HomeMy WebLinkAboutItem 8.2 RegionalAerialPhoto
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CITY OF DUBLIN
AGENDA STATEMENT
CITY COUNCIL MEETING DATE: March 13, 1995
SUBJECT: Authorization To Participate In Regional Aerial Photography Project
't9 (Prepared by: Bo Barker, Management Assistant)
EXHIBITS ATTACHED: /Description of Work Tasks To Be Included In The Project
RECOMMENDATION:. ./1.
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Conceptually approve the City's participation in the regional aerial
photography project.
Direct Staff to finalize an agreement with other jurisdictions for approval
at a City Council meeting in the future.
FINANCIAL STATEMENT: The total cost of the project is estimated to be $41,031, assuming that all
agencies identified with interests similar to Dublin participate. A budget
adjustment for $6,613 is necessary for Fiscal Year 1994-95 to fund initial
phases of the project. The remainder of the project $34,400 will need to be
budgeted in Fiscal Year 1995-96.
DESCRIPTION:
THE PROJECT AND PARTICIPANTS
The City of San Ramon acted as the lead agency for coordinating a regional photography project. The
approach was structured in a manner which attempted to provide a cost sharing arrangement for all
participants. The City of San Ramon has extended an opportunity for the City of Dublin to participate in
the project, which will potentially provide information at a lower cost than the City would incur if the
information were gathered solely for one agency.
AN OVERVIEW OF AERIAL PHOTOGRAPHY
The ultimate goal of this project is to utilize computers to distribute and update aerial photographs to
city departments and the public. This is done by taking aerial photos of the different segments of the
City and converting that information into an electronic, or digital format that can be read by ~ computer.
This means, for example, if the police or fire department received a call regarding an incident, they
could receive visual information about an incident scene before they actually arrive at the location.
Using electronic or digital photos with the computer is possible through the use of software applications
known as Geographic Information Systems (GIS). Using GIS, the City can also link the digital aerial
photos with other database information. For example, the Economic Development Manager could
quickly respond to a prospective business by faxing not only a picture of the site but also information
such as square footage, lot size, zoning, and the current owner. Aerial photography is valuable as a
customer service tool. The table below describes various ways City departments can use digital aerial
photography in the day to day operations,
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the city. Photos of available lots and other ffiU~~!~::;;;mmljt::
dat~base information, such as size, current f~~~r1~II[i.1i
zOning, etc. could qUickly be faxed or sent tlW/WEbntf
to prospective customers. ~lf!i;;::;;!I.::::::~.
2, Enhance business Development Analysis H'M]~nmC:
(total buildings and square footage) :~\!t~I~;J.lit:::
3. ;~;:~~~~:.esenlation lools for business _: 1
Police Deoartment
Provide visual representation of any
location in the City thereby improving
operational planning.
Improve the ability of the Police Services to
respond to incidents in the City.
Pre-incident response planning.
Provide visual tools to respond to customer
in uiries.
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COPIES TO:
CITY CLERK
FILE~
ITEM NO.S. 2
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Public Works
Improve the ability for traffic signal and
street sign inventory and planning.
Establish a system that would allow the
department to measure distances for street
improvements and pavement management
systems.
Assist with intersection planning.
Enhance capital project design and
planning
Improve service to public for any inquiries
about no parking zones, loading zones,
etc.
Improve stripping and marking planning.
Improve ability to accurately present City
Council with representations of site
conditions. This would include driveway
access and other encroachment issues.
As indicated above, there are many uses for electronic aerial photos. The common theme above is
quicker and improved customer service in all areas, but primarily related to economic and community
development.
PROJECT TIMING
City of Dublin Staff have participated in various discussions and presentations coordinated by the City
of San Ramon. However, the time frame for implementing the project is being driven by other agencies
which have a current need for digital information to incorporate into their data processing information
systems. The City of San Ramon has indicated that if entities desire to participate after this initial
offering, there would be additional charges including a pro~rata share of the City of San Ramon Staff
time to coordinate the project.
The City of San Ramon initiated a consultant selection process beginning in August, 1994 when they
distributed 70 Requests for Qualifications to consultants/vendors for the Aerial Photography Project.
Twenty (20) firms responded to the RFQ and six (6) were invited to respond to the formal Request for
Proposals. Following a review of the responses and interviews, the firm of Hammon, Jensen, Wallen
and Associates was selected.
Keeping in mind the number of agencies interested in this program, the City of San Ramon pursued
multi-agency agreements with a number of organizations. These include, the City of Dublin, Alameda
and Contra Costa Counties, Dublin San Ramon Services District, East Bay Municipal Utility District,
East Bay Regional Park District, San Ramon Valley Fire Protection District, and Viacom Cable. Each
agency established their particular zones of interest. Although the Dougherty Regional Fire Authority
(DRFA) would benefit from this information, it is not listed as a separate participant because DRFA is
funded jointly through the Cities of Dublin and San Ramon. The Dougherty Regional Fire Authority
would receive all applicable products through the participation by its member agencies.
COSTS
The total cost of this project for the City of Dublin is estimated to be $41,013. This funds a full set of
printed aerial photos in addition to the electronic conversion of the photos. Without the multi-
jurisdictional cooperation, it is estimated that the same project would cost approximately $97,080. The
cost to do it alone does not include the staff resources that would be necessary to prepare an RFP and
selection of a vendor. By comparison the City's current set of base maps and aerial photographs were
produced at a cost of $94,427 between 1983 and 1986. These maps did not include conversion into a
digital format.
The cost per each sub-category is listed in the table below. These terms tend to be more technical. A
more, non-technical, description is provided in Exhibit 1.
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Task
Ground Control
Aerial Photography
Aerotriangulation
Road Features ~ No Center Line
Road Center Line
Other Planimetry
DTM
Digital Orthophotos
Parcel Rectification
Contours
Plots of Orthos
Plots of Parcels
Total Each Zone
Total
$3,303
1,206
2,104
4,639
3,098
1,397
6,512
5,678
666
3,730
3,720
4,960
$41,013
* These estimates reflect participation by Viacom Cable, the Dublin San Ramon Services District and
Alameda County. These are agencies interested in the same products as the City.
The entire project is estimated to be completed 14 months from the start date. By approving the
project, the City would need to fund $6,613 in Fiscal Year 1994-95 which would cover the costs of the
aerial photography, aerotriangulation and Ground Controls. The remaining $34,400 would need to be
funded in Fiscal Year 1995-96.
RELATIONSHIP OF PROJECT TO CITY OF DUBLIN INFORMATION SYSTEM MASTER PLAN
In October, 1994 the City Council adopted the Information Systems Master Plan. This plan included a
number of enhancements to the information systems of the City, including a new local area network
and the addition of software programs. The Master Plan provided for the phased implementation of
new applications as part of the five year Capital Improvement Program (CIP).
Included in the update of the CIP document, Staff will be evaluating the ability to meet the current
schedule given available staffing and the number of high priority objectives. This schedule may be
extended in the 1995-96 update to the five year CIP.
When the Master Plan was developed, aerial photography was not included as part of the project for
the following reasons: 1) The only cost estimates available were over $100,000; 2) Benefits relative to
those costs would not make the project worth while. It should be noted that although it was not
included as part of the Data Processing Program there may still remain a need to update the existing
City Aerial Photos.
The work completed by the City of San Ramon provides the City of Dublin with an opportunity to
participate in a regional aerial photography project that could provide electronic map information at
costs much lower than earlier estimates. The proposed project would provide the City with the
following major categories of information.
1. A current set of aerial photographs containing greater detail than the photos
completed in 1983.
2. Information in a digital format which could be used in the future once a Geographic
Information System Software Application is implemented.
The data collected by this project is only one element of data which could be applied to a Geographic
Information System (GIS). The Master Plan assumed that permit tracking and other parcel related data
would be implemented prior to the implementation of GIS software. The GIS implementation is
scheduled for Fiscal Year 96-97. The ability to manipulate aerial photography on the computer is done
through GIS applications. Thus, the GIS program must be purchased prior to implementing full use of
the electronic maps.
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Conclusion: Due to the opportunity to share costs and receive a extremely useful tool, Staff
recommends the City Council approve, in concept, participation in this regional endeavor. It is also
recommended the City Council direct Staff to proceed with negotiations in order to finalize the
agreement for services.
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Description of Work Task Included
In the Multi-Agency Aerial Photography Project
Ground Control
This element establishes a coordinate system for the aerial photography. Using a well defined
coordinate system is important because it establishes a mechanism for combining two parts of a
map stored on a computer to actual points that have been surveyed. This project will utilize a
coordinate system which is considered a standard by many agencies undertaking mapping
projects. Ground controls provide a mechanism for measuring features within the City with an
accuracy within 2' -5'. A Ground control based system will also allow the City to tie into other
maps that are on the same coordinate system. This type of coordination will be beneficial to
those agencies which serve more than one jurisdiction (Le. DRFA and DSRSD). Also, it will
increase the likelihood that maps generated in the future by other entities will overlay information
collected by the City.
Aerial Photography
This is the act of actually taking a picture of the City from an airplane. The primary cost factor for
this procedure is the altitude at which the photo is taken. It is proposed that the built-out section
of the City be taken at a scale of 1"=100' and other areas be taken at 1"=200'. This will be an
improvement over the City's current photos which are at a scale of 1 "=200'
Aerotrlangulation (A T)
This is a method that the consultant uses to tie multiple photographs together, in conjunction with
the established ground controls. AT allows two pictures to be placed side by side and be
coordinated as if they were taken as one picture. This process involves making digital
adjustments to compensate for the distortion which occurs on the perimeter of an aerial
photograph.
Road Features - No Center Line
This task involves the digital tracing of the following images:
Edge of Pavement
Curbs
Sidewalks
Pavement Striping
Medians
Median Curbs
Alleys
Unpaved Roads
Iron Horse Trail
Interstate 680
Bridges and Overpasses
This information can then be printed as a separate layer. When combined with"Geographic
Information System software, the information can be used to estimated roadway widths and other
improvements. This can be helpful in preparing plans and specifications for annual maintenance
projects such as slurry seal and street overly projects.
Road Center Line
This task adds Road Center lines in the same manner discussed above. All roads, even if they
have a median will include a digitized center line. Road Center Lines assist with measurements
Exhibit 1
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and distances for such activities as pavement management systems. Road Center lines are used
with GIS software to attach information regarding the roads.
Other Planimetry
Planimetry is the process which takes place when the consulting firm adds lines which trace
features. This is similar to the tracing of the roadway features such as edge of pavement, curbs,
sidewalks, etc. The features proposed to be added include publiC facilities such as building roof
lines, Major Parks and Recreation Equipment, Parking lots, internal circulation features and any
City trails.
Digital Terrain Model (DTM)
The Digital Terrain Model is used to collect contours on the digital photos. DTM is computer
terminology for software that provides the ability to generate elevations at selected points on the
photo. The information can be used for slope analysis, view shed analysis, or flood planning.
The DTM also contains 3D streams and creeks.
Contours
Using the DTM, information in the computer will generate the expected contour lines between
plotted points. Contours are used by Engineers for drainage studies and slope evaluations. The
Fire Department uses this information for hazardous spill response and planning.
Digital Orthophotos
This refers to the actual images or photographs. The photo is scanned and placed in an
electronic or digital format that the computer can read. These photos consist gray scale images.
Once the Geographic Information System software is available, the electronic photos can be
printed for use at the Community Development counter or used over the local area network.
Parcel Rectification
This a process by which the contractor takes a digital base map and adjusts the vectors (lines) on
the base map to match the digital photos. This process is necessary because the base. maps are
not based on a true coordinate system. The end result of this process is that the City's base map
would be based on the standardized coordinate system and the parcels of that base map will line
up with the electronic photos.
Plots olOrthos
Plotting means printing. This portion of the project consists of providing the City with a full set of
printed orthophotos. There would be a total of 62 sheets (0 size - 22" x 34") covering the entire
City. A total of 45 sheets constitute the existing City limits west of Dougherty Road and a total of
17 sheets make up the two zones consisting of everything east of Dougherty Road.
Plots 01 Parcels
As stated above, using a base map provided by the City all parcels with be rectified (aligned) with
the orthophotos. Plots of Parcels means that the City may purChase printed copies of parcels
that will be printed with the orthophote.