January 25th, 2011
I once heard, ‘In order to have a healthy planet, we need to have healthy forests’. Deforestation has been a global issue for decades. In the 1800’s and 1900’s Europe, Russia, North Africa, and the Middle East had a vast amount of deforestation, but within the past decade theses regions have stabilized and re-growth is now beginning to occur. Today the majority of deforestation has and continues to occur in the taiga and tropical regions where the vast amount of our world’s forest lives. To raise awareness on sustainable management, development, and conservation of all types of forests, the United Nations declared 2011 the International Year of the Forests.
So what needs to be done to help assess and manage our global forests and what tools do we need to get started?
Firstly, we need to have accurate, up-to-date maps of our forests. Forested areas cover roughly 30% of the world’s surface, that’s about 40 million km². The forested areas are not spread evenly throughout the world, nor is it located within the same climatic regions. With a high percentage begin spread among taiga regions (North America and Russia) and tropical regions (South America and Southeast Asia) that have a large difference in climate and environment. Mapping these regions can be extremely difficult due to rugged terrain, extreme climate and weather conditions, consistent cloud cover, and triple canopy forest. As we all know, Fugro’s GeoSAR (Dual Band IFSAR mapping system) is known for resolving these mapping challenges as well as being best suited for large are mapping.
GeoSAR’s unique technology supports the collection, analysis, assessment, and management of forests and carbon estimation on a country-wide basis. With it’s foliage penetrating technology (P-band), GeoSAR is unique in it’s ability to derive detailed accurate terrain data in the thickest forests and densest jungles. The difference between the X-band and P-band data provides important information that is used to develop value-added data sets such as land use/land cover and biomass estimates. Combined with ground truth data and satellite monitoring, this information is found to be extremely valuable for the assessment and management of our global forest.
GeoSAR not only provides the technology necessary for accurately mapping these difficult environments but also can provide value- added products found necessary for forest assessment and management when combined with satellite imagery that provide essential monitoring capabilities. Below you will find an example of biomass estimation collected over a tropical region generated from GeoSAR data. Do your part in spreading the awareness for the International Year of the Forests, and please remember ‘In order to have a healthy plant, we need to have healthy forest’. Please feel free to leave a comment or request further information!
Tags: biomass, Forests, Fugro EarthData, GeoSAR, IFSAR, p-band, panoramic mapping, radar, X-band
Posted in Innovation, Science | No Comments »
December 23rd, 2010
With the holidays right around the corner, it’s hard not to notice the severe weather situations occurring world wide. From all parts of the US and across Western Europe, heavy snow fall and freezing temperatures are fulfilling many wishes for a White Christmas this year…as well as creating havoc for Holiday travelers. As we watched the news coverage, my 6-year old turned to me and asked, "Mom, how is Santa going to find those kids’ houses under all that snow?"
That’s when I started thinking about GeoSAR’s ability to "see" through snow and ice
In early fall, GeoSAR took flight in Alaska to begin collecting data for the Alaska Statewide project. GeoSAR is a perfect candidate for mapping large remote areas with rugged terrain, cloud cover, and forest canopy. Accurate elevation data and cloud-free imagery are essential for a broad range of mapping applications in Alaska.
As the data came in, GeoSAR’s science and research team also noticed how GeoSAR’s P-band radar penetrated through the dry snow and ice to reveal the underlying rock and moraine. Although we still have to validate and quantify this capability through further analysis and ground truthing, preliminary results do seem to indicate that snow and ice penetration is in fact possible with GeoSAR. The image below provides a small glimpse of these exciting results! It is a view of a glacier in Alaska as seen through GeoSAR’s X- and P-bands.
To all of our readers, have wonderful holiday season and stay tuned for more GeoSAR news in 2011!
P-band data (left) penetrates through the snow and ice.
Tags: Alaska, GeoSAR, ice, p-band, penetration, snow
Posted in General, Innovation, Science | No Comments »
November 22nd, 2010
As mentioned a couple of weeks ago we recently exhibited at the GSDI Conference in Singapore, where the theme of the conference was “realizing spatially enabled society”. After some great discussions and reflections from some very prominent folks, like Dr. Dave Coleman, Dean of Engineering at the University of New Brunswick, who is also the new President of the GSDI, we offer that the provision of superior core data or framework data, commonly known as the base map is the first critical step in enabling society. It answers the question of “where am I?”. But more importantly, when the remote sensing technology reduces long data collection cycles by overcoming weather restrictions, it also provides timely, up-to-date information; in other words a snapshot in time that answers the question “at what point in time am I?”. Core data that delivers knowledge of the earth at a given point in time, both above and below the tree cover, powerfully enables all levels of government to make the decisions necessary to improve society.
The GeoSAR X-band imagery provides a “picture” of our world unobstructed by clouds, detailing all the surface features, spatially positioning them so that their complex relationships can easily be determined by GIS analysts and the “everyday” person alike. The GeoSAR X-band digital surface model (DSM) provides an accurate model with which to plan in 3D, a new phenomenon that has awakened society ever since the release of big budget 3D Hollywood movies and TV screens. The GeoSAR P-band imagery, for the first time, reveals the world under the trees, showing all the earth’s formations, man’s paths and all the items normally obstructed by vegetation. The GeoSAR P-band digital terrain model (DTM) completes the total 3D environment started by the X-band. It forms our world in 3D; showing us and leading us accurately and precisely.
We are enabled by answering the question “where are we?” and because GeoSAR collects data so quickly (288km2/minute), we know that the data are temporally related. This adds currency to the core data, in addition to precision and accuracy, which also answers the question “at what point in time are we?”
Our conclusions warrant debate and we would appreciate your thoughts on the role of core data and its place in “realizing spatially enabled society”.
Tags: foliage penetration, GeoSAR, GSDI 12, imagery, p-band, X-band
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November 4th, 2010
During our recent travels to Singapore as exhibitors at the GSDI conference, the weather was characteristically warm and humid, and produced heavy cloud cover every hour of every day. No surprises there. However, towards the end of our stay, the city recorded the worst smog since 2003. This was the result of farmers burning off the harvested crops on neighboring Sumatra, mixed in with the warm humid air. The smog was so dense it was difficult see from one side of the street to the other. It occurred to me how difficult it would be to obtain standard geospatial imagery in these conditions; conditions which present no problem for GeoSAR. I also couldn’t help but notice the triple-canopy foliage everywhere that hid so many core infrastructure features. Why in this day of advanced remote sensing technology should a project be severely stalled due to dense vegetation or adverse weather or atmospheric conditions? Users need to be able to obtain accurate geospatial data – both imagery and 3D terrain data – through tropical triple canopy foliage in less than ideal weather conditions. These are a few of the mapping challenges that GeoSAR has successfully overcome.
Night or day, cloudy or clear, GeoSAR collects and delivers the core datasets required to populate your NSDI. Traditional sensors need sunlight for operation, which substantially limits flying time to daylight only and then only when the angle is right, and cloudy and stormy conditions can keep sensors grounded for days, or even weeks. Even panchromatic satellite imagery fails to collect during harsh atmospheric conditions, where clouds and smog hide the earth from these high orbits. Satellite data from radar sensors, while penetrating the clouds offer a much reduced resolution in comparison to GeoSAR; and let’s remember that resolution is an important factor when determining the overall geospatial needs of any NSDI programme.
Night time, bad weather, cloud cover, tree canopy, snow…all of these conditions translate to impossible mapping mission, however GeoSAR tackles these challenges and shows that mapping the impossible is not only possible, but can be done with unprecedented speed and accuracy, anytime, anywhere.
So, are you ready to utilize the world’s largest commercial airborne remote sensing platform? Drop us a line and let us know your needs and we’ll see if we have a solution that fits.
Tags: 3D Terrain, atmospheric, cloudy, foliage, GeoSAR, geospatial data, GSDI 12, IFSAR, NSDI, Singapore, smog
Posted in General, Innovation, Public outreach | No Comments »
October 6th, 2010
GeoSAR continues to show its global reach by making a strong presence at upcoming events around the world. Fugro will be present at the 1st annual Latin American Remote Sensing (LARS) conference in Santiago, Chile October 4th- 8th and will continue the trade show trail joining forces with colleagues from Fugro’s South East Asia offices for the annual GSDI conference being held in Singapore October 19th- 22nd. At GSDI 12, Fugro will be presenting on Spatial Data Infrastructure (SDI) and the advantages GeoSAR provides as a data source in equatorial regions. So what advantages does GeoSAR provide for countries located in equatorial regions that are updating or developing their SDI?
Many countries, large and small, developed or developing, have built what are called Spatial Data Infrastructures (SDI). Geospatial data is a key component in developing a SDI. Geospatial data can be collected from a variety of airborne platforms. However environmental conditions for countries located along the equator can make this data collection process a bit difficult. Consistent cloud cover and triple canopy foliage are a few of the main factors that contribute to the difficulty in data collection. Fugro’s GeoSAR is uniquely designed to conqueror these obstacles. GeoSAR is a dual-band interferometric synthetic aperture radar (IFSAR) system. With each pass of the aircraft, GeoSAR simultaneously maps both surface features (X-band) and bare-earth terrain (P-band). X-band penetrates through the cloud cover collecting all the surface features while P-band penetrates through foliage (as well as cloud cover) collecting the bare-earth terrain. GeoSAR X- and P-band orthorectified imagery and digital elevation models contain all the information needed to produce topographic and thematic mapping at standard 1:25,000 and 1:50,000 map scale.
Please remember to stop by at learn more about Fugro’s GeoSAR and other geospatial services at LARS and GSDI 12. For more information please feel free to email or leave a comment!
Tags: dual-band IFSAR, GeoSAR, GSDI 12, Infrastructure, LARS, SDI, topographic mapping
Posted in General, Public outreach | 3 Comments »
September 13th, 2010
Our previous post focused on GeoSAR’s capabilities for producing data with exceptional precision and accuracy. As a continuation, we’re focusing this week on yet another extremely important data characteristic in the remote sensing and mapping community — resolution. For the remote sensing community, resolution is an all too familiar and important aspect that defines how the end product is delivered to the customer.
GeoSAR is truly a one-of-a-kind mapping system because it is the only existing dual-sided, single-pass interferometric IFSAR system that simultaneously delivers X-band and P-band data. However, we often forget that radar technology, in itself, is quite remarkable in its ability to see through clouds and operate at night. GeoSAR takes radar technology one giant leap further with the addition of P-band. Unlike other IFSAR systems, GeoSAR’s P-band penetrates foliage and records returns from the bare-earth, even in extremely dry terrain. P-band also penetrates below the ground surface. Such conditions make mapping virtually impossible for most optical sensors, but GeoSAR was specifically designed to handle mapping’s most difficult challenges, all while maintaining the same resolution, regardless of the flight altitude. So how does IFSAR maintain imagery resolution with increased flying height? GeoSAR’s DbIFSAR image resolution is uniquely governed by the bandwidth of the transmitted signal.
Imaging radar has two principal directions:
1) The along-track direction oriented to the flight path of the aircraft, and
2) The slant-range distance from the radar to the ground, which is oriented perpendicular to the flight path.
Resolution obtained from the along-track direction is determined by Pulse Repetition Frequency (PRF), which is the number of times the radar “flashes” per second (per antenna). For example, the PRF for GeoSAR is approximately 500 Hz, so this direction is referred to as “slow-time.” The PRF actually varies with the speed of the aircraft in order to maintain consistent ground spacing between radar pulses. The ground speed of the GeoSAR aircraft is typically 225 m/s or 440 kts, so the data’s along-track resolution equals approximately 0.45 m.
Resolution obtained from the slant-range direction corresponds with the speed of light (300,000,000 m/s), so this direction is understandably referred to as “fast-time”. Since GeoSAR uses a bandwidth of 160 MHz, the inherent resolution in the range direction is approximately 300/2*160 = 0.90 m.
If you would like to learn more about GeoSAR’s precision, accuracy, and resolution, please leave a comment or send an email.
Tags: DbIFSAR, dual-band IFSAR, GeoSAR, IFSAR, p-band, radar, Resolution
Posted in Resolution | 1 Comment »
August 26th, 2010
As a key player in the map-making business, Fugro is always engaged in discussions about precision, accuracy, and reliability standards within the geospatial marketplace. Fugro’s GeoSAR system has unique features that ensure quality standards are always met. These features include 4-look acquisition data redundancy as a primary feature of the GeoSAR dual-sided radar configuration, its large side overlap on adjacent flight lines, and its profiling LiDAR. As discussed in our previous “Ground Control” blog post on ground control on the fly.
Let’s first discuss what these quality terms mean in relation to GeoSAR. Accuracy is an absolute term, describing how close the estimated elevation (or position) at a given point is to the true elevation (or position) of that point. Precision is a relative term, describing the quality of the height difference between two points. Reliability is the ability to detect and correct measurement errors, which depends highly on the redundancy of the measurements.
For example, imagine using an old tape measure with 1/8” markings to measure the height of a table at all four corners. Suppose that the measurements are 30-2/8”, 30-1/8”, 29-7/8”, and 30-1/8” – or equivalent to an average of 30-1/8” with a precision of 1/8”. Suddenly, you discover you are off by an inch. That is accuracy. The measurements were inaccurate by about 1”. This example shows that measurements can be very precise, but not necessarily accurate, or they can be accurate, but not precise.
To prevent such errors, the GeoSAR system uses a calibration campaign to resolve systematic errors using precisely surveyed corner reflectors at known locations on a calibration site. A corner reflector is to radar what a benchmark is to photogrammetry—it provides a very precise geospatial correspondence between a radar point and a {X, Y, Z} location on the ground. This is done to ensure the GeoSAR measurements are accurate.
The precision of GeoSAR, or airborne IFSAR, depends on factors such as the aircraft altitude, amount of turbulence, the separation between flight lines, terrain slope, moisture, and other factors. In typical situations, airborne IFSAR is able to measure terrain elevation and geoposition at meter level precision. The accuracy of GeoSAR products depend on a variety of key factors, including the GPS position of the aircraft, the quality of ground control, and the accuracy of the geoid. Similar to GPS, Fugro GeoSAR elevations are measured in ellipsoidal heights and converted to orthometric heights using a geoid model. The more accurate the geoid model, the more accurate the GeoSAR orthometric height will be.
Understanding and applying these key factors is what separates Fugro’s GeoSAR services and products from other service providers. Stay tuned next week when we discuss Resolution and Posting. If you would like to continue this discussion or would like more information, please leave a comment!
Tags: Accuracy, geoid, GeoSAR, geospatial, Ground Control, IFSAR, LiDAR, Precision
Posted in Precision and Accuracy | 2 Comments »
August 4th, 2010
GeoSAR is back on the tradeshow trail! The past few weeks GeoSAR had a strong presence at the ESRI International User Conference in San Diego, California and Map Asia 2010 in Kuala Lumpur, Malaysia. At the ESRI International User Conference, Fugro EarthData’s Megan Blaskovich participated in the poster contest presenting a striking “GeoSAR in 3D” poster highlighting GeoSAR data collected over mountainous terrain in South America converted into stereo-colorized anaglyphs. The 3D anaglyphs were generated using ESRI’s PurVIEW extension for ArcGIS along with a GeoSAR digital elevation model (DEM) and orthorectified radar imagery. To say the least, the GeoSAR poster was quite the attention grabber.
Travelling half way around the world, we joined forces with colleagues from Fugro’s South East Asia offices in Kuala Lumpur, Malaysia for Map Asia 2010. Our presence was strongly felt and we were awarded Best Exhibitor at Map Asia 2010. During the conference’s technical sessions, Fugro EarthData’s Roy Hill delivered two compelling presentations on GeoSAR solutions, one on land-use and land-cover mapping, and the other on base mapping using PurVIEW in support of NSDI initiatives. The presentations highlighted GeoSAR’s advantages in equatorial regions where persistent cloud cover, triple canopy foliage, and rugged terrain, make traditional mapping solutions impossible.
In addition to the tradeshows, GeoSAR also participated in a “ground breaking” ceremony in Anchorage AK to mark the beginning of the 5-year Alaska Statewide Digital Mapping Initiative (SDMI). GeoSAR is currently wrapping up acquisition in Alaska for the first phase of the project awarded earlier this year to Dewberry through the US Geological Survey. The event was attended by over 200 representatives of the federal, state, local and tribal governments, as well as numerous members of the press. Fugro staff also took the opportunity to educate people about IFSAR and the benefits that the resulting maps offer to the state.
After wrapping up a very successful month our conference trail continues with planned stops in Africa, Europe and South America. Please feel free to request further information or continue the conversation at info@geosar.com or leave a comment!
Tags: Alaska, anaglyphs, dual-band IFSAR, ESRI User Conference, GeoSAR, Map Asia, stereo
Posted in General | No Comments »
July 13th, 2010
GeoSAR will be gracing the cover of PE&RS this month which will be distributed at the ESRI International User Conference July 12th- 16th in San Diego, CA. Be sure to pick up your copy, view the cover, and read the feature article “Topographic Mapping Using IFSAR Data in a 3D Desktop GIS Environment” written by: L.G. (Jake) Jenkins and Larry Lund.
The cover image represents a Digital Elevation Model generated from GeoSAR’s P-band radar overlaid with X and P-band orthorectified images, all in the ChromaDepth® color scheme. The orthorectified images were filtered to increase homogeneity, reduce speckling and remove artifacts. Waterways were flattened and rendered monotonic. The final images were composed into the scene using ESRI®’s ArcGIS software using a custom color pallet that allows the cooler colors to recede and warmer colors to advance on the eye when viewed using the ChromaDepth® 3-D glasses.
GeoSAR’s X and P-band orthorectified images are arranged split screen to highlight features such as terrain, agricultural fields and mangroves. P-band is located in the upper left as the X-band is located in the lower right. P-band highlights features associated with human settlements such as agricultural fields, irrigation channels, roadways and buildings, even those that may be hidden below the vegetation, whereas the mangroves appear brighter in the X-band imagery because they scatter more of the radar energy back.
GeoSAR is the world’s only dual-band, single-pass airborne interferometric SAR system. Penetrating clouds and foliage, GeoSAR simultaneously maps surface features (using x-band) and near bare-earth elevation (using P-band), making it particularly well suited for equatorial mapping.
Tags: 3D, ChromaDepth, cover, ESRI, Fugro EarthData, GeoSAR, IFSAR, PE&RS, radar
Posted in General, Uncategorized | 1 Comment »
June 21st, 2010
After receiving a significant amount of response for our metadata blog, we decided to discuss one of the most important aspects of any mapping project, ground control. Ground control refers to pre-marked or photo identifiable points on the Earth’s surface with known positions that is used either to process and rectify the raw geospatial data or to verify the accuracy of the final mapping products. Ground control networks are usually field surveyed in order to determine accurately their positions. However, other sources of accurate ground points can be used to verify and validate the accuracy of geospatial data products. Airborne LiDAR is excellent example of such sources as it provides highly accurate ground points that can be used in some instances as ground controls.
In GeoSAR mapping we typically use two types of ground control; a LiDAR profiler on the aircraft, and corner reflectors on the ground. As we fly over an area, our LiDAR profiler collects millions of 3-dimentional points (X,Y,Z) with high fidelity. These points provide a highly accurate dataset to compare and validate the GeoSAR products. Corner Reflectors, on the other hand, are deployed in the project area prior to our data collection. Corner Reflectors are targets constructed of material that is highly reflective to the radar signal. These reflectors are surveyed with a high level of accuracy and then imaged by the radar as we fly over them. They provide an easily identifiable known location in the radar data. Reflector data are used in the least-squares adjustment, removing slight offsets in the data between bands, and as another source of validation. The image below shows a radar reflector used during one of our mapping projects. You will notice that there are four sides to the reflector, allowing the reflector to be imaged from multiple sides during a single collection.
Ground control points are just one attribute of our unique GeoSAR mapping solution. If you would like to continue the conversation or receive more information please leave a comment. Stay tuned for more GeoSAR capabilities and updates!
Tags: corner reflectors, GeoSAR, Ground Control, LiDAR, radar
Posted in Ground Control | No Comments »
