Compliance with the accuracy standard was ensured by the surveying of ten (10) GPS ground control points. The following checks were performed:
1. The ground control and airborne GPS/INS data stream were validated through an aerotriangulation bundle adjustment using Inpho Systems (Trimble) software. The residuals of the adjustment met the required standards with the results fully outlined in an AT report.
2. Digital orthoimagery was validated through a visual inspection of control points, edge matching, and general image quality.
Orthoimages are visually inspected for completeness to ensure that no gaps or image misplacements exist within and between adjacent images. These images are derived by mosaicking multiple images to ensure complete coverage of the project area.
The following methods were used to ensure image quality:
1. Use of ten (10) photo identifiable ground control during image acquisition.
2. Use of GPS/INS during image acquisition.
3. Checking of controls against ortho product.
4. Post ortho accuracy approval checks for overall image quality (tone, color balance, etc.).
Source_Information:
Source_Citation:
Citation_Information:
Originator: Kucera International Inc.
Publication_Date: Unpublished material
Title: Aerial imagery
Edition: 1.0
Geospatial_Data_Presentation_Form: raster digital data
Publication_Information:
Publication_Place: None
Publisher: None
Source_Scale_Denominator: 1200
Type_of_Source_Media: disc
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 20220313
Source_Currentness_Reference: Ground condition
Source_Citation_Abbreviation: IMG
Source_Contribution:
The aerial imagery was captured with a Vexcel UltraCam Eagle (UCEagle) large format digital aerial camera. Flight altitude was approximately 9600' MSL. The UCEagle uses an image frame based method of data collection with multiple, precisely registered CCDs collecting nadir oriented images along planned flight lines. Each CCD array collects data in one of the pan, red, green, blue or NIR spectral bands. This results in one image per frame CCD. Simultaneously with image capture, position and orientation information is collected with a Novatel SPAN GPS/INS system. The aerial images and GPS/INS data are post processed on the ground to produce color, color infrared or black and white digital images used for softcopy aerotriangulation, DEM generation, mapping and orthoimage production. Aerotriangulation refines the exterior orientation parameters (X, Y, Z, Omega, Phi, Kappa) of the recorded GPS/INS orientations.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Kucera International Inc.
Publication_Date: Unpublished material
Title: Ground control
Edition: 1.0
Geospatial_Data_Presentation_Form: Tabular digital data
Publication_Information:
Publication_Place: None
Publisher: None
Type_of_Source_Media: disc
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2022
Source_Currentness_Reference: Ground condition
Source_Citation_Abbreviation: CONT
Source_Contribution:
Image identifiable ground control were used to create a digital control file and control report as well as QC check of ortho accuracy. Predefined and surveyed points visible in the imagery and within the Town are selected. These points along with their precise coordinates are used in the aerotriangulation (AT) process and to check the horizontal accuracy of the resulting orthoimages.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Kucera International Inc.
Publication_Date: 2022
Title: Digital elevation model
Edition: 1.0
Geospatial_Data_Presentation_Form: Raster digital data
Publication_Information:
Publication_Place: Unknown
Publisher: Unknown
Type_of_Source_Media: disc
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2022
Source_Currentness_Reference: Ground condition
Source_Citation_Abbreviation: DEM
Source_Contribution:
The captured lidar was used to create a DEM to support the orthorectification. The lidar DEM was post-processed to a bare earth surface and exported as a GeoTIFF data set.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Kucera International Inc.
Publication_Date: Unknown
Title: Tile definition
Edition: 1.0
Geospatial_Data_Presentation_Form: Vector digital data
Publication_Information:
Publication_Place: Unknown
Publisher: Unknown
Type_of_Source_Media: disc
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2022
Source_Currentness_Reference: Ground condition
Source_Citation_Abbreviation: TLDEF
Source_Contribution:
The tile definition is used to cut orthorectified imagery into manageable, usable images. Each tile is 4900' X 4900'.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Kucera International Inc.
Publication_Date: Unpublished material
Title: Orthorectified imagery
Edition: 1.0
Geospatial_Data_Presentation_Form: raster digital data
Publication_Information:
Publication_Place: None
Publisher: None
Source_Scale_Denominator: 1200
Type_of_Source_Media: disc
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2022
Source_Currentness_Reference: Ground condition
Source_Citation_Abbreviation: OIMG1
Source_Contribution:
This first level of orthorectified images are the product of using the AT solution and the DEM in Inpho Orthomaster software. These large images still overlap with adjacent images. They have yet to be mosaiced into seamless tiled orthos.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Kucera International Inc.
Publication_Date: Unpublished material
Title: Tiled Orthoimage
Edition: 1.0
Geospatial_Data_Presentation_Form: raster digital data
Publication_Information:
Publication_Place: None
Publisher: None
Source_Scale_Denominator: 1200
Type_of_Source_Media: disc, DVD or online
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2022
Source_Currentness_Reference: Ground condition
Source_Citation_Abbreviation: OIMG2
Source_Contribution:
The tiled orthoimage is the result of mosaicking orthorectified imagery with Inpho Systems Orthovista software and using the tile definition to cut into seamless orthoimages. Orthovista merges all the input orthoimages and creates seamless color balanced image tiles based on the tile definition bounds.
Process_Step:
Process_Description:
At selected locations throughout the site, easily image identifiable points are selected and surveyed to augment the targeted control.
Source_Used_Citation_Abbreviation: None
Process_Date: 2022
Source_Produced_Citation_Abbreviation: CONT
Process_Step:
Process_Description:
New digital, color aerial imagery of the site is acquired using the UCEagle camera. Airborne GPS/IMU data is recorded along with the imagery
Source_Used_Citation_Abbreviation: None
Process_Date: 2022
Source_Produced_Citation_Abbreviation: IMG
Process_Step:
Process_Description:
Imagery and GPS/IMU data is downloaded from disc on the plane to disc on the ground. GPS/IMU mission data is processed together with simultaneously collected ground-based GPS base station data in forward and reverse directions. This precisely determines the aerial sensor's position and orientation in the terrain (project) coordinate system and allows for correct orientation of the imagery.
Source_Used_Citation_Abbreviation: IMG
Process_Date: 2022
Source_Produced_Citation_Abbreviation: GPS
Process_Step:
Process_Description:
Using the processed GPS/IMU data and correctly oriented imagery, a bundle adjustment is computed (AT) in Inpho Match-AT software.
Source_Used_Citation_Abbreviation: IMG, CONT, GPS
Process_Date: 2022
Source_Produced_Citation_Abbreviation: AT
Process_Step:
Process_Description:
Orthorectified imagery is produced using Inpho Systems (Trimble) Orthomaster software. The inputs are the digital aerial images, DEM and the aerotriangulation solution. The output images are overlapping orthorectified images that have yet to be mosaiced into seamless tiled orthos.
Source_Used_Citation_Abbreviation: IMG, DEM, AT
Process_Date: 2022
Source_Produced_Citation_Abbreviation: OIMG1
Process_Step:
Process_Description:
Orthorectified imagery is mosaiced, locally color-balanced and cut to the tile definition boundaries using Inpho OrthoVista software. The tiled orthos are checked for accuracy against the surveyed ground control before further image editing.
Source_Used_Citation_Abbreviation: OIMG1, CONT, TLDEF
Process_Date: 2022
Source_Produced_Citation_Abbreviation: OIMG2
Process_Step:
Process_Description:
Tiled orthoimages then go through a rigorous manual QC process to evaluate for remaining hotspots (sun reflectance over water), tone quality, color balance and the feathering area between flightlines. Any imperfections at this point are manually edited. If necessary, the tiled images are then converted to required format. All images are either recorded on DVD, transferred to HD, or posted on FTP for client access.
Source_Used_Citation_Abbreviation: OIMG2
Process_Date: 2022
Source_Produced_Citation_Abbreviation: OIMG2