Mar 08

3D Mapping: Valuable By-product of LiDAR

DEM_Plan_Buildings_and_Veg

3D Feature extraction from LiDAR can provide municipalities with fresh perspectives on urban planning and help secure broad project support.

Oblique_AllThe traditional view of LiDAR as a tool to produce topographic contours for floodplain studies is being challenged by increasingly complex applications for feature extraction from this technology.  Today, instead of merely looking at the bare earth information, savvy LiDAR users look above the surface.  There is an incredible wealth Zoomed_Out_Ortho_and_Treesof information captured within these point clouds that provide 3-dimensional perspectives on our natural and urban landscapes.

To make the most of significant investments in LiDAR, many counties and municipalities are now seeking additional project stakeholders that can Zoomed_Out_Planbenefit from these projects.

The ability to capture 3D information in addition to surface models opens up many possibilities to secure support for the project from diverse municipal services: planning and zoning, public safety, parks and forestry, etc.  For example, a community that is using Zoomed_Out_Plan_and_TreesLiDAR to mitigate stormwater issues can offer 3D buildings to planners and electric distribution networks to public utilities.  Or, a county that is revising flood insurance rate maps may find project partners within parks and forestry departments to create forest canopy data.

To get the biggest bang out of LiDAR, it is important to consider what other potential applications may be supported by the project. The ability to extract detailed information above the bare earth can hinge on the specifications of the LiDAR mission such as raw point density and swath overlap.

Electric distribution network extracted from a LiDAR point cloud:

Wires5Wires4 Wires1

 

 

Feb 26

Ayres/SAA to Present at 2015 APA-WI Annual Planning Workshop

SAA’s Blake Theisen and Jason Krueger of Ayres Associates will present at the 2015 American Planning Association-Wisconsin Annual Planning Workshop at the Pfister Hotel in Milwaukee. The workshop this year focuses on the Tech Side of Planning. Blake and Jason will present their talk “GIS Data: Different Sources, Similar Environments – Aerial Imagery, LiDAR, 3D.”

The conference program is available here. You can register for the workshop and view the presentations on the APA-WI website.Register for the APA-WI Conference

Jan 07

LiDAR Video from NEON

Here’s a new video from National Ecological Observatory Network (NEON) that does a great job of describing basics of Lidar technology:

“How Does LiDAR Remote Sensing Work?”:

https://www.youtube.com/watch?v=EYbhNSUnIdU&feature=player_embedded

 

 

 

 

 

Dec 19

Found in Illinois, 2014 (Part III, History)

Approximately 4000 square miles of high resolution digital aerial imagery collected in Illinois by Ayres Associates in 2014.  Thank you to all of our friends for making this year a tremendous success!  Throughout the year we’ve collected snapshots of the unique cultural, historical, and natural sites in your communities and wanted to share them with everyone.

There is a lot of history to be found within the 4000 square miles of imagery we collected in Illinois this year.  Here are a couple of interesting sites from opposite sides of the State that we found extremely interesting and worth sharing.

 

Chanute Air Field

Chanute Air Force Base, near Rantoul, Illinois, was established in 1917 as a training facility for the Air Service shortly after the US entered WWI.  This base was an important training facility for pilots and support personnel during World War II and the Korean War. It is at this site that the famous 99th Pursuit Squadron, the Tuskegee Airmen, were activated.

Chanute_Field

Chanute_Field2

6-inch resolution orthoimagery collected by Ayres Associates for Champaign County in spring 2014, using an Intergraph DMCII 140 Digital Mapping Camera.

In the 1960’s Chanute became the principal training facility for the LGM-30 Minuteman intercontinental ballistic missile program.  The base was closed in 1993.  However, it is still operated as a museum and houses many historical aircraft and other exhibits:  http://www.aeromuseum.org

 Chanute_Air_Force_Base_-_1940s_postcard

 

Kaskaskia

Kaskaskia, located on the Mississippi River in Randolph County is one of the most historically significant French colonial towns and trading centers in Illinois.  While established on the east bank of the Mighty Mississippi, the Village found itself on the opposite bank when the River decided to move in 1881. While still part of Illinois, it is only reachable by land from Missouri. Kaskaskia

 6-inch resolution orthoimagery collected by Ayres Associates in spring 2014, using an UltraCAM Eagle.

Kaskaskia was the site of important battles of the French and Indian War and the American Revolution.  Fort Kaskaskia was destroyed by the British in 1763 and later seized by the Americans  in 1778, representing the western-most battle of the Revolution.  At its peak in the 1700’s, the Village was home to more than 7,000 residents.  The Village now consists of 14 persons, according to the 2010 census. It also served as the State’s first capital from 1818-19.  Read more about Kaskaskia’s fascinating history here: http://en.wikipedia.org/wiki/Kaskaskia,_Illinois

 

Kaskaskia2

The “Liberty Bell of the West” presented to the Catholic Church of Kaskaskia by French King Lois the XV, was rung on July 4, 1778 upon liberation of the Village from the British by American forces.

 

1024px-Kaskaskia_Bell_3321Image courtesy of author: Kbh3rd

(http://commons.wikimedia.org/wiki/File:Kaskaskia_Bell_3321.jpg)

 

 

 

Dec 14

Found in Illinois, 2014 (Part II, Architecture)

Approximately 4000 square miles of high resolution digital aerial imagery collected in Illinois by Ayres Associates in 2014.  Thank you to all of our friends for making this year a tremendous success!  Throughout the year we’ve collected snapshots of the unique cultural, historical, and natural sites in your communities and wanted to share them with everyone.

Robert_Allerton_ParkAllerton House, Piatt County, Illinois

Ayres Associates collected snap shots of unique architectural landmarks throughout the projects we flew in Illinois this past spring.  From large estates in the countryside to prairie style homes in the Chicago suburbs, Illinois provides a diverse range of important architectural wonders. Here’s a sampling:

Robert Allerton Park

allerton2

 

 

allertonRobert Allerton Park near Monticello in Piatt County, is a 1500 acre park and nature center. The former estate of Robert Allerton features the grand Allerton House (along with several other buildings), many elaborate gardens, and natural spaces. This imagery was captured for Piatt County as part of the Champaign County GIS Consortium (CCGISC).  6-inch resolution orthoimagery was prepared and tested using NSSDA procedure to confirm that it meets ASPRS Class 1 accuracy standards.  Photo  to the right is courtesy of: D. Finnigan http://commons.wikimedia.org/wiki/File:Allerton_House_and_Pond_at_Allerton_Park.jpg#filehistory

 

Oak Park & Frank Lloyd Wright

FLW_houses

In Oak Park, Illinois there are more Frank Lloyd Wright homes than you can shake a stick at.  In fact the Village boasts the largest collection FLW homes in the world. There are 14 FLW homes located in the quarter-square mile area shown in the image above.  This imagery was captured for the Village by Ayres Associates in the spring of 2014 and prepared as 3″ resolution digital orthoimagery.

Frank_Lloyd_Wright_Home_Studio
Frank Lloyd Wright Home Studio, photo courtesy of: Library of Congress, Prints & Photographs Division, ILL,16-OAKPA,5-2
Read more about Oak Park and the FLW Studio here:  http://en.wikipedia.org/wiki/Oak_Park,_Illinois
Oh yeah, and Ernest Hemingway’s birthplace home is also found in this same area of Oak Park: hemingways_birthplace_OP

Tinley Park Metra Station

Metra_station_TinleyPark3 The Metra Station in downtown Tinley Park’s historic district was honored in 2007 by the American Institute of Architects (AIA) as one of the 150 Great Places of Illinois. This 3″ resolution orthoimagery was captured by Ayres Associates for the GIS Consortium on behalf of the Village (www.gisconsortium.org).

Image [above] courtesy of Google Earth
Metra_station_TinleyPark4
Planimetric features of downtown Tinley Park compiled by Ayres Assocites for GIS geodatabase.

Dec 10

Found in Illinois, 2014 (Part I, Football)

Approximately 4000 square miles of high resolution digital aerial imagery collected in Illinois by Ayres Associates in 2014.  Thank you to all of our friends for making this year a tremendous success!  Throughout the year we’ve collected snapshots of the unique cultural, historical, and natural sites in your communities and wanted to share them with everyone.

Part I – Football in Illinois

UofI

Memorial Stadium: The Fighting Illini of the University of Illinois

Soon the high school championships, college bowl games, and professional football playoffs of the 2014 season will be behind us and we’ll be again looking at the empty stadiums and football fields in our communities for a few months.

Ayres Associates collected snap shots of several fields and stadiums throughout the projects we flew in Illinois this past spring… as they sat empty waiting for the fans.  As it turns out, there’s a lot of football fields within 4000 square miles!  Here’s a sampling:

(click on images below for enlargement).

 

The Wolves of Niles West HS – GIS Consortium (3″ Orthos)

Niles

 

 

 

 

 

 

 

The Spartans of Glenbrook HS (as seen in: Ferris Bueller’s Day Off & The Breakfast Club)

GIS Consortium (3″ orthos with 50′ scale planimetrics

Glenbrook_North_Spartans_Northbrook

 

The Bison of Buffalo Grove HS – GIS Consortium (3″ Orthos)

Buffalo_Grove_Bison1

 

The Thunderbolts of Andrew HS, Tinley Park – GIS Consortium

(3″ orthos, 50′ scale planimetrics, & 1′ contours, draped over a Lidar DEM)

andrews_tbolts_TP1 andrews_tbolts_TP2

 

 

 

 

 

 

 

The Yellow Jackets of Chester HS – Randolph County (3″ Orthos)

Chester_YellowjacketsChester_Yellowjackets_2

 

The Huskies of Oak Park River Forest HS – Oak Park (3″ Orthos)

Oak Park-River Forest Huskies-2

 

The Foxes of Yorkville HS – Kendall County (6″ Orthos)

Yorkville_foxes

 

The Grenadiers of Elk Grove HS – GIS Consortium (3″ Orthos)

Elk_Grove_Grenadiers

 

The Chargers of Centennial HS – Champaign County (6″ Orthos)

Centennial_HS_Chargers

 

The Warriors of Watseka HS – Iroquois County (6″ Orthos)

Watseka_Warriors

 

The Pirates of Cumberland HS – Cumberland County (6″ Orthos)

Cumberland_HS_Pirates

 

The Warriors of Willowbrook HS – GIS Consortium (3″ Orthos)

Willowbrook_warriors

 

 

The Lions of Cartersville HS – Williamson County (3″ Orthos)

cartersville_lions

 

The Bearcats of Miford-Cissna HS – Iroquois County (6″ Orthos)

Milford-Cissna_Park_Bearcats

 

The Reapers of Plano HS – Kendall County (6″ Orthos)

Reapers_Plano

 

 

Nov 04

Ayres Associates helping Menominee Tribal Enterprises track forest health

The Menominee Indian Tribe of Wisconsin realized long ago that their future depended on the forest. With lands totaling 235,000 acres, the Tribe began practicing forest management over 150 years ago and in 1908 created what is now known as Menominee Tribal Enterprises (MTE) to manage their lands.  To this day, forestry remains the backbone of its economy.

MTE_colorThe fungal disease oak wilt is a serious problem infecting the mature oak stands of the Menominee forest, posing significant potential impacts to the tribe’s economy.  In an effort to arrest the spread of the disease, MTE has a program prepared to rapidly deal with oak wilt pockets as soon as they are identified.  Given that Menominee has thousands of acres of oak trees, field surveys end up being very costly and time consuming.  By working together with Ayres Associates, MTE determined that aerial imagery can serve as an effective tool for quickly and efficiently surveying vast areas beyond what can be covered by a road-side study.

 

Forest health staff analyzes the imagery by overlaying known oak wilt pockets on top of recent imagery acquired in the late summer.  Any newly infected trees can be detected in the true-color images, appearing in shades of brown, while older (dead) oaks will be visible as ‘gray ghosts’.  When found, a staff member will place a point in the GIS database and upload the data to an ArcPad project on a data recorder.  Then a forester can conduct a visit to the site to determine whether or not the dead tree can be attributed to oak wilt.  All positively identified pockets are scheduled for treatment.

MTE_cirMTE is now implementing workflows to incorporate color infrared (CIR) imagery into their analysis. Using CIR imagery will make tree health even more apparent to foresters reviewing the data.  Using Ayres Associate’s calibrated multi-spectral photogrammetric cameras to collect and analyze digital CIR aerial imagery will add another effective tool to map assets, track change, and analyze systemic health patterns in the forest.

MTE’s primary mission is to provide for the Tribe while simultaneously planning for and maintaining a sustainable forest.  Over the course of decades, they have aggressively pushed advanced management techniques to provide sustained timber yields.  With the advancement of diseases like oak wilt and emerald ash borer, color and CIR aerial imagery have become an even more vital tool for cost effectively survey these essential lands.

 

Oct 22

Monitoring Landfills from Above

Constant monitoring and frequent measuring of landfill data is how landfill operators maintain safe, efficient and profitable functioning facilities.  Ayres Associates has provided geospatial services for numerous landfills across the country.  SevenMile_3D-5Recently, Cornerstone Environmental Group worked with Ayres to provide geospatial services for 21 active landfill sites in seven states. With the use of a Leica RCD30 digital aerial camera, the imagery was acquired and then utilized to create 2-foot interval topographic contours of the active sites.

There is a limited amount of time in which landfill sites can be flown, particularly in the Midwest.  The most viable flight time is in the early spring, when the ground is no longer snow-covered, but before the leaves have begun to appear on the trees.  After the initial aerial acquisition, fast turnaround on topographic mapping is critical for landfill decision makers, as their operational budgets cannot be finalized until after the flight and once the topographic data has been submitted for volumetric computations.

In addition to aerial-based topographic mapping for landfill volume calculations, waste collection companies benefit from a number of other geospatial services:

Up-to-date high-resolution orthoimagery is useful for making facility inventories. Because it’s rectified for real-world measurements, the imagery can serve as a tool for engineering-grade measurements. Planimetric mapping provides detailed data of ground features such as access roads, fence lines, building outlines, and monitoring devices.

Additionally, there is the ability to integrate the various imagery and mapping data. DEMThe orthoimagery can be draped over terrain data to create a photo-realistic 3-dimensional model of the landfill site. Contours and other planimetric features can be overlaid on the model, which can be used in GIS visualization software to tour, or ‘fly through,’ the landfill site from the comfort of the office.

Finally there is oblique imagery, which differs from standard aerial imagery in that it provides a 45-degree perspective of the site. Landfill operators find oblique imagery useful for remote viewing of property lines, especially handy for heavily wooded terrain.  This type of imagery also allows a person to see a site from all sides, providing an opportunity for an overall qualitative viewing of a landfill property.

A future possibility is the use of unmanned aerial vehicles (UAVs) outfitted with digital aerial cameras. Sidebar 1-UAV Currently, the FAA prohibits the use of UAVs for commercial use; however, regulations may be modified as UAV technology evolves. Small and lightweight, UAVs could be operated remotely by a person on the ground; ideal for a landfill property, which are typically a few hundred acres in size.

Oct 10

Tracking Impact of Emerald Ash Borer from Aerial Imagery

TP_leaf-on_IR2

Ayres Associates is providing specialized infrared aerial imagery and LiDAR tools for urban tree canopy analysis in the Chicago area.

Municipalities are taking extraordinary measures to deal with the impacts of the Emerald Ash Borer on urban forests. Aerial imagery may provide a useful tool for detecting dead and dying trees and for tracking the decline in the tree canopy.

A recent survey of tree species by the Village of Tinley Park has revealed that most of its 11,000 ash trees within public property had been infested by the invasive beetle.  The results are devastating – much of the urban forest canopy was already dying when the Village made the difficult decision to remove nearly 10,000 susceptible trees within those public areas.  Here’s a link to an article on the Village’s website which details their efforts to remove and replace ash trees within public areas:  www.tinleypark.org/index.aspx?nid=648

TP_leaf-on_IR3 (2)Although Tinley Park and other communities are taking an aggressive approach to combat this beetle, their efforts are focused on the public spaces.  However, many susceptible or dead ash trees remain on private lands where they are no less a problem. These dead and dying trees still have significant impacts on municipalities and pose potential safety hazards for homeowners.  A contraction of urban forest may impact stormwater runoff- causing TP_leaf-on_RGB2localized flooding and erosion. Loss of tree canopy may also lead to reduction in air quality and higher cooling costs in the summer.  Dead and stressed trees can also pose threats when they lose large limbs or topple.

To help communities prepare for these impacts, Ayres Associates has been working to develop methodologies for mapping urban forests.  With our efforts in the Chicago area, we are building workflows to accomplish 3 primary goals using geospatial tools that includes aerial imagery and high density Lidar:

  1. FitchburgChange of Tree Canopy Extent.  Automated extraction of canopy extent is performed from leaf-on aerial imagery collected in 2012 and 2014.  Lidar is also used to attribute canopy height and volume.

  2. Identifying Ash Trees.  “Just-in-time” aerial imagery is collected when ash trees exhibit unique signatures in Infrared imagery. Ground DPtruth information is utilized to train our software to detect trees with similar imagery attributes.  Knowing where ash trees exist in the public space allows us to detect them in private lands and areas of dense, continuous-canopy forests.

  3. Identify Dead/Dying Trees.  High resolution imagery supports the detection of dead and dying trees.  NDVI images also provide an index of vigor/health for individual trees.

There may be no stopping the Emerald Ash Borer, but communities and NDVIhomeowners can be prepared to deal with the impacts of this beetle. Aerial imagery and Lidar can be a useful tool for detecting issues and for managing a healthy urban tree canopy.

 

 

 

 

 

 

Sep 14

Surveying Steamboat Lake – Above and Below the Water Line

steamboat2Merging Bathymetric Survey and Aerial Lidar

IMG_20140708_161203_675aIMG_20140708_112732_642a

 

 

 

 

 

 

steamboat6aAyres Associates is supporting the analysis of the Steamboat Lake with integrated bathymetric and aerial Lidar survey.  Working with GeoSurv Inc. of Lafayette, CO, Ayres conducted a survey of the lake bottom and sub bottom – merging the data with topographic mapping collected from an aerial Lidar mission.

 

steamboat5The survey being conducted for Colorado Parks and Wildlife is supporting an effort to measure the current volumetric capacity of the reservoir and evaluation of methods for increasing its capacity.  Whether exploring options such as rising the height of the dam and/or through dredging, engineers first need to view and measure a continuous surface model consisting of the Lake’s bathymetry and surrounding topography.

Lidar was acquired in June of 2014 at approximately 5 points per square meter to support a vertical accuracy which exceeds 18.5cm RMSE (0.61-ft).  Imagery was captured simultaneously with the Lidar and was processed to 6-inch resolution.

IMG_20140721_125742267aFor the bathymetry, a two man crew and 18’ prop v-bottom boat was used to cut bathymetry sections at 400ft spacing on the lake with cross profiles for quality control. This was performed with a survey grade depth sounder and GPS where the depth is greater than 1ft. Shallow wading shots were also collected and tied into the overbank.

IMG_20140721_122032459aFor the Sub Bottom Profile and Deposition Volume, Ayres used a Ross 4910 dual frequency Sub-Bottom Profiler. Ayres then calculated sediment volume after field calibration.

 

Check out the live webcam from Hahn’s Peak at Steamboat Lake State Park:  http://165.127.23.131/view/index.shtml

 

 

Sep 05

Aerial Photography Supports Ayres Survey & Municipal Projects

Ayres’ RCD30 digital camera provides surveyors with the ability to economically and quickly acquire aerial photography to support field operations.

Denmark10

The Land Survey and Green Bay Municipal engineering groups of Ayres Associates are working with the Village of Denmark, WI (10 miles from Green Bay) in an effort to develop an industrial park on the west side of Interstate 43.

The development will require the preparation of a Certified Survey Map (CSM) and plat maps.  Knowing that the site would eventually be planted with corn before field work could be conducted, the surveyors wanted the ability to capture a snapshot of the site before the ground was obscured by crops.

The Solution: Although Google Earth imagery presents a simple and free option, the poor resolution of the Google imagery does not reveal important details on the ground and does not reference any degree of accuracy.  Additionally, it is difficult to determine if Google imagery sufficiently represents current conditions of the site as the dates of its capture are often unknown.  With this in mind, the surveyors turned to the Aerial Mapping group for an alternative solution.

demark2In May 2014 the Ayres RCD30 digital camera was in the midst of several missions to collect aerial photography at National Guard sites throughout the State.  This gave us the ability to efficiently fly over the Denmark site between project areas at very low cost- and before crops would obscure the ground.  The surveyors provided a project area boundary and ground control targets. The flight plan was prepared to support 3″ resolution imagery.  It was also planned to support 1-ft contours if topographic mapping is eventually needed as well.

RCD30

Because of the many RCD30 mission conducted throughout the year, we can provide high quality aerial imagery for small sites… on short-notice and at very low cost. 

 

The high resolution, high accuracy orthophotography for this site was  accomplished with very low labor and equipment costs. This provides the engineers and surveyors with a clear and up-to-date picture of the site for planning purposes and can be used to create large-format exhibits for display.

Below are comparisons of Google Earth imagery vs. the high resolution imagery from the RCD30 (click on images to view enlargements and zoom in to see detail).

Comparison 1:

 Denmark11

Comparison 2:

Denmark12

 

 

Aug 31

3D Urban Modeling in the Chicago Suburbs

Tinley_Park2Advancements in Lidar processing tools and techniques are enabling new 3D modeling possibilities for GIS.

1-3D houseAyres Associates acquired high density Lidar of Tinley Park, Illinois in the spring of 2014.  The primary objective of the project was the development of 1-ft interval contours and a bare earth surface model for stormwater management applications.  However, there is tremendous value in the point cloud beyond the topographic information.  We used this opportunity to test the ability of software to perform semi-automated feature extraction of structures and vegetation.

As an example, 3D buildings can now be generated from Lidar point clouds and imported into the GIS environment. Our Lidar processing software is able to detect and model 3D planes of building roofs and extrude building sides down from the roof edge to the ground. Despite being a fairly automated process, some degree of manual editing and analyzing tolerance levels for the software is still required.  To improve results, we recommend advanced editing of the point cloud and post-editing of polygons within a GIS environment.

Tinley_Park4For a typical project for 1-ft contour generation we recommend the acquisition of Lidar at approximately 4 points per square meter. For the Tinley Park effort, we acquired the Lidar at 20 points per square meter.

We are demonstrating to our municipal clients in the Chicago area that the increased point density can be achieved at relatively little additional cost. This investment can now permit efficient methods for creating 3D GIS data which can be used for planning, zoning, public safety, and many other municipal departments.

The images below depicts 3D buildings imported into Google Earth Pro:

Tinley_Park8 Tinley_Park6

 

 

 

 

 

 

 

Please see our previous article regarding high density Lidar applications for urban forestry:

http://www.ayresgeospatial.com/2014/05/28/tree-canopy-mapping-from-lidar-in-chicago-region/

 

 

 

 

Aug 26

HD Scanning – Another Tool in the Toolbox

7

In addition to providing high accuracy survey, HD Laser Scanning enables workload and staffing flexibility for the Geospatial Division.

6HD ScanningHD Laser Scanners create a highly detailed and precise point cloud.  After collecting and calibrating the data in the field, the work of measuring and extracting the detailed information for CAD drawings occurs back at the office.  This workflow represents a high degree of cooperation between the Survey and Aerial Mapping groups at Ayres Associates: the surveyors perform the scan and calibrate the data to known coordinates while the Lidar technicians in the Aerial Mapping group use specialized software for data extraction.  The shared resources and expertise allows us to quickly respond to our clients’ survey needs even during peak workload.

trueview1Whether preparing a CAD drawing for transportation design or electrical engineering applications, our two groups provide the combined expertise to efficiently survey and map any site.  Together we also possess a wide range of specialized software – each tailored to a specific application.

The graphics to the right depict Lidar point cloud images as represented in Leica’s trueview2TrueView software.  This Internet Explorer-based add-on enables a viewer to easily prepare 3D measurement and output displays for quick reference.

To derive the data for CAD drawing, the Aerial Mapping group utilizes TopoDOT and Cardinal VrOne, both common tool for DOT and transportation design mapping.

The images below show the planimetrics and DTM breaklines extracted from the Lidar point cloud in a Microstation environment. The 3D drawings can then formatted to DOT or other client-specific specifications in Microstation or Civil3D.

10

11

 

12

Please see our previous post from July 15 for additional information related to data extraction from HD Scanning.

 

 

 

 

 

 

Jul 15

Street Level Mapping from Laser Scanner

Kewaunee Leica P-20 (7)

Laser scanners provide a unique perspective for municipal survey and mapping.

A 3D point cloud generated using a Leica P20 Laser Scanner is used by our Lidar specialists to extract digital terrain data and planimetrics- recreating traditional CAD-based mapping compiled from conventional survey and photogrammetry.

For this example, we compiled curb and gutter, utilities, improvements, and other structures along a road corridor and several intersections.  The mapping derived for this municipality in northeaster Wisconsin was compiled to match typical DOT specifications.

Kewaunee Leica P-20 (8)

 

Kewaunee Leica P-20 (5)Laser Scanning can also be used to generate 3D streetscapes and building facades for planning and zoning applications.  Feature extraction of utilities and other municipal assets can be accurately collected for integration into GIS geodatabase.

Kewaunee Leica P-20 (2) Kewaunee Leica P-20 (6)

Jul 02

Aerial Imagery Captures Recent History of Flooding in Greeley, CO

G4Flood events in Colorado in 2013 and 2014 have been recorded using aerial imagery- providing the City of Greeley with a valuable tool for assessing flood extent and for analyzing storm water infrastructure and improvements.

 

G1In September of 2013, Ayres Associates collected aerial imagery of the South Platte River and its tributaries near peak flood stage, including the Cache la Poudre River through Greeley.  The imagery provided an overview of flood extents throughout much of the Front Range and has since been used extensively for the recovery efforts.

In June of 2014, the City of Greeley contacted Ayres Associates with a request to capture another major flood event along the Poudre River.  In this instance, a flight crew was mobilized within 2 hours of notice to proceed and captured the flood extents for a 17 mile segment of the River.

The June 2014 event is considered by engineers as somewhere between a 10 to 50 year flood event. This was relatively minor in comparison to the historic September 2013 floods as a whole but this June 2014 flow in the Cache la Poudre River through the city was actually slightly larger and more damaging than in the September floods.  The flow event was more damaging for a couple of big reasons: first, the June event had a longer duration and therefore filled more of the overbank storage and, in turn, caused 
more flooding. Secondly, it is believed that some of the overbank infrastructure had been weakened and/or saturated by the previous 2013 event.

A previous aerial photography mission from fall 2012 represents normal conditions along the Poudre.  Analyzing the imagery from all 3 missions provides stormwater managers and engineers with valuable tools for addressing improvements and focusing on recovery.

G2

Read more about the 2013 aerial imagery project here:

http://www.ayresgeospatial.com/2014/05/01/ayres-associates-featured-in-leica-article-on-colorado-floods/

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  

Older posts «

» Newer posts