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OpenAerialMap – Think Open Street Map for imagery..

Open Aerial Map

As happens in this world of constant communications, I heard of the new OpenAerialMap site via an IM chat with Jeff Johnson of PictEarth on Sunday lunchtime !

The idea behind OAM is for it to become an online repository for community generated aerial photography, sourced from Kites, Low cost UAV’s , etc. I’m sure many still see the creation of Open Source imagery captured by amateurs as a Joke, but then people were not serious about OSM !

It’s true that OAM cannot really replace the global systematic cover offered by satellite imagery or the professional aerial photography producers, but for applications where discrete imagery is required of a particular location at high resolution, or to cover a specific event or activity (high temporal resolution) there is a niche which can be filled by this imagery, and the services like OAM which distribute it.

As with OSM, OAM can work because the tools to both capture and distribute this type of Geodata have become democratised to the extent where it is possible for the amateur to respond to events faster than the professional,and to make that data available without the restrictions of conventional licensing. Although the distribution of large amounts of imagery represents all sorts of new challenges in developing a robust operational system.

As with traditional mapping, we are not looking at a replacement to the traditional top-down centralist approach to the creation of Geodata, however there is now at least an alternative, that may become more significant over time.

I wonder if there are plans to use include Geobase SPOT data set of Canada ?

Written and submitted from home, using my home 802.11 network.

7 replies on “OpenAerialMap – Think Open Street Map for imagery..”

“IâÂ?Â?m sure many still see the creation of Open Source imagery captured by amateurs as a Joke, but then people were not serious about OSM !”

There’s an extremely big difference between creating roadlines using a GPS to generate aerial imagery coverages. First of all, you will need a terrain model to orthorectify the imagery and either exact position and orientation of the camera and/or 4-6 Ground Control Points in each image. How will you get this? Granted there are free terrain models, but they are only usuable for low-resolution imagery made from high-altitude imagery (which OAM is not). And I don’t think they realize the amount of post-processing, camera calibration, color adjustments, etc that it would require when using thousands of different amateur cameras and imagery taken under thousands of different conditions and at different times of the year.

Pete

You right. For part of quests (distortion, perspective correction) we have himself realtime software.
For DEM correction, color adjustments, mosaics we simple make interface to popular applications. In next wanted see processing near to realtime. OAM is process and we can return to database of primary data in next for enchanced adjustments (if this need). List of OAM applications while opened. We want see new OAM applications, components, ideas, concepts.

Thanks you.

Pete: ‘First of all, you will need a terrain model to orthorectify the imagery and either exact position and orientation of the camera and/or 4-6 Ground Control Points in each image. How will you get this? ‘

One way would be to use the GPS database held by OSM. This probably wouldn’t adequately adjust for relief though – for this you need a DEM. But if you are a commercial company who need orthorectified imagery, you either need to pay someone for it or get hold of imagery and a DEM. So why not skip the imager, grab freely available imagery from OAM, use your own DEM to orthorectify it and dramatically cut your costs.

Building ortho photos is really hard, you need much better cameras than those used so far, and detailed DEM’s so I don’t think we will be seeing many community generated orthoimagery data-sets in the near future.

On the other hand for the vast majority of applications on the web, geo-matched imagery, i.e. corrected just to match the underlining base map data is good enough.

Pete is right here to think it is a joke to think that there will ever be a large dataset of community generated ORTHO-imagery. Ortho imagery requires quality elevation models and a rigorous sensor model. But OAM is about much more that community generated imagery. It is also about having a dataset that has very little if any restrictions on its use, which is built from freely available government sources (much in the same way that OSM uses TIGER data here in the US). For instance, the OAM project is looking into bringing the NAIP (http://165.221.201.14/NAIP.html) dataset online as well as the Canadian geobase mentioned. In the US where each government agency acquires data and then choses to publish it in various and sundry ways (many times with proprietary commercial software), it will be a relief for those of us that want to use this data to be able to grab it from a single coherent source.

As for the idea that Amateurs cannot produce quality rectfied (again NOT orthorectified) imagery. I encourage anyone to look around in the OAM datasets. In particular sets like this one … http://openaerialmap.org/map/?lat=32.90079&lon=-117.24309&zoom=17&layers=BF … on the left is imagery shot with a normal (non SLR) digital camera) and on the right is proper Orthophotography. What is necessary for amateurs to be able to rectify their imagery is a proper high resolution base image dataset. Fortunately for us in the US, we have one which is freely available. For many other parts of the world, it is quite easy to use Google Earth or Virtual Earth to derive Ground Control Points … and FYI Pete, 4-6 is not nearly enough, for this kind of photography, 15-20 is more in the ballpark.

“I wonder if there are plans to use include Geobase SPOT data set of Canada ?”

http://wiki.openstreetmap.org/wiki/GeoBase_Import
Now that the OpenStreetMap foundation has decided that the GeoBase license is of acceptable use for the OpenStreetMap project, this opens the door that the Satellite images are also available. I haven’t checked to see about adding these images to OpenAerialMap, but I will add it to the list of possibilities. The other is to have it as a WMS layer like yahoo imagery is on.

Sam

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