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!

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.

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!

GeoSAR Crossword Puzzle Answers

GeoSAR Crossword Puzzle

Last week, we traveled to Anchorage, Alaska, where we met up with some of our local staff and exhibited at the Alaska Surveying and Mapping Conference. It’s a place we’ve been coming back to often as Stakeholders have been working long and hard over the past couple of years to address the state’s pressing needs for accurate and up-to-date topographic mapping. Given the size, geographic location, and challenging terrain, airborne IFSAR has been deemed the ideal solution for generating accurate and detailed digital elevation data.

But elevation isn’t the only application for Alaska Stakeholders. This point was illustrated in a well-received talk by Fugro EarthData’s Steven Shaffer. In his presentation, “Airborne IFSAR Mapping in Alaska: Solutions for a Statewide DEM and Beyond,” Steve explored many additional use cases for dual-band IFSAR in particular, including those related to forestry, soil studies, and snow/ice mapping. If you weren’t able to attend the conference but are interested in learning more about what we presented, let us know and we’ll make sure to answer your information needs.

This week, it’s back to Washington, DC, International Conference on Commercial Remote Sensing! We hope to see you there.

It’s the monitoring piece where geospatial comes into play. As addressed in our last entry about the REDD initiative, several remote sensing methodologies can contribute to large-area forest carbon measurement and monitoring, each with unique benefits. This week we are taking a closer look, reviewing the top-three technologies and briefly exploring their strengths and weaknesses:

Optical imaging: Offering low-cost, repeat coverage acquisition over large project areas, satellite-based hyperspectral and multispectral imagery has shown some potential for biomass estimation. Systems with sophisticated scheduling enable around 70 percent cloud-free coverage in equatorial regions, thereby reducing weather obstacles. And while satellite is proving a good source for monitoring REDD sites in Brazil, it alone isn’t a good source for carbon measurement. For that, you need tree height data and optical imagery provides only canopy-level information.

LiDAR mapping: Foresters have long used LiDAR systems to measure forest canopy and vertical structures. As an active sensor, airborne LiDAR data can be acquired night or day, providing very dense and accurate datasets. The downside to this approach is the high cost of acquisition and processing over large areas. Satellite-based LiDAR systems may help control these costs with wide area coverage and automated processing capabilities. The Geoscience Laser Altimeter System (GLAS) on NASA’s Ice, Cloud, and Land Elevation Satellite (ICESat) is one such example. Some studies show promising results, though clouds are an issue, and so is a general lack of ground height data. So, again, LiDAR may be a technology best suited for monitoring practices.

IFSAR mapping: Low frequency, long bandwidth IFSAR is an all-weather technology that provides high foliage penetration for near bare-earth elevation data, even in dense forests. When combined with higher frequency, short bandwidth IFSAR (which provides elevations of top surfaces), it is possible to detect the heights of individual trees within a forest. That’s the beauty of GeoSAR; it offers both views of the forest simultaneously and can also be used to identify forest type. This data, combined with biomass information on individual tree species, enables efficient and accurate forest carbon content estimations.

But GeoSAR isn’t a silver bullet. Given the relative high cost of airborne acquisitions in comparison to satellite sensors, IFSAR isn’t an ideal monitoring solution. It’s role is to provide accurate baseline information from which REDD programs can be evaluated.

Fugro EarthData published an article about using dual-band IFSAR for carbon accounting in the July issue of PE&RS. It’s a good source of information about remote sensing and climate change monitoring. And, if you want to catch the latest on COP-15, here’s a live web cast of the proceedings.

Next week: COP-15 wrap-up and its implications for remote sensing. Check back then!

There’s a real-life drama playing out in the Arctic again this summer, and no, we aren’t talking about Deadliest Catch reruns on the Discovery Channel. Rather, we are referring to the drastic loss of summer sea ice in the Arctic Ocean. Recent findings from the U.S. National Snow and Ice Data Center show this year’s melting to be on par with the record setting levels of 2007. And while the full impact of these events is not yet known, the report further justifies the Arctic’s reputation as “ground zero” for climate change.

As users and providers of geospatial data, it will come as no surprise to you that remote sensing is playing a key role in these Arctic ice observations. Radar sensors are particularly well suited for such studies given the region’s temporal lack of daylight and persistent cloud cover. Acquiring data 24 hours a day and in a variety of weather conditions, radar-based imagery reveals roughness patterns in the ice that allows analysts to gauge both thickness and age.

The use of radar data for this purpose dates as far back as 1978 when NASA used its SEASAT system to monitor polar sea ice conditions. Fast forward three decades, and NASA’s innovation continues with an airborne mission this spring over Iceland and Greenland. This latest effort combined two radar bands in hopes of accurately measuring the speed, direction, and topographic height of ice caps whose sub-glacial topography has already been mapped. If successful, these data will provide researchers with better data from which to model glacial mechanics.

Fugro EarthData is also actively engaged in ice mapping research. With a science-based project scheduled for completion later this year, we aim to provide a sound basis for the use of the GeoSAR dual-band radar mapping for ice studies. If you know of other radar-based ice studies, let’s talk about them here…send us your thoughts and experiences.

Earlier this summer, Microsoft launched its revamped “Live Search” service under the name “Bing.” If you haven’t seen it—and chances are you haven’t—you should. It’s pretty cool. The fact that you may not have tried it yet (we only recently did) proves how hard it can be to introduce a new product or service offering, despite its cool factor. Generating excitement for innovation among the din of complacency is an uphill battle, but once won, the rewards are as satisfying for the provider as they are for the early adopters and mass audience who follow.

Consider the rise of Google in the 1990s and our own recent “revolution” in the remote sensing world. At about the same time Google was overturning the well established likes of Yahoo and MSN, Optech and Leica were proving the same was possible in the remote sensing industry. By replacing photogrammetrically generated DEMs with dense, accurate LiDAR-sourced DEMs, these companies and early adopters helped usher in a new wave of productivity and an expanded user base for geospatial data.

Are we now facing a similar movement with IFSAR? While IFSAR will not replace LiDAR mapping altogether, it is gaining acceptance as a cost-effective alternative for large area, small scale topographic mapping projects. Further, dual-band IFSAR is showing value for even broader applications, including oil and gas exploration and carbon accounting. And that brings us to another question: what are the keys for successfully promoting new technology in the geospatial marketplace? Is it science first or marketing first? We believe it starts with science, but what about you?