FAQ

1. How did WROC start?

In 2005 three Regional Planning Commissions (RPCs) coordinated the single largest mapping initiative in Wisconsin history. This project included 35 counties and 100 additional partners to acquire aerial imagery and planimetric mapping. In 2008 seven RPCs decided to work together to coordinate an even larger organized mapping initiative for 2010. This project has been named the Wisconsin Regional Orthophotography Consortium or WROC.  In 2010 WROC became the first state-wide single year leaf-off dataset in Wisconsin history.  WROC acquired over 56,000 sq miles of imagery.

2. How does an organization benefit from being a member of WROC?

The WROC program brings a number of benefits to its members, including:

  • Cost savings
  • Specifications and standards support
  • Data sharing between members
  • Procurement support

3. How does an organization become a member of WROC?

A member is defined as an organization that is completing a local project through WROC. There are two stages of membership. The first stage is when a county or local unit of government signs a letter of intent (LOI). The LOI states that a member intends to do a project if funding becomes available. The second stage of membership is reached when they become a full member by signing a contract with the Ayres Associates/Aero-Metric team to complete a project.

4. How does an organization become a partner in WROC?

A partner is defined as an organization that is providing a cost share to WROC members to facilitate the completion of their projects, resulting in access to higher resolution datasets over larger geographic regions at a greatly reduced cost to the partner.  Partner cost shares will be determined on a case-by-case basis, depending on such factors as the total area, resolution, and degree of customization of the dataset. Cost shares are dependent on the specific technical requirements of each dataset. Cost shares for all partners will be identical for identical datasets.  Member approval is required before any partnership arrangements are finalized.  Contact a WROC representative to learn more about becoming a partner in WROC.

5. As more partners join WROC, how do all partners benefit?

WROC is currently structured so that participating county and local governments fund 100% of the upfront cost of their projects. All partner funding, minus the cost of customization and delivery of the partner dataset, is distributed to WROC members.  As more partners join, overall project costs decrease for WROC members, thereby creating more and more incentive for members (i.e., county and local governments) to participate. Greater member participation in the program benefits members by attracting more partnership opportunities; for all partners, greater participation ultimately means increased availability of larger regions of data at greatly reduced costs.

6. When do partners have to pay their contribution?

Partners must pay their contribution within 30 days after delivery and acceptance of the partner dataset.

7. What time of day are images acquired?
A: All imagery is acquired when the sun angle is at 30 degrees or greater to minimize the obscuring of ground features that lie within the shadows of vertical features. The actual time of day where the sun is at 30 degrees or higher in the sky varies depending on region and calendar date.

8. What are the approximate flying heights for the various ortho scales and resolutions?

3” resolution/1”=50’ scale: 2,500 feet above mean terrain (AMT)
6” resolution/1”=100’ scale: 5,000 feet above mean terrain (AMT)
12” resolution/1”=200’ scale: 10,000 feet above mean terrain (AMT)
18” resolution/1”=400’ scale: 14,400 feet above mean terrain (AMT)

9. What are the approximate file sizes for the various ortho scales and resolutions?

True Color/3” resolution//1”=50’ scale/PLSS Quarter Section: 325 (megabyte) MB
True Color/6” resolution/1”=100’ scale/ PLSS Section: 350 MB
True Color/12” resolution/1”=200’ scale/4 PLSS Sections: 425 MB
True Color/18” resolution/1”=400’ scale/9 PLSS Sections: 450 MB

10. Do you provide FGDC metadata?

Yes, all orthoimagery and other map products will be delivered with associated FGDC compliant metadata.

11. What is the deadline for joining WROC?

WROC is planning for Spring 2020 aerial acquisition missions.  Members are encouraged to have their projects under contract by January 2020.  There is no deadline for a partner to join WROC. Partners are encouraged to step forward before the projects start to provide the funding assistance necessary to make more projects happen.

12. Can you designate certain areas within the county for 3″, 6″, 12″?

Yes. Many consortium participants in the past have designated areas of higher resolution imagery, generally in more urbanized areas, and then collected slightly lower resolution imagery for the remainder of the project area. Typically that results in two different resolutions for the same area, because it is much more cost effective to fly over the inset area during the lower resolution flight than to avoid it by turning the aircraft more often. Based on already received feedback, we anticipate many participants will have higher resolution imagery for municipal areas, stitched into a lower resolution countywide data set. These are perfect projects for WROC since we will already have sensors in the area for municipal clients to take advantage of while county clients benefit from data sharing of the high resolution urban orthos.

13. How does this imagery differ from the imagery on Google?

There are a number of differences between the imagery provided through WROC and Google imagery. The three key differences are leaf off imagery, sun angle during collection, and accuracy.  Imagery through WROC is guaranteed to be collected during leaf off conditions unless otherwise specified by the participant. In some cases Google imagery may be captured during leaf off conditions but it is not guaranteed. Secondly, there are sun angle restrictions in place during collection of all WROC imagery to decrease the amount of features obscured by shadows from vertical features. A majority of the shadows that exist in Google imagery would be deemed unacceptable by most previous WROC participants. The third key difference is accuracy. The WROC imagery is provided at a stated accuracy, and is –geo-referenced to meet that stated accuracy. If there are ever any issues with the accuracy of WROC orthoimagery within your area, the WROC team will check the ground control and ortho processing in order to make the necessary adjustments.

14. Will the deliverables be in County Coordinates or something else?

Base deliverables for all WROC county projects will be in county coordinates. However, we can reformat and deliver the entire dataset into other coordinate systems, such as geographic coordinates for E911 purposes. The additional formatting will be done at a nominal fee, which many times can be covered by a partner who is requesting the alternate coordinate system.

15. Can out of state areas bordering Wisconsin participate in WROC as well?

Yes. In the past there have been a number of counties bordering Wisconsin that have participated in WROC. Extending coverage is not only beneficial for the out-of-state community, but also for the adjacent Wisconsin communities. If you are border county or municipality and would like to reach out to an adjacent neighboring community under WROC, please contact a WROC representative who will be willing to assist in that process.

16. What, if any, ground control data would be requested of participants?

Ground control data for imagery projects within the state have become less and less of a requirement because of the implementation of Wisconsin Continuously Operating Reference Stations (WISCORS) and the advancement of airborne global navigation satellite systems and inertial measurement technology that is aboard all aircraft used for WROC. Any additional ground control required for your project will be included within the costs outlined in the pricing table. [We do, however, encourage all participants to panel your own independent check points for validation of the positional accuracy of the delivered orthoimagery.