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I'm looking for service that provides me a change detection service based on a database of remotely sensed data. Has anybody happen to know such a service? The service I am looking for is a geoportal that alarms the user of a specific change (like oil spill or major coastal change or even fire in forest) in a specific area or globally. It can be either freely available service or on-demand service.

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Change detection is a vague term. Please explain your question. I dont think you will have any out of the box solution. –  Naresh Jun 26 '13 at 14:26
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Agreed - this question requires a lot more detail. –  Nick Ochoski Jun 28 '13 at 18:38
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like what? It is clear what I want. I even suggested some examples –  f.ashouri Jun 28 '13 at 18:40
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The problem may be that how "change detection" is carried out depends on many things: what is being detected, with what kinds of sensors, over what periods of time, with how many different samples, at what resolution and extent, and for what purpose. If you were to narrow your question to a specific application, such as sighting fires (which is different from identifying changes in coastlines on almost all the characteristics I named), you might have a chance of getting a positive answer. –  whuber Jun 28 '13 at 19:03
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Dear @whuber, if you find good example of for even one of applications I named or you named, it is OK for me. Thanks a lot –  f.ashouri Jun 28 '13 at 19:07

4 Answers 4

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One of the most powerful near-real time change detection tools I've encountered is EOSDIS Worldview.

This new tool from NASA's EOSDIS allows users to interactively browse satellite imagery in near real-time, generally within 3 hours of observation. Use the tools described below to change the imagery on the map and compare it to past observations.

There are many interest areas including the following:

enter image description here

For example, the following is a screenshot of remotely sensed fire detections.

enter image description here

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Well, I think you need two different things, first of all you need a source of information, such source have to come in the GeoRSS standard or in the GeoJSON standard (I prefer the latter), here is an example:

USGS Real-time, worldwide earthquake list for the past 7 day [GeoRSS]

USGS Real-time, worldwide earthquake list for the past 7 day [GeoJSON]

Once you have the source, you need a GeoRSS/GeoJSON aggregator, use these terms in your search to find more examples,

here is the one that uses GeoRSS , I believe that the enterprise version allows you to send you alerts just like you want to:

GeoCommons

But wait this is no 2008, the good thing about geojson is its ease of use, so here is an example from mapbox of how to integrate a geojson feed into their maps, where you could make almost anything with it (of course needs some coding):

MapBox : Loading GeoJSON into Markers

MapBox also offers a GUI version of all their tools, I would check into that too.

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I don't think you're going to find what you're looking for, and even if you did I would advise against using it. Web services are well suited to generic, simple, and repeatable operations where generating output requires nothing more than using set business logic to process input.

As others have mentioned in comments above, change detection is a very vague term and how that detection is performed will vary based on its application. Even when performing change detection on a small and well-known patch of woodland the methodology would vary depending on if you were looking for deforestation or the spread of disease.

To have any kind of meaning change detection requires human input. You could send two images of the same area taken one hour apart into a change detection web service and be told that a huge change had taken place. Once you looked at the images you might see that the second image had more or less cloud cover than the first. Without interpretation the alarm 'something has changed' is meaningless.

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Google

Google Earth Engine stores numerous time stamped public domain datasets including:

  • Daily MODIS outputs (very low resolution) such as surface reflectance and NVDI.
  • Periodic Landsat composites, now including Landsat 8.

Although you may not be able to access analysis outputs it is effective at visualising change at small scale. This page shows landsat change from 1984 to 2012.

Astrium (commercial)

Change detection based on Synthetic Aperture Radar Satellites:

  • Millimetre range Surface movement detection.
  • General change detection mapping of major events and site monitoring.

I have never used the direct access (pdf) service so don't know how it is accessed.

ESRI

The ESRI ChangeMatters site shows differences in Landsat data over a range of years. It includes common visualisations such as NVDI change.

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