Validation of a Smartphone App to Retrieve Turbidity in an Urban Lake: First Steps Towards a coupled Remote Sensing - Citizen Science Strategy

Código

XXIV-SBRH0349

Autores

Gabriela Rosalino Unfer, Lino Augusto Sander Carvalho, Daniel Andrade Maciel

Tema

SE07.B - Sensoriamento remoto da água: de avanços técnicos-científicos a aplicações na nova era de disponibilidade de informação

Resumo

Remote sensing technology based on smartphone applications has been contributing to in situ data acquisition and it is a well-known strategy to promote Citizen Science. In this work, an approach using in situ and orbital remote sensing data was developed for Lagoa Rodrigo de Freitas, located in the city of Rio de Janeiro, in order to validate HydroColor for urban lagoon water quality monitoring. HydroColor uses the smartphone camera to derive the remote sensing reflectance of water bodies and then calculate water quality parameters. Results show that HydroColor is substantially accurate to measure the reflectance of water in the red band and to estimate turbidity thus, being a potential tool for the validation of remote sensing products. Hydrocolor measurements presented values of Mean Absolute Percentage Error (MAPE) reaching 51% when compared to in situ radiometry and 17.7% when compared to in situ turbidity. When used as reference to Sentinel-2B products, HydroColor showed a MAPE of 31.3% in the red band and 19.2% for retrieved turbidity. From this study, HydroColor proved to be a suitable tool for citizen science which, coupled to orbital remote sensing, will increase the availability of open-source datasets, contributing to product validation and monitoring of highly impacted urban water bodies.