AKA: SQUID5 system testing Tahoe Reef
Other ID: none
Status: Completed
Organization(s): USGS, Pacific Coastal and Marine Science Center
Funding Program(s): Other (Other)
Principal Investigator(s): Gerry Hatcher
Affiliate Investigator(s): Brant Allen, Field Lab Director and Boat Captain. UC Davis. S. Geoffrey Schladow, PhD, UC Davis
Information Specialist(s): Peter Dal Ferro
Data Type(s): Location-Elevation: Navigation, Imagery: Photo
Scientific Purpose/Goals: Field testing of modifications/updates to the SQUID-5 underwater structure from motion mapping vehicle
Vehicle(s): MarFac; Chevy 9 pass. van - green G42-0422G, MarFac; Expedition G62-3094P
Start Port/Location: Tahoe City, CA
End Port/Location: Tahoe City, CA
Start Date: 2021-03-08
End Date: 2021-03-12
Equipment Used: Trimble R7 GPS receiver, SQUID-5
Information to be Derived: Lake bed elevation and orthoimagery
Summary of Activity and Data Gathered: Successfully collected high resolution lakebed imagery and associated navigation for processing with Structure from Motion (SfM) software.
Staff:
Affiliate Staff:
Notes: Entries for this field activity are based on entries from Field Activity 2020-634-FA
Location:
Lake Tahoe, CA near Tahoe City
| Boundaries | |||
|---|---|---|---|
| North: 39.19346594 | South: 39.15642106 | West: -120.1521492 | East: -120.08022308 |
Platform(s):
 Boat |
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: U.S. Geological Survey data release, 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: U.S. Geological Survey data release, https://doi.org/10.5066/P9934I6U.
| Survey Equipment | Survey Info | Data Type(s) | Data Collected |
|---|---|---|---|
| Trimble R7 GPS receiver | --- | Benchmarks LIDAR Navigation Profiles Transects | |
| SQUID-5 | --- | Photo | GNSS locations of lakebed images collected near Dollar Point, Lake Tahoe, CA, March 10 and 11, 2021 (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.) Point cloud data of Lake Tahoe near Dollar Point (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.) Overlapping lakebed images collected near Dollar Point, Lake Tahoe, CA, March 10 and 11, 2021 (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.) Bathymetric digital elevation model (DEM) of Lake Tahoe near Dollar Point (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.) Orthoimagery of Lake Tahoe near Dollar Point (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.) |
