Click for movie of sea-turtle track near Nova Scotia (Dalhousie University) |
The GEON Integrated Data Viewer - Contents
INTRO
Introducing the GEON IDV
INSTALL
Download & Run the GEON IDV
YOUR DATA Data Formats for the IDV |
Track Data for the GEON IDV
Aircraft, vertical soundings, borehole logs, balloons, drifting buoys, ships, and animal migrations
Track or path data is a sequence of points in latitude, longitude, and time, on, above, or below the earth or ocean surface, with, optionally, observed data values at each point. The IDV can display the track as a sequence of point symbols which you may animate in time, or as a continuous line ("a trajectory"). The data values also can be seen in a table. You can change the point size or symbol, or line thickness, and color scheme with IDV controls. Track displays in the IDV can be colored by measured data values along the path.
There are two NetCDF formats and one ASCII format described on this web page. Any format can be used for any track or path purpose.
IDV Text Point Data Format Files - the simplest Track Format ... Land animals on 3D topographic relief ... Marine Mammals or Drifting Buoys
Aircraft Track Data (3D paths above the surface)
Vertical Soundings (3D paths below the surface)
Animal Track Data (Mapped tracks on the surface, including 3D topography surfaces)
How to Work with Track Data in the IDV
IDV Text Point Data Format Files - the simplest Track Format
. See more about using bundle files.This simple ASCII format may be used for any track purpose, including land and sea surface tracks, and paths above or below the surface from aircraft to seismic ray paths. It can also be used for vertical boreholes and soundings.
Here is a sample IDV ASCII track data file. It is a comma separated value (csv) file, with one line per data location and time (point observation). You can use it as a template for your own data. The particular data in the file simulates tracking a bear at 18 locations and times in Colorado.
The example csv data file has five columns (Time, Latitude, Longitude, Altitude, and sensor_1 values) in each row. You should keep the first four columns as they are; you may rename the "sensor_1_values" item, and add more sensor values types. Altitude is optional but time, latitude and longitude are not. If you want to display the data in a 3D display at precisely the correct level, use altitude even if all values of altitude are the same. If oyu do not supply altitude values you can still slide the path vertically up and down in the IDV 3D display area. Negative altitude values are below sea level (O.0 in the IDV vertical scale). The sensor values are any kind of observed data value at each location and time. Senso unit can be "null."
Read more details about Text (ASCII) Point Data Format from the UNAVCO IDV help
When you load a data source like this in the IDV Dashboard's Data Chooser, select "Data Source Type" of "Text Point Data Files " (not "Track files" which is for NetCDF formatted track files).
These tracks can be displayed with "accumulating time animation" showing the progress along the track with time.
A Bundle file to create this track data display in the IDV (data is online)
Sample IDV Displays of ascii track data:
Land animals on 3D topographic relief
map view of the ASCII data file
movie of 3D oblique view of part of track, with 3D topographic relief(animated gif file; 2 MB)
Marine Mammal Tracks or Drifting Buoys
IDV movie of marine mammal track
(3 MB)
Alternately, you can show a track as a continuous line, optionally colored by data value at each point.
For the line, use the Data Chooser
"Data Source Type" "Text Point and Trajectory Data Files:"
In the choice of Dashboard's Field Selector panel,
click the parameter to control the color (named bmode here), and choose
Displays type "Track:"
Marine track data provided by Maswood Hasan Mostafi, Dalhousie University. Displays by UNAVCO.
3D oblique view of track, with 3D topographic relief using USGS DEM files (topography data). The region is the Colorado Rockies with county lines in red.
click for full size
Click for full size
marine mammal track (points by time)
with 2d sea surface elevation data
(data provided by Maswood Hasan Mostafi, Dalhousie University)
marine mammal trajectory - path line colored by value
