs_c* - 16-day AIRS obs lists for channel set c<n>
obs_16day_cris_c* - 16-day CrIS obs lists for channel set c<n>
map_16day_airs_c* - 16-day map tables for AIRS channel set c<n>
pdf_16day_airs    - 16-day PDF tables for one channel of AIRS data


Older Tests And Data
=====================

geo tests
----------
AIRS and CrIS geo obs list scripts and functions.  These read AIRS
or CrIS SDR files and tabulate lat, lon, time, and zenith angles for
all obs over a set of days and a selected scan pattern, and do stats
on the resulting obs lists.  See the README files in geo_source and
geo_data

obs_quint_source
-----------------
These are earlier versions of obs list functions that work with
quintiles (73-day sets).  See obs_quint_src/README for more info.

tbin tests
-----------
The tbin or PDF functions take parameters year, day list, cross
track indices, frequency span, and (with in-line mods) ocean or land
subsets.  They read every granule over the requested span and build
tables of obs per Tb bin by day.   Scripts are in tbin_source, data
in airs_pdfs, cris_pdfs, and pdf_test_*.

  airs_tbin   - tabulate AIRS Tb bins
  cris_tbin   - tabulate CrIS Tb bins
  airs_batch  - batch driver for airs_tbin
  cris_batch  - batch driver for cris_tbin
  plot_tbin   - compare AIRS and CrIS
  plot_airs   - multi-year basic AIRS PDF stats
  airs_pdfs   - multi-year AIRS moving-span PDFs

  pdf_test_*  - more recent tbin or PDF test data
  airs_pdfs   - AIRS tbin data for 2002-2017, to 340K
  cris_pdfs   - CrIS tbin data for 2015-2016, to 340K