This section has been superseded by the treatment of trajectories as a type of discrete sampling geometry in Chapter 9.

A possible representation of the spatiotemporal locations of measurements along a flight path is to use time to parameterize the trajectory and use auxiliary coordinate variables to provide the spatial locations.

**Example 5.5. Trajectories**

```
dimensions:
time = 1000 ;
variables:
float O3(time) ;
O3:long_name = "ozone concentration" ;
O3:units = "1e-9" ;
O3:coordinates = "lon lat z" ;
double time(time) ;
time:long_name = "time" ;
time:units = "days since 1970-01-01 00:00:00" ;
float lon(time) ;
lon:long_name = "longitude" ;
lon:units = "degrees_east" ;
float lat(time) ;
lat:long_name = "latitude" ;
lat:units = "degrees_north" ;
float z(time) ;
z:long_name = "height above mean sea level" ;
z:units = "km" ;
z:positive = "up" ;
```

`O3(n)`

is associated
with the coordinate values `time(n)`

,
`z(n)`

, `lat(n)`

, and
`lon(n)`

.