| Identifier | 2021-607-FA | ||||||||
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| Also known as | SQUID5 system testing Tahoe Reef | ||||||||
| Purpose | Field testing of modifications/updates to the SQUID-5 underwater structure from motion mapping vehicle | ||||||||
| Location | Lake Tahoe, CA near Tahoe City | ||||||||
| Summary | Successfully collected high resolution lakebed imagery and associated navigation for processing with Structure from Motion (SfM) software. | ||||||||
| Info derived | Lake bed elevation and orthoimagery | ||||||||
| Comments | Entries for this field activity are based on entries from Field Activity 2020-634-FA | ||||||||
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| Vehicles | MarFac; Chevy 9 pass. van - green G42-0422G
MarFac; Expedition G62-3094P
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| Marine operations | Yes |
| Organization |
2885 Mission Street
Santa Cruz, CA95060
(831) 460-7401
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| Principal investigators | Gerald Hatcher | ||
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| Affiliate principal | Brant Allen, Field Lab Director and Boat Captain. UC Davis. S. Geoffrey Schladow, PhD, UC Davis |
| Data category: | Location-Elevation, Imagery |
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| Data type: | Navigation, Photo |
| Equipment | Usage description | Data types | Datasets |
|---|---|---|---|
| Trimble R7 GPS receiver | Benchmarks, LIDAR, Navigation, Profiles, Transects | (no data reported) | |
| SQUID-5 | Photo | 5 |
| Dataset name | Equipment | Description | Dataset contact |
|---|---|---|---|
| Bathymetric digital elevation model (DEM) of Lake Tahoe near Dollar Point | SQUID-5 | Underwater images collected near Dollar Point in Lake Tahoe, California, were processed using Structure-from-Motion (SfM) photogrammetry techniques into a classified 3D point cloud. The DEM was derived in Metashape (ver. 1.6.4) from the point cloud, but it excludes the 'high noise' class. The DEM data were output as a geoTIFF raster at 25-mm resolution. | Jonathan Warrick |
| GNSS locations of lakebed images collected near Dollar Point, Lake Tahoe, CA, March 10 and 11, 2021 | SQUID-5 | This text file (2021-607-FA_Image_Locations.txt) provides the GNSS antenna location for underwater images collected near Dollar Point, Lake Tahoe, CA, using a recently developed towed-surface vehicle with multiple downward-looking underwater cameras. The GNSS antenna location for the time of each image capture is presented with greater precision than is stored in the individual image's EXIF header due to decimal place limitations of the EXIF format. | Gerald Hatcher |
| Orthoimagery of Lake Tahoe near Dollar Point | SQUID-5 | Lakebed orthoimagery was developed from underwater images collected near Dollar Point in Lake Tahoe, California, and processed using Structure-from-Motion (SfM) photogrammetry techniques. The orthoimages were developed using both image-mosaic and image-averaging methods, which were then output as 5-mm resolution rasters. In general, the "Mosaic" product is somewhat sharper in resolution but will include some distinct seam lines and noticeable differences in image quality across the image. The "Average" product, in contrast, is more uniform in color and quality but blurrier overall. | Jonathan Warrick |
| Overlapping lakebed images collected near Dollar Point, Lake Tahoe, CA, March 10 and 11, 2021 | SQUID-5 | Underwater images were collected near Dollar Point, Lake Tahoe, CA, using a recently developed towed-surface vehicle with multiple downward-looking underwater cameras. The images are organized in zipped files grouped by survey line. The SQUID-5 system records images as TIFF (.tif) format to maintain the highest resolution and bit depth. Each image includes EXIF metadata, containing GNSS date, time, and latitude and longitude of the GNSS antenna mounted on the towed surface vehicle, copyright, keywords, and other fields. | Gerald Hatcher |
| Point cloud data of Lake Tahoe near Dollar Point | SQUID-5 | Three-dimensional point clouds (LAZ format) were developed from underwater images collected near Dollar Point in Lake Tahoe, California, and processed using Structure-from-Motion (SfM) photogrammetry techniques. Point cloud data include x,y,z positions, RGB colors, Metashape-computed confidence values, and a two-class classification ('unclassified' and 'high noise') derived from the confidence values. | Jonathan Warrick |
Hatcher, G.A.; Warrick, J.A.; Kranenburg, C.J.; Dal Ferro, P., 2021, Overlapping lakebed images and associated GNSS locations acquired near Dollar Point, Lake Tahoe, CA, March 2021: , https://doi.org/10.5066/P9V44ZYS.
Warrick, J.A.; Hatcher, G.A.; and Kranenburg, C.J., 2021, Point clouds, bathymetric maps, and orthoimagery generated from overlapping lakebed images acquired with the SQUID-5 system near Dollar Point, Lake Tahoe, CA, March 2021: , https://doi.org/10.5066/P9934I6U.
