Mariner AO

From GeoMod

The object of this program is to create a game that allows users to sail around the world using global wind patterns that are either generated (to allow simplified global circulation patterns) or taken from global data sets.

Contents 1 Options 2 Specification 2.1 Database 3 Sources 3.1 On Google maps 3.2 Data Sources 3.3 Media 3.4 Javascript 4 Development

Options

• Google Maps: use google maps as the interface for the model.
  • Advantages:
    • Google maps has excellent maps and a lot of built-in map functions and high resolution.
    • Instantly online
  • Disadvantages:
    • Will have to use JavaScript.
    • Will depend on Google keeping the API open and free

Specification

Database

Sources

On Google maps

• Google Maps Widgets from Bill Chadwick: http://www.bdcc.co.uk/Gmaps/BdccGmapBits.htm
  • Excellent source for good examples using all sorts of SVG and other techniques to overlay the google maps.
• Google Maps API Tutorial: http://econym.org.uk/gmap/
  • Good source of basic information.

• Code to get bearing and distances
  • http://econym.org.uk/gmap/example_dist.htm

• Drawing great circles and plotting a course.
  • http://www.movable-type.co.uk/scripts/latlong.html - finding final location given initial location and bearing.
  • http://www.acscdg.com/

• AJAX resources:
  • http://ajaxmashup.googlepages.com/ajaxGoogleMapsMashup.html
  • http://www.netmag.co.uk/zine/ajax/working-with-google-maps
  • http://www.w3schools.com/Ajax/ajax_xmlhttprequest.asp
  • http://www.javascriptkit.com/jsref/select.shtml#section2

Data Sources

• Surface wind stress: http://dss.ucar.edu/datasets/ds110.1/
  • Trenberth, K.E., W.G. Large, and J.G. Olson, 1989: A Global Ocean Wind Stress Climatology Based on ECMWF Analyses. TN-338+STR, National Center for Atmospheric Research, 93 pp.

• Surface ocean currents: http://www.oscar.noaa.gov/datadisplay/datadownload.htm
  • Data from OSCAR

• Global topography:
  • From NGDC: http://www.ngdc.noaa.gov/mgg/bathymetry/relief.html
    • ETOPO2v2 Global Gridded 2-minute Database (cell centered): http://www.ngdc.noaa.gov/mgg/global/global.html
      • Actual file: http://www.ngdc.noaa.gov/mgg/global/relief/ETOPO2/ETOPO2v2-2006/ETOPO2v2c/netCDF/ETOPO2v2c_f4_netCDF.zip
  • regridded to 2.5 degree grid using GMT (Generic Mapping Tools): http://gmt.soest.hawaii.edu/
  • GMT installed using fink.
    • Data regridding command:
      • > grdsample ETOPO2v2c_f4.nc -I180m -Gworldtopo.grd
      • where ETOPO2v2c_f4.nc is the datafile downloaded from NGDC and worldtopo.grd is the output file. 180m is the 2.5 degree cell spacing (m = minutes).
    • Converting to ASCII
      • > grd2xyz worldtopo.grd > worldtopo.dat
      • where worldtopo.dat is the ASCII file in x,y,z format.
  • USGS web service for topography

• Navigation math: Calculate distance, bearing and more between two Latitude/Longitude points by Chris Veness
  • http://www.movable-type.co.uk/scripts/latlong.html
  • Great page with formulas for getting distances between 2 lat/long coordinates and getting the new lat/long given a starting co-ordinate and a bearing.
• Converting a vector into a bearing and a magnitude: http://mst.nerc.ac.uk/wind_vect_convs.html

Media

Blank world map used as a background. From Wikipedia.

Javascript

• http://jennifermadden.com/javascript/stringEnterKeyDetector.html - Handling onKeyPress

Development

DEVELOPMENT