Sodus North digital elevation model (DEM) from low-altitude aerial imagery from unmanned aerial systems (UAS) flights over of the Lake Ontario shoreline in the vicinity of Sodus Bay, New York in July 2017 (32-bit floating point GeoTIFF image)

Metadata also available as - [Questions & Answers] - [Parseable text] - [XML]

Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator: U.S. Geological Survey
Publication_Date: 2018
Title:
Sodus North digital elevation model (DEM) from low-altitude aerial imagery from unmanned aerial systems (UAS) flights over of the Lake Ontario shoreline in the vicinity of Sodus Bay, New York in July 2017 (32-bit floating point GeoTIFF image)
Edition: 1.0
Geospatial_Data_Presentation_Form: raster digital data
Series_Information:
Series_Name: data release
Issue_Identification: DOI:10.5066/P9XQYCD0
Publication_Information:
Publication_Place: Woods Hole Coastal and Marine Science Center, Woods Hole, MA
Publisher: U.S. Geological Survey, Coastal and Marine Geology Program
Online_Linkage: https://doi.org/10.5066/P9XQYCD0
Online_Linkage: Larger_Work_Citation:
Citation_Information:
Originator: Christopher R. Sherwood
Originator: Sandra M. Brosnahan
Originator: Seth D. Ackerman
Originator: Jonathan Borden
Originator: Ellyn T. Montgomery
Originator: Elizabeth A. Pendleton
Originator: Emily J. Sturdivant
Publication_Date: 2018
Title:
Aerial imagery and photogrammetric products from unmanned aerial systems (UAS) flights over the Lake Ontario shoreline at Sodus Bay, New York, July 12 to 14, 2017
Edition: 1.0
Series_Information:
Series_Name: data release
Issue_Identification: DOI:10.5066/P9XQYCD0
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Other_Citation_Details:
Suggested citation: Sherwood, C.R., Brosnahan, S.M., Ackerman, S.D., Borden, Jonathan, Montgomery, E.T., Pendleton, E.A., and Sturdivant, E.J., 2018, Aerial imagery and photogrammetric products from unmanned aerial systems (UAS) flights over the Lake Ontario shoreline at Sodus Bay, New York, July 12 to 14, 2017: U.S. Geological Survey data release, https://doi.org/10.5066/P9XQYCD0.
Online_Linkage: https://doi.org/10.5066/P9XQYCD0
Online_Linkage:
Description:
Abstract:
Low-altitude (80-100 meters above ground level) digital images were obtained from a camera mounted on a 3DR Solo quadcopter, a small unmanned aerial system (UAS), along the Lake Ontario shoreline in New York during July 2017. These data were collected to document and monitor effects of high lake levels, including shoreline erosion, inundation, and property damage in the vicinity of Sodus Bay, New York. This data release includes images tagged with locations determined from the UAS GPS; tables with updated estimates of camera positions and attitudes based on the photogrammetric reconstruction; tables listing locations of the base stations, ground control points, and transect points; geolocated, RGB-colored point clouds; orthomosaic images; and digital elevation models for each of the survey regions. Collection of these data was supported by the Federal Emergency Management Agency, the State of New York Departments of State and Environmental Conservation, and the USGS Coastal and Marine Geology Program and was conducted under USGS field activity number 2017-042-FA.
Purpose:
The gridded DEM surface estimates the elevation of the land surface at mid-day low-tide on 13 July, 2017 in the Sodus North study area. It was created to demonstrate the use of structure-from-motion (SfM) for shoreline research and to provide a means to measure the accuracy of the elevation measured through SfM photogrammetry. It is released to provide an elevation dataset that is more accessible than the LAZ elevation point cloud for the general user.
Supplemental_Information:
For more information about this field activity, see https://cmgds.marine.usgs.gov/fan_info.php?fan=2017-042-FA.
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 20170713
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -76.986648
East_Bounding_Coordinate: -76.966694
North_Bounding_Coordinate: 43.277607
South_Bounding_Coordinate: 43.270506
Keywords:
Theme:
Theme_Keyword_Thesaurus: USGS Metadata Identifier
Theme_Keyword: USGS:5b1eeb73e4b092d965254a91
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: U.S. Geological Survey
Theme_Keyword: USGS
Theme_Keyword: Coastal and Marine Geology Program
Theme_Keyword: CMGP
Theme_Keyword: Woods Hole Coastal and Marine Science Center
Theme_Keyword: WHCMSC
Theme_Keyword: State of New York Department of State
Theme_Keyword: State of New York Department of Environmental Conservation
Theme_Keyword: Federal Emergency Management Agency
Theme_Keyword: shoreline
Theme_Keyword: lake level
Theme_Keyword: 3DR Solo quadcopter
Theme_Keyword: Ricoh GRII
Theme_Keyword: low-altitude aerial imagery
Theme_Keyword: aerial imagery
Theme_Keyword: shoreline photographs
Theme_Keyword: photographs
Theme_Keyword: photos
Theme_Keyword: UAS
Theme_Keyword: Unmanned aerial system
Theme_Keyword: lakeshore
Theme_Keyword: digital elevation model
Theme_Keyword: DEM
Theme_Keyword: GeoTIFF
Theme_Keyword: raster
Theme_Keyword: field activity number 2017-042-FA
Theme:
Theme_Keyword_Thesaurus: USGS Thesaurus
Theme_Keyword: remote sensing
Theme_Keyword: topography
Theme_Keyword: digital elevation models
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: geoscientificInformation
Theme_Keyword: inlandWaters
Theme_Keyword: location
Theme_Keyword: elevation
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: USA
Place_Keyword: Great Lakes
Place_Keyword: New York
Place_Keyword: Lake Ontario
Place_Keyword: Sodus, NY
Place_Keyword: Sodus Point
Place_Keyword: Sodus Bay
Place_Keyword: Crescent Bar
Place_Keyword: Sodus Point
Access_Constraints: none
Use_Constraints:
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: Sandra Brosnahan
Contact_Position: Physical Scientist
Contact_Address:
Address_Type: mailing and physical address
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: Massachusetts
Postal_Code: 02543-1598
Contact_Voice_Telephone: 508-548-8700 x2265
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: sbrosnahan@usgs.gov
Browse_Graphic:
Browse_Graphic_File_Name: Browse_Graphic_File_Description:
Browse graphic of a portion of the DEM generated from photogrammetry and low-altitude aerial images obtained with unmanned aerial systems (UAS).
Browse_Graphic_File_Type: JPEG
Data_Quality_Information:
Logical_Consistency_Report:
All data were handled in a consistent manner. Photoscan software determines the photos used in the construction of the products (Point Cloud, DEM and Orthomosaic) based on the ability to align the photo and the usability of valid tie points within an image, and some photos of the take-off and landing were omitted by the processor during the import data phase. A tie point represents a point that the software determine to be common from one photo to the next. The camera locations CSV file in the larger work citation indicates which photos were used to create the final products. The final point cloud used to construct this dataset was checked for accuracy by rotating the point cloud to view from multiple angles to ensure that obvious spurious points do not cause artifacts in the derivative products (DEM and Orthomosaic).
Completeness_Report:
This DEM was created from the filtered tie-points of the dense point cloud using the Agisoft Photoscan Professional (v. 1.3.2) photogrammetry software. Through a standardized filtering process, spurious points from the dense point cloud were eliminated and the remaining point cloud was used to generate a digital elevation model. The completed Photoscan project for Sodus North, from which this DEM was created, used 1484 of the original 1537 images and contained more than 204 million points. The unedited point cloud and the orthomosaic are available in the larger work citation.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Horizontal positions of individual points for the DEM were calculated by photogrammetric software and ground control points. There are several sources of potential error that affect the horizontal accuracy:
1. The horizontal error estimate provided by Agisoft Photoscan for the Charles Point project as a result of alignment, optimization, and ground control processing procedures is 4.42 cm. This value is an RMS estimate of positional error at discrete locations within the orthomosaic.
2. Ground control points were collected using a Spectra model SP80 GNSS receiver set to record XY locations with the national adjustment of 2011 (NAD83(2011) UTM zone 18N EPSG::6347), which differs from the Photoscan project coordinate system (NAD83/UTM zone 18N (EPSG::26918)). This difference may introduce an average additional 0.9 cm horizontally at the 95% confidence level according to the National Geodetic Survey (https://www.ngs.noaa.gov/web/surveys/NA2011/).
3. Additionally, an assessment of repeated survey sites including transect points and ground control points, using the same equipment by the USGS Aerial Imagery and Mapping (AIM) group estimates an accuracy of the ground control point locations of 1.76 cm (horizontal) and 0.54 cm (vertical).
The combination of the potential horizontal error is on the order of 6.9 cm for the Charles Point products. Although some portions of the map may contain much larger errors, greater than 2 m horizontally, especially along the boundary of the project that are far from a ground control point, and across water bodies. The horizontal coordinate system for the Charles Point Point Cloud, DEM and Orthomosaic is NAD83/UTM zone 18N (EPSG::26918).

It is also important to note: The UAS image locations are derived from a mRo GPS (u-Blox Neo-M8N / 3DR SOLO Upgrade), located on the UAS, which receives signals from GPS and GLONASS satellites in WGS84 (G1150) EPSG::7660. This location information is used by the Photoscan software to help with the initial alignment, however after photo alignment, these location data have no bearing on the project or the derivative product. Therefore the positional accuracy and potential errors of the GPS data attached to the input photographs is not propagated to the Photoscan project and therefore does not contribute to the overall horizontal accuracy of the products (Point Cloud, DEM and Orthomosaic).
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
Vertical positions of individual points for the point cloud were calculated by photogrammetric software and ground control points. There are several sources of potential error that affect the vertical accuracy:
1. The vertical error estimate provided by Agisoft Photoscan for the Charles Point project as a result of alignment, optimization, and ground control processing procedures is 11.28 cm. This value is an RMS estimate of positional error at discrete locations within the orthomosaic.
2. Ground control points were collected using a Spectra model SP80 GNSS receiver that was receiving real-time differential corrections from a GNSS base station established in Sodus Bay NY. The Z heights were reference to the NAVD88 vertical datum. An assessment of repeated survey sites using the same equipment by the USGS Aerial Imagery and Mapping group estimates a potential accuracy error of the ground control point locations of 1.76 cm (horizontally) and 0.54 cm (vertically).
The combination of the potential vertical error is on the order of 2.0 cm for the photogrammetric products. Although some portions of the map may contain much larger errors, greater than 20 m vertically, especially along the boundary of the project that are far from a ground control point, and across water bodies. The vertical datum for the Charles Point Point Cloud, DEM and Orthomosaic is NAVD88 (meters).
It is also important to note: The UAS image locations are derived from a mRo GPS (u-Blox Neo-M8N / 3DR SOLO Upgrade), located on the UAS, which receives signals from GPS and GLONASS satellites in WGS84 (G1150) EPSG::7660. This location information is used by the Photoscan software to help with the initial alignment, however after photo alignment, these location data have no bearing on the project or the derivative product. Therefore the positional accuracy and potential errors of the GPS data attached to the input photographs is not propagated to the Photoscan project and therefore does not contribute to the overall vertical accuracy of the products (Point Cloud and DEM).
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: U.S. Geological Survey
Publication_Date: unpublished material
Title: Field geotagged aerial imagery
Type_of_Source_Media: raster digital images
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20170712
Ending_Date: 20170714
Source_Currentness_Reference:
ground condition; images were obtained between 20170712 and 20170714.
Source_Citation_Abbreviation: geotagged aerial digital images
Source_Contribution:
These are the images geotagged in the field using Mission Planner Software (version 1.3.49) and used to produce the subsequent photogrammetric products. The images available from the larger work citation of this data release are the same images, however they were renamed and geotagged using exiftools (version 10.93).
Source_Information:
Source_Citation:
Citation_Information:
Originator: U.S. Geological Survey
Publication_Date: 2018
Title:
Ground control point and transect locations associated with images collected during unmanned aerial systems (UAS) flights over The Lake Ontario shoreline in the vicinity of Sodus Bay, New York in July 2017
Other_Citation_Details:
available from the Larger Work citation of this dataset (Suggested citation: Sherwood, C.R., Brosnahan, S.M., Ackerman, S.D., Borden, Jonathan, Montgomery, E.T., Pendleton, E.A., and Sturdivant, E.J., 2018, Aerial imagery and photogrammetric products from unmanned aerial systems (UAS) flights over the Lake Ontario shoreline at Sodus Bay, New York, July 12 to 14, 2017: U.S. Geological Survey data release, https://doi.org/10.5066/P9XQYCD0.)
Type_of_Source_Media: text data files
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20170712
Ending_Date: 20170714
Source_Currentness_Reference:
ground condition; ground control points were obtained between 20170712 and 20170714.
Source_Citation_Abbreviation: GCPs
Source_Contribution:
The ground control points (GCPs; not transect points -- see metadata for more information) were used to geolocate the photogrammetric products.
Process_Step:
Process_Description:
Digital elevation models (DEM) for the Lake Ontario projects were constructed using photogrammetry software (Agisoft Photoscan Professional v. 1.3.2) and digital images taken approximately 80 and 100 m above the ground on July 10 - 14, 2017, with a Ricoh GRII digital camera mounted in a 3DR Solo quadcopter operated the U.S. Geological Survey. This DEM is the product from one of several photogrammetry projects from field activity 2017-042-FA. Four projects were used for flights in the vicinity of Sodus Bay on July 12, 13, and 14, 2017 (Lake Bluffs, Charles Point, Sodus North, and Greig Street). The projects combined images with ground control points to produce geolocated, colored (red-green-blue schema) point clouds. This DEM, for the Greig Street project, was created using a standard processing flow as described in the processing step below.
Process_Date: 201709
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
U.S. Geological Survey, Woods Hole Coastal and Marine Science Center
Contact_Person: Christopher R. Sherwood
Contact_Position: Research Oceanographer
Contact_Address:
Address_Type: mailing and physical address
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: Massachusetts
Postal_Code: 02543
Country: U.S.A.
Contact_Voice_Telephone: 508-548-8700 x2269
Contact_Facsimile_Telephone: 508 457 2310
Contact_Electronic_Mail_Address: csherwood@usgs.gov
Process_Step:
Process_Description:
The following steps make up the processing flow for creating digital elevation models from UAS flights:
1. Geotagged images (see source citation) containing useful imagery from the survey area were imported into Agisoft Photoscan Professional v. 1.3.2 software using the “Add photos…” tool. Photos taken before and immediately after takeoff, photos taken immediately prior to and after landing, and photos with 100% water were not loaded into the project. Project coordinate system is set to EPSG::7660 WGS84 (G1150) geocentric coordinate system.
2. Using ”Convert”, the coordinate system of the images (called “cameras” in Photoscan) was converted from native latitude/longitude WGS84 (G1150) coordinate system to meters in NAD83/UTM zone 18N (EPSG::26918).
3. The photos were processed through an initial alignment and optimization procedure using the following settings: Alignment - Accuracy: “High”; Pair selection: “Reference”; Key point limit: 80,000; Tie point limit; 0 (unlimited). Adaptive camera model fitting option was selected. Optimization - Lens-calibration parameters f, cx, cy, k1, k2, k3, p1, and p2 were included; b1, b2, and higher-order parameters k4, p3, and p4 were not.
4. The sparse point cloud (also known as tie points; created as a result of photo alignment and optimization) was edited using an iterative error-reduction procedure to filter the data. This was done in several iterations of a process called "Gradual Selection" to first to reduce reconstruction uncertainty (to a unitless value of 10) and then projection accuracy (to a weighted value of 3).
5. Ground control points were created by first letting the software automatically detect markers where it finds all of the 4-ft square black/white targets deployed (false targets that are sometimes detected were manually deleted). The automatically-generated marker labels were manually changed to match the names in the survey notes and GCP location files.
6. "Import markers” was used to load the GCP location files, which assigned coordinates (northing, easting, and elevation in UTM Zone 18 North meters in NAD83 and NAVD88 coordinate systems) from the location file to the detected markers. The locations of auto-detected markers were retained.
7. Another round of "Gradual Selection" was done to reduce the reprojection error (to a value of 0.3 pixels, unless more than 10% of the points would be removed).
8. A dense point cloud was then created with the parameters "High" quality and “Aggressive” depth filtering.
9. A DEM was created with Global Mapper (v. 19.0) using average binning method with a resolution of 0.05. Elevation points below 72.0 meters were filter out before gridding, and interpolation was set to 'loose' at '75'.
10. The DEM was exported in GeoTIFF format (Sodus_North_DEM_5cm.tif) along with a world file (tfw), then both were renamed to the AIM data release filenaming standard (e.g. 2017042FA_SodusNorth_DEM.tif).
Process_Date: 20170913
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
U.S. Geological Survey, Woods Hole Coastal and Marine Science Center
Contact_Person: Christopher R. Sherwood
Contact_Position: Research Oceanographer
Contact_Address:
Address_Type: mailing and physical address
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: Massachusetts
Postal_Code: 02543
Country: U.S.A.
Contact_Voice_Telephone: 508-548-8700 x2269
Contact_Facsimile_Telephone: 508 457 2310
Contact_Electronic_Mail_Address: csherwood@usgs.gov
Process_Step:
Process_Description:
Added keywords section with USGS persistent identifier as theme keyword.
Process_Date: 20200810
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Contact_Voice_Telephone: 508-548-8700 x2251
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: vatnipp@usgs.gov
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Pixel
Row_Count: 13360
Column_Count: 38480
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Map_Projection:
Map_Projection_Name: Universal Transverse Mercator
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.999600
Longitude_of_Central_Meridian: -75.00000
Latitude_of_Projection_Origin: 0.000
False_Easting: 500000.0000
False_Northing: 0.0000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 0.05
Ordinate_Resolution: 0.05
Planar_Distance_Units: meters
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257222101
Vertical_Coordinate_System_Definition:
Altitude_System_Definition:
Altitude_Datum_Name: North American Vertical Datum of 1988 (NAVD88)
Altitude_Resolution: 0.00001
Altitude_Distance_Units: meters
Altitude_Encoding_Method:
Explicit elevation coordinate included with horizontal coordinates
Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
There are no attributes associated with this GeoTIFF however the pixel values of the 32-bit image are elevation values as exported from Agisoft Photoscan. The "no data" value is set to -32767. Data values represent elevation in meters referenced to NAVD88. Note the full precision of the elevation as exported from the Agisoft Photoscan software is 0.00001 m although that is several orders of magnitude finer than the accuracy of the data. The elevation values range from 33.7 to 109.0 meters relative to NAVD88.
Entity_and_Attribute_Detail_Citation: U.S. Geological Survey
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey - ScienceBase
Contact_Address:
Address_Type: mailing and physical address
Address: Denver Federal Center, Building 810, Mail Stop 302
City: Denver
State_or_Province: CO
Postal_Code: 80225
Contact_Voice_Telephone: 1-888-275-8747
Contact_Electronic_Mail_Address: sciencebase@usgs.gov
Resource_Description:
This data release contains a DEM in 32-bit floating point GeoTIFF format (2017042FA_SodusNorth_DEM.tif), the world file (2017042FA_SodusNorth_DEM.tfw). FGDC CSDGM metadata (2017042FA_SodusNorth_DEM.xml) accompanies the data.
Distribution_Liability:
Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: GeoTIFF
Format_Version_Number: Agisoft Photoscan Professional v. 1.3.2 GeoTIFF
Format_Specification: 32-bit floating point GeoTIFF image
Format_Information_Content:
DEM in 32-bit floating point GeoTIFF image at 0.05 meter resolution, world file and the associated metadata.
Transfer_Size: 757
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information: Access_Instructions:
To download the data, it is recommended that you go to the page containing the data and take advantage of the large file handler. The first link is to the page containing the data. The second is a direct link to download all data available from the page as a zip file. And the final link is to the publication landing page.
Fees: none
Technical_Prerequisites:
To utilize these data an image processing or GIS software package capable of viewing a 32-bit Floating Point GeoTIFF image. Standard image viewing software cannot translate the elevation data from 32-bit floating point GeoTIFF image.
Metadata_Reference_Information:
Metadata_Date: 20200810
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: Sandra Brosnahan
Contact_Position: Physical Scientist
Contact_Address:
Address_Type: mailing and physical address
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: Massachusetts
Postal_Code: 02543-1598
Contact_Voice_Telephone: 508-548-8700 x2265
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: sbrosnahan@usgs.gov
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998

This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/SB_data_release/DR_P9XQYCD0/2017042FA_SodusNorth_DEM.html>
Generated by mp version 2.9.50 on Tue Sep 21 18:20:12 2021