Geoinformatic | Abdulhakim Abdi

Russian Satellite Takes Definitive Photograph of Earth at 121 Megapixels

admin — Mon, 14 May 2012 14:58:50 +0000

A new Russian weather satellite takes half-hourly snapshots of planet Earth in unprecedented detail – with a 121-megapixel camera

Beautiful detailed images of our planet are being shot by a new Russian weather satellite, named Electro-L. Every 30 minutes, the geostationary satellite takes a photograph from a distance of 22,000 miles above the equator – at unprecedented detail.

Each image has an ultra-high resolution of 121 million pixels and show the rich deep blues of the oceans contrasting with white fluffy clouds and sharp outlines of land.

Hitherto similarly detailed images were taken by NASA and other agencies by stitching multiple snapshots together – but Electro-L’s pictures are taken in a single shot and then transmitted at high speed to ground stations on Earth.

Electro-L’s images are a combination of visible and near-infrared wavelengths, resulting in vegetation appearing as red rather then the expected green colour.

The Electro-L satellite is the first major spacecraft to be developed in post-Soviet Russia. It provides local and global weather forecasting and analysis of ocean conditions, as well as “space weather” monitoring — measurements of solar radiation and how it interacts with Earth’s magnetic field. Its initial lifespan is projected to be ten years.

The full resolution image can be viewed at GigaPan and read more on Gizmodo.

Image credit: NTsOMZ. Image processing: James Drake.

Support from the NSF & AAG to attend the 32nd International Geographical Congress in Cologne, Germany

admin — Sun, 22 Apr 2012 01:33:24 +0000

Thanks to a junior scholar grant from the National Science Foundation and the American Association of Geographers, I’ll be heading to Cologne this August for the 32nd International Geographical Congress. The poster I’ll be presenting is a conceptual idea about the use of crowdsourcing for species distribution mapping.

At the end of each day I’ll blog about the sessions and talks that I attended, just like I did during UGI2011, just watch the tag IGC2012.

Abdulhakim Abdi

How to access the new ASTER Global DEM V2 from NASA’s REVERB-ECHO data portal

admin — Tue, 03 Apr 2012 15:24:29 +0000

The following are brief steps to assist you in ordering the ASTER Global DEM V2 data. Please refer to the tutorial at the top of the Reverb home page for more detailed instructions.

You must be a registered user to create and submit orders for ASTER GDEM V2 products.
- Refer to the Reverb Create Account tutorial for more detailed instructions on registering your contact information.
- Reverb Create Account Tutorial
  - Opens in new tab/window
Login to your account
Type aster in the Search Terms
If desired, choose spatial and/or temporal search criteria.
- Check dataset [ASTER Global Digital Elevation Model V002]
Select the “Search for Granules” button.
Accept the Data Quality Summary Disclaimer.
Select the shopping cart button for the granules you desire to order.
Select the “View Items in Cart” button.
- Reverb will report you are not able to order ASTER GDEM data if you have not logged in as a registered user.
Check the granules you desire to order.
Select the “Order Selected” button.
You may be asked to fill out address location and billing information for verification. No charge will be associated with GDEM V2 data archives.
Select the “Proceed” button.
Select the “Set” button to choose ordering options for data retrieval.
Select the data usage (required field).
Check appropriate policy agreements (required fields).
If desired, check “Use these values for all applicable order items”.
Select the “Save” button.
Select the “Proceed” button.
Select the “Submit Order” button.
Wait for email confirmation to retrieve data via FTP.
Follow email directions to retrieve data.

Landsat 5 Mission Suspended

admin — Thu, 22 Mar 2012 13:44:41 +0000

By Katrina Laygo, posted on March 21st, 2012 in Earth Observation, Quick Look & Earthzine

Landsat 5’s 28th birthday this year was marked by a suspension in operations while the USGS Flight Operations Team “continues to investigate options for theresumption of imaging.” Landsat 5’s operations were originally halted in November 2011 due to a rapidly degrading electronic component.

Landsat 5 Satellite. Credit: USGS

Since 1972, the Landsat 5 satellite, jointly managed by the U.S. Geological Survey and NASA, has provided the longest-standing record of imaging our Earth, allowing scientists to continually assess its characteristics in order to benefit society.

As part of the Landsat Program, Landsat 5 exceeded its designed life by more than 22 years. USGS Director Marcia McNutt says there’s a daunting task “of attempting to recover operations of malfunctioning, three-decade-old components in an unmanned satellite orbiting more than 400 miles above Earth.”

Acquiring imagery over the Northern Hemisphere will be the priority of Landsat 5 if its Thematic Mapper (TM) sensor continues to show no signs of improvement.

USGS is also considering focusing on the Multispectral Scanner (MSS) which collects in four bands at 79-meter resolution. If USGS is unable to restore either TM or MSS, it will decommission the satellite.

The future of the Landsat mission continues with Landsat 7, which was launched in 1999, followed by the scheduled launch of Landsat 8, also known as the Landsat Data Continuity Mission (LCDM) in January 2013.

For more information, see USGS’s Landsat Mission and NASA’s Landsat Program websites.

The Polar Geophysics Group’s new home on the Internet

admin — Fri, 16 Mar 2012 19:08:38 +0000

Our research cluster, the Polar Geophysics Group, finally has a home on the Internet. Before commencing the design of the website, I wasn’t sure whether to go for a standalone (like a dot.org) or a site embedded within the default LDEO template and attached to the LDEO URL. After consulting with the group’s PI, I decided to go for the latter for two reasons: (1) it highlights our position as a prominent group within LDEO, and (2) it enables visitors get a sense of what we do within the framework of LDEO’s mission, and (3) a standalone site would have metaphorically detached us from the wider LDEO community.

Abdulhakim Abdi

Please don’t hesitate to visit us at: www.ldeo.columbia.edu/pgg

The Approach to Open Earth Observation Data: What ESA Can Learn from NASA & USGS

admin — Tue, 06 Mar 2012 16:34:13 +0000

This post is the result of a frustrating attempt on my part to get data from the European Space Agency: I was looking for imagery from the MERIS (MEdium Resolution Imaging Spectrometer) sensor aboard Envisat, so I googled “meris data” and the top result was the ESA’s “Earthnet Online” page for MERIS that has detailed and useful information about the different data processing levels. On the top left side of the page was the header “EO Data Access” and under it “How to Apply” and “How to Access”. I was briefly taken aback and thought “I have to apply to access free data??”, I held my breath and clicked. As you can see from the screenshot to right, it succinctly says that “The free dataset includes the dataset collections available on-line. A user registration is needed for accessing the free dataset. Data access is provided in 2-3 working days after registration.” This time the words were not thought clouds over my head, I blurted out “2-3 working days?! Seriously ESA?!?”, the frustration has begun to mount.

The conceded to the fact that if I need this data, I had to play by the rules of the provider, that is just the way it is. So I click on the “user registration” link and I’m taken to yet another page that was headlined “Fast Registration”.

I smiled inwardly at the “Fast” bit of the title, did they know beforehand that their data access procedure would be anything but “Fast”? The first link is a six-page PDF that details the submission process. The fact that such a document is made available is testament to the complexity of the process. The remaining links are the usual T&Cs one gets with any data product, the fourth link is a rather useful list of which datasets are available online and which aren’t. The fifth and final link leads to the commencement of the registration process… or so I thought. In fact it leads to yet another fancy ESA page that states the following:

You’ve requested a privileged URL requiring an ESA EO-SSO logged in user. If you already have an EO-SSO account (e.g. via the Order Desk or from CARE, etc) please click the Login My Earthnet button at the top of this page. Otherwise, please register for an ESA EO-SSO account with the Register button above.

I was finally able to register. It was the standard form that emails you a verification link. I am able to log in (a brief celebration ensues). I browse and select the MERIS data product, no stumbling blocks so far. The elation was, however, short-lived. Clicking the “Get Data” button doesn’t actually get you data, but it send you an email such as the one:

In case you’re wondering, yes, clicking those links enabled me to download the data I needed. In retrospect the procedure is not was not that inconvenient, it was furstrating at the time because I was used to NASA & USGS’s much less complicated system of dispensing data, between GloVis, EarthExplorer, and the latest and greatest Reverb | ECHO downloading earth observation data cannot be any simpler and straightforward. Furthermore, NASA has twelve Distributed Active Archive Centers (DAAC) that process, archive, document, and distribute data from NASA’s past and current earth observation satellites and field measurement programs,which further simplifies the data acquisition process.

Abdulhakim Abdi

Simplicity... from NASA

On the importance of open-access data

admin — Sat, 03 Mar 2012 23:04:20 +0000

My desk during the six months of the MSc project

In the summer of 2009, between the courses of Reference Systems for Geographic Information, Applied Geostatistics, GIS Applications in Developing Countries was the course Advanced Research Methods and Skills, in which my colleagues and I had to develop proposals for our thesis projects. It was the last semester of my MSc coursework at the Institute for Geoinformatics, and my thesis topic, based on my interests, had been clear to me since the beginning of the course: distribution modeling of threatened bird species in Europe using earth observation data. Hence, the general idea was in place. However, the approach was rather murky to me. Eventually, after a lengthy literature review, I had formulated a scope and methodology, which were later approved by my advisor.

Data acquisition was subsequent on the list; finding medium resolution earth observation data was not a problem thanks to the Landsat Open Data Policy (LODP), land use and land cover data were downloadable from the EEA’s CORINE Land Cover (CLC) project, and topographic data were available from the CGIAR Consortium for Spatial Information (CGIAR-CSI). The biggest hurdle, as I later discovered, was to acquire open access bird data for the project. I scoured GBIF, eBird and the Avian Knowledge Network without luck. Albeit I was rather specific in my parameterization because I was searching for data for a particular group of birds (farmland specialists), and in a specific temporal range (the breeding season: April-June), but my scope was Europe-wide, surely there were enough records that fit my requirements?

I contacted a few agencies with requests for information, but as it turns out, not many were interested in providing data to obscure individuals conducting MSc research. Isn’t the purpose of collecting scientific data to share it with the rest of the community? Or is it (to quote a former professor of mine) to simply “data MINE”? What is the point of wrapping one’s arms around data and letting it rot in a hard disk long after they have been milked for every publishable ounce? Those were all questions floating in my head and by the end of the second month of the thesis project I was done with the literature review and ready to start processing some data. But what data? I still had nothing to work with*.

The concept behind portals such as GBIF is a noble one, but submission of records remains, as far as I know, voluntary as there is no mandate for data resulting from nationally funded projects to be made public. For instance, projects funded by the National Science Foundation of the United States are required to submit data management plans that will address the need for data from publicly-funded research to be made available to the public. Although there is an attempt in the scientific community at an international standard that discourages isolationist proprietary and commercial data “hoarding”, an equal amount of focus should be on fostering native data hosting capabilities that have an open interface. Convincing organizations to send its data to an international repository housed elsewhere is difficult, instead they be encouraged to set up their own open data infrastructure and link them to an international database(s). Alternatively, the large publishing houses (such as Elsevier, Taylor & Francis, Cambridge University Press, and so on) as well as the open access publisher like MDPI, could institute a requirement that articles accepted for publication must have associated data published in international open access repositories (such as Pangaea or GBIF). The agreement between Elsevier and Pangaea in 2010 is a step in that direction but no requirement has so far been stipulated, which means that few people will opt to make their data public.

The promotion of an equitable data sharing approach that does not discriminating against members of the community who are unable to pay for data (e.g., students, researchers in developing countries) is something that everyone should be able to agree on. After all, science is a global language and should not be confined anywhere.

In the end, I will leave you with a quote from the NSF:

Investigators are expected to share with other researchers, at no more than incremental cost and within a reasonable time, the primary data, samples, physical collections and other supporting materials created or gathered in the course of work under NSF grants. Grantees are expected to encourage and facilitate such sharing.

Abdulhakim Abdi

* I was able to find data for MSc project that fit my specifications a month later, thanks to the Catalan Ornithological Institute and Dr. Lluis Brotons.

What your favorite map projection says about you

admin — Fri, 02 Mar 2012 18:02:33 +0000

This originally appeared at www.xkcd.com

[Video] 8,000 Geographers in One Spot: AAG2012

admin — Thu, 23 Feb 2012 16:28:43 +0000

I know this is rather nerdy but this event starts tomorrow and is one of the highlights of 2012 especially because it is being held right here in NYC:

The video was made by Joseph Kersky, Esri‘s Education Manager.

Crowdsourcing Social Media to Validate Land Use and Land Cover Maps

admin — Wed, 08 Feb 2012 17:15:27 +0000

In 2011, the number of smartphone users in the US was closing in on 100 million, making up about 40% of the mobile phone market. Most late-model smartphones come embedded with megapixel-resolution cameras and GPS technology. Additionally, there are a plethora of mobile applications (apps) running location-based services (LBS) such as Twitter, Geoloqi and Foursquare. In fact, several websites, including Facebook and Google, have enabled users to perform online “check-ins” on mobile versions of their websites. To illustrate the potential of crowdsourcing, one such company (Foursquare), mapped user checkins between Halloween and Christmas of 2010. When I saw that map, the first thing that sprung to my mind was “validation”, and by that I don’t mean validating a person’s whereabouts at a particular moment in time (although this has been used by tech-savvy burglars). I am referring to validating the accuracy of land use and land cover (LULC) maps. Think about it: millions of people using LBS apps, checking in, commenting (e.g. “Just landed in JFK” or “There used to be a park here last year“), and taking photos (many with captions, e.g. “Park Avenue, facing west“). Furthermore, the recent advent of GPS-enabled point-and-shoot cameras such as Nikon’s AW100 and the Fujifilm FinePix XP150 have further expanded this opportunity. At any one time there are hundreds, if not thousands, of individuals using either their cameras or smartphones to take pictures of their surroundings. Most of the time, these photographs are posted on websites such as Flickr (which has been transformed into a social media site and contains 3.5 billion photos), Twitter’s native photo platform, Twitpic, or yfrog, allowing for spatial data-mining opportunities using an application programming interface (API). This means there is a wealth of geolocated and time-stamped, photographs and “checkins” that can be used to validate local, regional, and even global LULC maps.

Click! This geolocated & time-stamped photo can be used to validate a land use and land cover map of the area.

Having said that, this opportunity also has important limitations. For one, the positional accuracy of these consumer products often leaves a lot to be desired. In most cases users have to wait some time until the unit acquires enough satellites (or in the case of smartphones, cell towers) to provide acceptable location information. Zandbergen (2009) discusses this in detail, and concluded that A-GPS locations from the iPhone 3G had a root mean square error (RMSE) of 8.3 meters with a maximum error value of 18.5m. This means that positional accuracy of these datasets needs to adequately scrutinized prior to using them for validation purposes. Additionally, the choice of sampling unit for use in the accuracy assessment process is another factor that decides whether to use social media for validation. For instance, if a single ETM+ pixel (30m) is used as a sample unit, and considering that geometric accuracy of ETM+ is between 50 and 100m, then using the above mentioned iPhone 3G might be feasible. However, if the pixel is from a higher resolution satellite, say IKONOS (4m), with an accuracy of 4m, then data with an 8m RMSE are inadequate for validation purposes because it will adversely influence the thematic accuracy of maps.

At present, I know of just one paper (Fritz et al 2009) that specifically addresses crowdsourcing as a method to improve LULC maps. The platform presented in that paper, Geo-Wiki, is a brilliant concept that needs to be expanded, improved on and simplified further.

Abdulhakim Abdi

References

Zandbergen, P. A. (2009). Accuracy of iPhone locations: A comparison of assisted GPS, WiFi and Cellular Positioning, Transactions in GIS, 13(s1):5-26.
Fritz S., McCallum I., Schill C., Perger C., Grillmayer R., Achard F., Kraxner F., Obersteiner M. (2009). Geo-Wiki.Org: The Use of Crowdsourcing to Improve Global Land Cover. Remote Sensing, 1(3):345-354.