It took a bit of research but I figured out how to create a math channel that calculates distance from the Lat/Long channels. The contents are below in case anyone else wants to try it. It was largely adapted from this article here - https://stackoverflow.com/questions/365826/calculate-distance-between-2-gps-coordinates

/* Calculate distance using the difference between current and last GPS coordinates. */

register @distance = 0;

register @lat1 = [Latitude];

register @lon1 = [Longitude];

register @lat2;

register @lon2;

register @pi = 0.0174532925199433; //pi / 180

register @radius = 3959 * 5280; //radius of Earth in ft

register @dLat;

register @dLon;

register @lat1Rad;

register @lat2Rad;

register @a;

register @c;

@lat2 = [Latitude];

@lon2 = [Longitude];

@dLat = (@lat2-@lat1) * @pi;

@dLon = (@lon2-@lon1) * @pi;

@lat1Rad = @lat1 * @pi;

@lat2Rad = @lat2 * @pi;

@a = sin(@dLat / 2) * sin(@dLat / 2) + sin(@dLon / 2) * sin(@dLon / 2) * cos(@lat1Rad) * cos(@lat2Rad);

@c = 2 * atan2(sqrt(@a), sqrt(1-@a));

@lat1 = @lat2;

@lon1 = @lon2;

@distance = @distance + (@radius * @c);

@distance