conversion XYZ to Latitude/longitude

I looked for a software to convert from XYZ to latitude/longitude, and found a good tool from internet.

---From the website http://www.ngs.noaa.gov/PC_PROD/XYZWIN/, I downloaded a ZIP'ed archive that includes the C source code, and all documentation.


---make xyz2llh
(remove the *.o if they exist, then compile the code)


-- test with ./run3.csh,  ./run2.csh and ./run1.csh. It should work


Note:
0)  ./xyz2llh
xyz2llh(1.5 02/02/07): Converts X Y Z to lat, lon and ellipsoid hgt
Usage: xyz2llh X Y Z
  options:
           -d print deg min sec rather than decimal degrees.
           -h prints this message.
           -r = input coordinates are lat, lon, hgt,
                output coordinates will be X, Y, Z.
           -w longitudes are west rather than east longitude.

1) example:

./xyz2llh -w  -5246403.93847269, -3077285.30866971, -1913839.28749343

results:  lat=-17.5770292180   long=149.6061879567     hight=99.81636

Attention: this code does not require the definition of reference Ellipsoide, and it uses WGS84 by default. Sometimes we may be interested in other option, such as ITRF2005, which is however not used by this code. The results between using different  reference Ellipsoide could be large, eg., 50 cm difference at height.

google earth engine

The news is from http://earthengine.googlelabs.com/#intro.

Goole developed a planetary-scale platform for environmental data & analysis.
Google Earth Engine brings together the world's satellite imagery—trillions of scientific measurements dating back more than 25 years—and makes it available online with tools for scientists, independent researchers, and nations to mine this massive warehouse of data to detect changes, map trends and quantify differences to the earth's surface.

Using this new tool, google has begun helping scientists develop applications for detecting deforestation and mapping land use trends, and have started working with individual countries to develop their own applications.

It seems worth trying ....