Simple, Inexpensive Aerial Photography Mapping with Balloons or Kites

Engineers Without Borders West Coast Regional Workshop 2010Patrick Coyle, EWB-SFP; Grassroots Mapping, Belize Open Source -

Sustainable DevelopmentOctober 30, 2010

Agenda• Why bother? Aerial photomaps

can be very useful• Community, Site & Project

Planning; Agricultural/ Ecological planning, evaluation

• How? In summary, what’s needed?

• Equipment, Software, Supplies, Materials

• Step-by-step guide• Examples from community of

users• Demonstration – let’s fly!• Stop by after – see results, Q&A

• Jeff Warren, Grassroots Mapping, produced community maps in Lima Peru with children and adults

Step-by-step guide

For example, here is Coyle’s preliminary set of requirements:• Take detailed aerial photos of the Belize Open Source Sustainable Development

40-acre property with enough detail that individual trees are clear• Cover the site with overlapping images and use software to stitch them together

into a single photomap and georegister it to Google Earth imagery of the property

• Tag the individual photos with GPS data to georeference them for viewing on Google Maps, Google Earth, or others

• Develop methods to use the photomaps for work planning, tracking progress and communicating results to encourage participation in the initiative. Document the approach and techniques

• Apply the method to other community mapping initiatives and make it available for other users like EWB and schools and communities in Belize

• Decide what you want to do, produce and deliver; thinking this through will help to define the requirements

What’s needed?• Digital camera with ability to take photos automatically (at say 10-

second intervals)• GPS unit with tracking and logging capability (optional, where needed)• A package to house the camera and GPS unit• Balloon or kite with enough lift capability to carry the camera, GPS unit,

housing and sufficient tether line to reach height of interest for the photographs

• A safe area to test the system and process and a safe approach to use the process in the field

• Capability to process the data and present the results• An approach to discuss and use the results

A complete grassroots mapping kit

Illustrated Guide (By Jeffrey Warren)

Illustrated Guide (cont.)

Illustrated Guide (cont.)

Illustrated Guide (cont.)

Illustrated Guide (cont.)

Illustrated Guide (cont.)

“Neogeographic” approach to inexpensive oil spill mapping

• In late April 2010, the Deepwater Horizon oil rig exploded and sank in the Gulf of Mexico, initiating what may be one of the worst environmental disasters in U.S. history

• As the spill grew in size, Jeffrey Warren and Stewart Long collaborated with the Louisiana Bucket Brigade, a New Orleans-based environmental non-profit group, and began a volunteer-led aerial mapping project to document the spill’s effects

• The maps use orthorectified photographs of key affected sites processed into GeoTIFFs and tiled map services (TMS) - the public domain photographs, taken from balloons or kites, are among the highest resolution imagery available of the spill

Oil Spill Mapping Kits• The mapping kits themselves,

assembled for less than $300 each, consisted of:

• an 8-foot weather balloon• a tank of helium• 2000 feet of string• an inexpensive, consumer

grade digital camera• half of a soda bottle• a large kite• GPS logger (optional)

Oil spill mapping approach• Participants visit an

affected area, fill a balloon or prepare a kite depending on wind conditions, and send the camera in its homemade protective enclosure up to 2000 feet in the air

• By walking along the beach or moving in a boat, several kilometers of coastline may be imaged in just a few hours

• Some maps, at ~ 2-3 cm nominal resolution, can count birds, plants and other features, even identify bird species

Oil spill mapping trips and data• Between May 7 and July

22, dozens of participants made 36 trips to gather mapping data, averaging almost one trip every other day

• Only one trip failed to return with imagery, 56% of the trips returned with "excellent" or "usable" data, and over 11,000 images were taken, with plans and funding in place to continue mapping through January 2011

• This is a case where the low-cost mapping techniques were applied to a real-world problem of immediate importance

Orthorectification (stitching) techniques• Two different manual processing methods have accounted for

the bulk of the mapping for Grassroots Mapping grassrootsmapping.org to date:

• Gonzo Earth Image Processing is a workflow of different commercial off-the-shelf (COTS) and open-source GIS and digital image software packages, which has been used to generate dozens of maps from balloons, kites, remote controlled and manned aircraft

• The Cartagen Knitter software consists of a free web-based interface for users to upload and rectify images from a web browser

• Both export finished maps in standard formats including GeoTIFF and TMS, to be viewed in common GIS tools and integration into existing workflows

A Grassroots Mapping collaboration in Georgia

• In the country of Georgia, Grassroots Mapping techniques were used alongside more traditional GPS-based approaches by the OpenMapsCaucasus.org effort to produce a public domain map of the entire country

• A map of Mestia, in the Svaneti region of Georgia. The map spans 5.5 kilometers and was captured in just 3 days of balloon and kite mapping with local OpenMapsCaucasus staff and participating students

• Flight paths of several balloon mapping flights in Mestia, Georgia, during a 3-day project to map the entire city

• The pictured flights reached 1.4 kilometers above ground level

Grassroots Mapping Belize

• Grassroots Mapping Belize - Pat Coyle of Belize Open Source Sustainable Development is looking to apply these techniques to detailed mapping of a 40-acre property in northwest Belize and for other community mapping initiatives

• To date, I have commissioned the mapping kit and processed test images in Livermore, CA

Site: Belize Open Source Sustainable Development

• This 40-acre rural property is located in northwestern Belize near the Mexican and Guatemala borders about 16 miles from Orange Walk Town, between the villages of August Pine Ridge and San Felipe and 3.5 miles to Rio Hondo Belize/Mexico border

belizeopensource.org

• Google Maps shows it, but two more clicks in and you run out of pixels

• Balloon test flight in the front yard with neighbors

Stitched test photos

Get Involved• grassrootsmapping.org• Wiki: techniques and

tools, case studies• Participate: join the

Mailing List!• Start a grassroots

mapping project today!

• Apply techniques to your project

Grass Roots Mapping Supporters and Collaborators

You

The Design Ecology group at the MIT Media Lab

Let’s fly; stop back later: for results, Q&A