Computing US airport connections and route interpolations

Generating connections

In this example we will showcase how easily we can compute all the paths that interconnect the main four US airports using the Analytics Toolbox.

WITH data AS(
    SELECT *
    FROM `carto-do-public-data`.natural_earth.geography_glo_airports_410
	WHERE abbrev = 'JFK' OR abbrev = 'LAX'  OR abbrev = 'SEA'  OR abbrev = 'MIA'
)
SELECT `carto-un`.carto.ST_GREATCIRCLE(t1.geom, t2.geom, 25) AS geo
FROM data AS t1
CROSS JOIN data AS t2
WHERE t1.abbrev != t2.abbrev;

This query first creates all the possible combinations between airports and then generates the paths between them using the ST_GREATCIRCLE function. The resulting paths contain 25 points, but you can set the number of points in order to make the lines smoother if needed.

Routes interpolation

Now let’s put to the test how to perform line interpolations using the ST_LINE_INTERPOLATE_POINT function. In this example we will compute the airplane position after taking off from the different airports and travelling a certain distance.

WITH data AS(
    SELECT *
    FROM `carto-do-public-data`.natural_earth.geography_glo_airports_410
	WHERE abbrev = 'JFK' OR abbrev = 'LAX'  OR abbrev = 'SEA'  OR abbrev = 'MIA'
)
SELECT CONCAT(t1.abbrev, " - ", t2.abbrev) as route, `carto-un`.carto.ST_LINE_INTERPOLATE_POINT(`carto-un`.carto.ST_GREATCIRCLE(t1.geom, t2.geom, 25), 500,'kilometers') AS geo
FROM data AS t1
CROSS JOIN data AS t2
WHERE t1.abbrev != t2.abbrev;

This query uses the ST_LINE_INTERPOLATE_POINT function over each great circle in order to calculate the location of the plane after travelling 500 kilometers.