BLOG POST: Using CartoDB to visualize how far birds migrate in a single night
Read about the nightlife of birds in this latest LifeWatch INBO blog post!
Last week the LifeWatch INBO team participated in a very productive workshop in Amsterdam organized by working group 3 of ENRAM. ENRAM is the European Network for the Radar Surveillance of Animal Movement funded by COST and the workshop was a follow-up on the hackathon at which the flow visualization was created last year.
One of the goals this year was to visualize forward trajectory model data for bird migration. This was inspired by the fabulous Alcatraz escape simulation made by Dutch researchers in CartoDB.
Long-range surveillance radar
The source data for these visualizations were gathered and processed by a bird radar detection system called ROBIN. The ROBIN system received a radar signal from two long-range surveillance radars in Belgium and the Netherlands. Every half hour radar measurements were sampled from ten successive high-resolution images and processed to extract location, ground speed, and track direction of individual birds or flocks. For this project data was used from the first two hours after sunset on April 6 and 7, 2013. During this period birds take-off from the radar locations to continue their nocturnal spring migration.
Forward trajectory model
For each individual bird track time, location, ground speed, and track direction were extracted and the airspeed and heading was calculated using the wind at 925hPa. These parameters were used to simulate a forward trajectory based on a model described in Shamoun-Baranes & van Gasteren 2011. By keeping the birds’ airspeed and heading constant, influences of wind will effect new positions each 5 minutes and result in the presented forward trajectory until sunrise. Strong following winds during the night or location can increase the ground speeds above 100 km per hour.
Read the blog post below to see vizualizations about:
One of the goals this year was to visualize forward trajectory model data for bird migration. This was inspired by the fabulous Alcatraz escape simulation made by Dutch researchers in CartoDB.
Long-range surveillance radar
The source data for these visualizations were gathered and processed by a bird radar detection system called ROBIN. The ROBIN system received a radar signal from two long-range surveillance radars in Belgium and the Netherlands. Every half hour radar measurements were sampled from ten successive high-resolution images and processed to extract location, ground speed, and track direction of individual birds or flocks. For this project data was used from the first two hours after sunset on April 6 and 7, 2013. During this period birds take-off from the radar locations to continue their nocturnal spring migration.
Forward trajectory model
For each individual bird track time, location, ground speed, and track direction were extracted and the airspeed and heading was calculated using the wind at 925hPa. These parameters were used to simulate a forward trajectory based on a model described in Shamoun-Baranes & van Gasteren 2011. By keeping the birds’ airspeed and heading constant, influences of wind will effect new positions each 5 minutes and result in the presented forward trajectory until sunrise. Strong following winds during the night or location can increase the ground speeds above 100 km per hour.
Read the blog post below to see vizualizations about:
- nocturnal bird migration on the night of April 6-7, 2013 (night 1)
- nocturnal bird migration on the night of April 7-8, 2013 (night 2)
- migration of songbirds and waterbirds based on airspeed on the night of April 7-8, 2013 (night 3)
