What is TIRCIS
--------------

TIRCIS is a project at the Hawai`i Institute of Geophysics and Planetology
(UHM), which has developed a prototype of a hyperspectral thermal infrared
imager for Earth surface, to be used in small satellites.  (Picture of the
prototype: http://www.higp.hawaii.edu/~wright/tircis.jpg) It allows the
quantifying of the chemical composition of targets (e.g., volcano plumes).

Here is a 20014 abstract: https://esto.nasa.gov/forum/estf2014/presentations/B4P6_Wright.pdf

The code in this directory is used to processes the hyperspectral data obtained from from TIRCIS.

How to build it 
-----------------

Install some packages:

% sudo apt-get install make g++
% sudo apt-get install fftw3-dev
% sudo apt-get install libopencv-dev

Compile it:

% make clean; make

The Makefile in this directory calls make in ./tircis_process_cmd_v0/ and
./testdata/.  The Makefile  in ./tircis_process_cmd_v0/ is pretty simple and
produces an executable that is then copied into the ./testdata/ directory.
The Makefile in ./testadata/ does some string-replacing in the newproc.txt
configuration file which, for some reason, wants absolute paths (check it
out if you want to see some command-line fun). It also compiles a small
program that I wrote and that will come in handy.


How to run it
-------------

% cd testdata; ./tircis_process_cmd ./newproc.txt


How to check the output
-----------------------

When optimizing a piece of software, often one breaks it (i.e., it no
longer produces the desirable output). Sometimes, however, small variations
in output are unavoidable and tolerable (e.g., due to different round-off
errors after switching arithmetic operations around).  

For instance, compile the following C code and (likely) be amazed:

	int main() {
        	double x=0.1+(0.2+0.3);
        	double y=(0.1+0.2)+0.3;
        	if (x == y) {
                	printf("EQUAL\n");
        	} else {
                	printf("NOT EQUAL: %.20lf %.20lf\n",x,y);
        	}
	}


At any rate, you need a way to check that the output you produce in your
optimized version of tircis is still correct/acceptable.

To check the output your code produces in ./testdata/processed, simply do:

% cd ./testdata; make check

The Makefile in ./testdata/ calls a bash script (which in turns calls a C
program) to compare our output files byte-per-byte to the reference output
files in ./valid_output. If no differences are found, then nothing will be
printed out.

Also, you can visually inspect the output picture
./testdata/processed/phot_15_qtz_midband.png and compare to that in
./valid_output/phot_15_qtz_midband.png