Real-time drifter tracking system for coastal studies

Pimenta, Felipe M.; Silva, Gabriel L. M. da; Assireu, Arcilan T.; Saavedra, Osvaldo R.; Garcia, Carlos A. E.; Guimarães, Pedro V.; T. Junior, Audálio R.; Nassif, Felipe B.; Lopes, Denivaldo C. P.; Santos, Marcio C. F. Vaz dos

doi:10.1590/2675-2824074.25157

Table of contents previous current next

Table of contents

ORIGINAL ARTICLE • Ocean Coast. Res. 74 (suppl 1) • 2026 • https://doi.org/10.1590/2675-2824074.25157 linkcopy

Real-time drifter tracking system for coastal studies

Authorship SCIMAGO INSTITUTIONS RANKINGS

This article presents a real-time drifter tracking system designed to investigate circulation and transport processes in coastal environments. Field demonstrations were conducted in two contrasting Brazilian coastal regions: Florianópolis Island in the south, a microtidal area driven primarily by wind circulation, and São Marcos Bay in the northeast, an estuary complex characterized by strong tidal forcing. Surface Velocity Program (SVP) drifters were adapted for coastal applications, incorporating a reel to adjust drogue depth and electronic systems housed in a 3D-printed enclosure. The tracking system was also tested with an undrogued iSphere drifter to assess estuarine surface circulation. Satellite communication systems enabled real-time tracking for efficient deployment and recovery of drifters, while optional fast-response loggers ensured near-continuous data collection. Results revealed rapid circulation responses to wind forcing north of Florianópolis Island, and a tidal-dominated environment in São Marcos Bay, with secondary influence from wind and waves. The real-time tracking system prevented equipment loss and enhanced data acquisition. This reusable drifter setup offers a practical solution for oceanographic studies, supporting repeated deployments, streamlined data collection, and adaptability to various coastal applications and drifter types.

Keywords:
SVP drifter; iSphere; Coastal circulation; Florianópolis; São Marcos Bay

Surface drifter components	L (cm)	D (cm)	A (m²)	Cd	Cd A	Drag force (N) from 10 m s^-1 winds
Tracker shelter	10	15	0,0150	0,600	0,0090	0,54
Flag	20	15	0,0600	0,010	0,0006	0,04
Aluminum square mast	65	0,8	0,0052	2,200	0,0114	0,69
Lantern	26	4,8	0,0125	0,820	0,0102	0,61
Surface buoy (emerged)	-	40	0,0628	0,500	0,0314	1,88
Total					0,0627	3,76
Subsurface drifter components						Drag force (N) from currents
Subsurface drifter components						0.5 m s^-1	2.0 m s^-1
Surface buoy (submerged)	-	40	0,0628	0,500	0,031	4,03	64,40
Buoy urethane connection	40	4	0,0080	1,000	0,008	1,03	16,40
Cable	300	1	0,0300	1,400	0,042	5,38	86,10
2 reel disks	-	15	0,0353	1,000	0,035	4,53	72,45
Reel axis	50	2	0,0100	1,300	0,013	1,67	26,65
Spaghetti float	30	6	0,0180	0,800	0,014	1,85	29,52
Drogue urethane connection	40	4	0,0080	1,000	0,008	1,03	16,40
Drogue	620	60	3,7200	1,400	5,208	667,28	10676,40
Total					5,360	686,77	10988,33
Ratio subsurface/surface					85,50	182,59	2921,36
Ratio drogue/(buoy+cables)					36,18	36,18	36,18

Spot Trace
Transmission interval Δt	Battery life (constant movement)	Drift distance (m) at Δt
Transmission interval Δt	Battery life (constant movement)	0.25 m s^-1	0.5 m s^-1	2 m s^-1
60 min	60 days	900 m	1800 m	7200 m
30 min	35 days	450 m	900 m	3600 m
15 min	20 days	225 m	450 m	1800 m
10 min	13 days	150 m	300 m	1200 m
5 min	8 days	75 m	150 m	600 m
2½ min	6 days	37.5 m	75 m	300 m

i-gotU
Recording interval Δt	Battery life (constant movement)	Drift distance (m) at Δt
Recording interval Δt	Battery life (constant movement)	0.25 m s^-1	0.5 m s^-1	2 m s^-1
60 seconds	16.6 days (400 hrs)	15 m	30 m	120 m
30 seconds	10 days (240 hrs)	7.5 m	15 m	60 m
15 seconds	6.25 days (150 hrs)	3.75 m	7.5 m	30 m
10 seconds	1.88 days (45 hr)	2.25 m	5 m	20 m
5 seconds	1.6 days (40 hrs)	1.25 m	2.5 m	10 m
1 second	1.6 days (40 hrs)	0.25 m	0.5 m	2 m

location_on

Instituto Oceanográfico da Universidade de São Paulo Praça do Oceanográfico 191, CEP: 05508-120, São Paulo, SP - Brasil, Tel.: (11) 3091-6501 - São Paulo - SP - Brazil
E-mail: diretoria.io@usp.br

rss_feed Stay informed of issues for this journal through your RSS reader