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This portion of the data release presents a bathymetric point cloud from an unoccupied aerial system (UAS) survey of the coral reef off Waiakane, Molokai, Hawaii, on 24 June 2018. The point cloud has been corrected for the effects of refraction using the techniques described in Dietrich (2017a). The point cloud was created from structure-from-motion (SfM) processing of aerial imagery collected using a UAS with a Ricoh GR II digital camera fitted with a circular polarizing filter. During the survey, a pressure sensor was deployed in the survey area to gain an accurate measurement of the water surface elevation (WSE). After a preliminary dense point cloud was derived from SfM processing, the WSE was used to calculate...
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This portion of the data release presents a bathymetric digital surface model (DSM) from an unoccupied aerial system (UAS) survey of the coral reef off Waiakane, Molokai, Hawaii, on 24 June 2018. The DSM has a horizontal resolution of 10 centimeters per pixel and has been corrected for the effects of refraction using the techniques described in Dietrich (2017a). The DSM was created from structure-from-motion (SfM) processing of aerial imagery collected using a UAS with a Ricoh GR II digital camera fitted with a circular polarizing filter. During the survey, a pressure sensor was deployed in the survey area to derive an accurate measurement of the mean water surface elevation (WSE). After a preliminary dense point...
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OpenFOAM Computational Fluid Dynamics (CFD) models were developed to simulate wave energy dissipation across natural rough reef surfaces on the reef flat off Waiakane, Molokai, Hawaii, to understand this process in the context of reef restoration design. A total of 140 models were developed (70 per low- and 70 per high-bed-relief domains). Models were calibrated and validated with oceanographic datasets collected in 2018. This data release presents the 140 model scenarios that can be readily input into OpenFOAM to recreate the results, in addition to a csv file indicating the parameters used for each model scenario. These model data accompany Norris and others (2023) OpenFOAM Computational Fluid Dynamics (CFD) models...
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Time series data of water surface elevation, wave height, and water column currents and temperature were acquired at seven locations for 86 days off of Waiakane on the south coast of the island of Molokai, Hawaii, in support of a study on the coastal circulation patterns and the transformation of surface waves over the coral reefs.
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The lack of geographic and thematic maps of coral reefs limits our understanding of reefs and our ability to assess change. The U.S. Geological Survey (USGS) has the capability to compile digital image mosaics that are useful for creating detailed map products. Image maps covering the shallow near-shore coastal waters have been produced for several of the main Hawaiian Islands, including Hawai‘i, Maui, Moloka‘i, and O‘ahu and are presented in JPEG2000 (.jp2) format. The digital-image mosaics were generated by first scanning historical aerial photographs. At the time, available satellite image resolutions were not acceptable and the aerial photographs used were the best option. The individually scanned digital...
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This portion of the data release presents a high-resolution orthomosaic image of the coral reef off Waiakane, Molokai, Hawaii. The orthomosaic has a resolution of 2.5 centimeters (cm) per pixel and was derived from structure-from-motion (SfM) processing of aerial imagery collected with an unoccupied aerial system (UAS) on 24 June 2018. The raw imagery used to create the orthomosaic was acquired using a UAS fitted with a Ricoh GR II digital camera featuring a global shutter. The UAS was flown on pre-programmed autonomous flight lines spaced to provide approximately 75 percent overlap between images from adjacent lines. The UAS was flown at an approximate altitude of 100 meters above ground level (AGL), resulting...
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This portion of the data release presents raw aerial imagery collected during an unoccupied aerial system (UAS) survey of the coral reef off Waiakane, Molokai, Hawaii, on 24 June 2018. The imagery was acquired using a Department of Interior-owned 3DR Solo quadcopter fitted with a Ricoh GR II digital camera featuring a global shutter. The camera was mounted in a nadir orientation using a fixed mount. Before each flight, the camera’s digital ISO, aperture, and shutter speed were adjusted for ambient light conditions. The UAS was flown on pre-programmed autonomous flight lines spaced to provide approximately 75 percent overlap between images from adjacent lines. The UAS was flown at an approximate altitude of 100 meters...
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3D bathymetric surfaces of low- and high-relief sites from the coral reef flat off Waiakane, Molokai, were created using structure-from-motion (SfM) techniques. The two study sites are located approximately 640 m from shore and approximately 20 m apart in the alongshore direction. At each site, an approximate 12-meter diameter area was imaged in three passes by a swimmer using a handheld digital camera. These images were fed into Structure-from-Motion (SfM) software to produce high-resolution (fine-scale), accurate, and precise topographic point clouds with sub-centimeter accuracy for both the low- and high-relief sites. In addition, a subset of a previously published (Logan and Storlazzi, 2022), coarser-scale,...
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This portion of the data release presents the locations of the temporary ground control points (GCPs) used for the structure-from-motion (SfM) processing of the imagery collected during an unoccupied aerial system (UAS) survey of the coral reef off Waiakane, Molokai, Hawaii, on 24 June 2018. Twenty temporary ground control points (GCPs) were distributed throughout the survey area to establish survey control. The GCPs consisted of: nine submerged targets consisting of small (80 centimeter X 80 centimeter) square tarps with black-and-white cross patterns anchored to the shallow (less than 1.5 meters deep) seafloor using 0.9 kilogram fishing weights; nine sub-aerial targets consisting of orange plastic five-gallon...
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Time series data of water surface elevation, wave height, and water column currents and temperature were acquired at seven locations for 86 days off of Waiakane on the south coast of the island of Molokai, Hawaii, in support of a study on the coastal circulation patterns and the transformation of surface waves over the coral reefs. The relative placement of sensors on the reef were as follows: MKK18C01 – offshore MKK18C02 and MKK18C09 – fore reef MKK18C18 – reef crest MKK18C20 – outer reef flat MKK18C22 – middle reef flat MKK18C22 – inner reef flat


    map background search result map search result map Island of Moloka‘i Time-series oceanographic data of currents and waves from bottom-mounted instrument packages off Waiakane, Molokai, HI, 2018 Waiakane, Molokai, Hawaiian Islands, wave and water level data, 2018 Aerial imagery from the UAS survey of the coral reef off Waiakane, Molokai, Hawaii, 24 June 2018 Orthomosaic imagery from the UAS survey of the coral reef off Waiakane, Molokai, Hawaii, 24 June 2018 Refraction-corrected bathymetric digital surface model (DSM) from the UAS survey of the coral reef off Waiakane, Molokai, Hawaii, 24 June 2018 Refraction-corrected bathymetric point cloud from the UAS survey of the coral reef off Waiakane, Molokai, Hawaii, 24 June 2018 Ground control point locations for the UAS survey of the coral reef off Waiakane, Molokai, Hawaii, 24 June 2018 3D bathymetric surfaces of low- and high-relief sites from the coral reef flat off Waiakane, Molokai Aerial imagery from the UAS survey of the coral reef off Waiakane, Molokai, Hawaii, 24 June 2018 Orthomosaic imagery from the UAS survey of the coral reef off Waiakane, Molokai, Hawaii, 24 June 2018 Refraction-corrected bathymetric digital surface model (DSM) from the UAS survey of the coral reef off Waiakane, Molokai, Hawaii, 24 June 2018 Refraction-corrected bathymetric point cloud from the UAS survey of the coral reef off Waiakane, Molokai, Hawaii, 24 June 2018 Ground control point locations for the UAS survey of the coral reef off Waiakane, Molokai, Hawaii, 24 June 2018 Time-series oceanographic data of currents and waves from bottom-mounted instrument packages off Waiakane, Molokai, HI, 2018 Island of Moloka‘i