MATLAB Examples

# reftrack documentation

The reftrack function returns coordinates of ICESat's 91-day orbit reference tracks.

## Syntax

```[lat,lon] = reftrack(track)
[lat,lon] = reftrack(...,'spacing',SpacingMeters)
[x,y] = reftrack(...,'xy')```

## Description

[lat,lon] = reftrack(track) returns georeferenced coordinates of any ICESat track given by scalar track number.

[lat,lon] = reftrack(...,'spacing',SpacingMeters) specifies along-track spacing in meters. Default spacing is 1000 meters.

[x,y] = reftrack(...,'xy') returns coordinates in polar stereographic (true latitude 71 S) meters.

## Example 1: Simplest case

Get geo coordinates of ICESat track 1304:

```[lat,lon] = reftrack(1304); ```

Now we can plot track 1304 as a red line on a georeferenced map like this:

```bedmap2('gl') plotm(lat,lon,'red') ```

## Example 2: Specify spacing

Perhaps you want to have a specified spacing, like ever 172 meters along track. No problem! Do that like this:

```[lat,lon] = reftrack(1304,'spacing',172); ```

## Example 3: Polar stereographic coordinates

If you prefer your data in polar stereographic coordinates, you can either convert the data yourself by [x,y] = ll2ps(lat,lon) or you can simply include the 'xy' option:

```[x,y] = reftrack(1304,'xy'); ```

Now we can plot x,y as a blue line in cartesian coordinates:

```figure bedmap2('patchcoast','xy') plot(x,y,'b') ```

## Author Info

The reftrack function and supporting documentation were written by Chad A. Greene of the University of Texas at Austin's Institute for Geophysics (UTIG) in December 2015.