Combining recent advances in remote sensing and aerial survey, a new system for airborne current measurement has been developed to bridge the gap between satellite- and vessel-based ocean current measurements.ROCIS, the Remote Ocean Current Imaging System, combines Fugro expertise in airborne survey and operational oceanography with state-of-the-art technology and oceanographic research from Areté and Associates.
ROCIS uses an innovative surface current measurement technique to significantly enhance understanding of current phenomena in coastal and offshore areas.
Using high-resolution airborne photography, the system images surface waves and retrieves surface current data from the Doppler shift of successive surface wave images. Current data can be collected at altitudes between 3,000 and 10,000ft (900m and 3,000m).
Over a wide operational area, near real-time synoptic surface current data are provided, while fine resolution is available for assessing smaller scale current features.
The data can be used in combination with satellite, numerical model and in situ measurements, offering better understanding of offshore current features and enhancing operational planning. Information can also support the calibration and validation of predictive models.
The collection system - comprising two 11-megapixel panchromatic digital cameras and an inertial navigation system - can be quickly installed on any survey aircraft with a 19-inch photogrammetric hole. Trials were successfully conducted in October, 2012 using a twin-engine aircraft.
Preferred operating altitudes and weather impacts, including cloud levels, were assessed and the trials successfully demonstrated system capability with stationary measurement infrastructure in the Gulf of Mexico.
In addition to significant cost savings, the key advantages of ROCIS over existing measurement techniques include wider daily coverage, reduced data collection periods, rapid mobilisation and better measurement resolution.
Unlike vessel-based techniques, as the data are collected in the top five metres of the water column, the system measures the strongest currents.
Furgo GEOS says offshore oil and gas operators are set to benefit from ROCIS, utilising the system’s accurate information to mitigate against the impact of ocean currents on exploration, development and production activities. Other applications of the airborne system include oil spill events, where the detailed, wide-area information can be used for response operations and for validation of oil spill models. Search and rescue operations could use current mapping and information of surface drift patterns to aid emergency responders.
“ROCIS will significantly improve operational awareness of surface currents in key oil and gas exploration areas, especially for operators in frontier areas where limited current data exists,” explained Jan van Smirren, President of Fugro GEOS Inc. “The system will also provide data to support more accurate ocean forecast models, improve oil spill response measures and enhance offshore safety.”
Fugro will present an introduction to ROCIS at a technical session on 8th May during this year’s Offshore Technology Conference which takes place in Houston, TX, USA (www.otcnet.org). Registered attendees will have the opportunity to learn more about the science behind this innovative system, together with examples of trial data from the Gulf of Mexico. For further information and to register for the presentation, contact Regan Burford: rburford@fugro.com.
Source: Offshore Shipping Online
Photo courtesy of Ha-Wee via Flickr (CC BY 2.0)
