Home Articles The synergies between LIDAR and photogrammetry lie primarily in the areas of...

The synergies between LIDAR and photogrammetry lie primarily in the areas of software and support”


Bruce Wald
President & CEO LH Systems
Bruce Wald, President & CEO LH Systems tells about his organisation, its products and plans in digital photogrammetry and LIDAR

 

  • We would like to know more about the products & services of LH Systems, with respect to the evolution of the organisation and its entry into digital photogrammetry.

    LH Systems designs, develops and manufactures a range of products and software-based systems for the acquisition, processing, management and archiving of imagery and precise geospatial information, primarily from airborne and satellite imagery. LH Systems provide users in over 75 countries with the latest production tools for precision mapping to support engineering, telecommunications, environmental planning and other land-related information applications. Headquartered in San Diego (California USA), LH Systems has wholly owned subsidiaries in Switzerland, the United Kingdom, France, Germany, Spain, Japan and Australia as well as sales offices in Denver (Colorado, USA) and Singapore. The new Airborne LIDAR Division is located in Westford, Massachusetts, USA (near Boston).

    Product lines include airborne sensor systems (RC30 film camera, ADS40 Airborne Digital Sensor, ALS40 Airborne Laser Scanner, PAV30 gyro-stabilized mount), flight management system (ASCOT), post-processing of airborne GPS (Flykin Suite+), analytical plotters (SD2000/3000), triangulation software (ORIMA), feature collection software (PRO600), photogrammetric scanner (DSW500) and digital photogrammetric software (SOCET SET, DODGER).

    LH Systems was formed in 1997 as a joint venture between GDE Systems (now part of BAE SYSTEMS) and Leica Geosystems, following six years of fruitful cooperation between the companies centred on the sale of digital photogrammetric systems from GDE’s Helava Associates subsidiary.

    In June 2001, Leica Geosystems acquired BAE SYSTEMS’ 50% ownership of LH Systems, which became part of Leica Geosystems’ GIS & Mapping Division. With over 300 employees worldwide, the Division produces GPS-based data collectors for GIS purposes, software products to prepare data for input to GIS and the well-known ranges of hardware and software products from its ERDAS and LH Systems components.

  • Digital Photogrammetry has been the strong fort of LH, what prompted it to move into LIDAR?

    LIDAR is a natural extension of LH Systems’ business, with similar (or the same) customers and data product needs derived from the same requirements that fuel photogrammetric data acquisition. LIDAR does not replace photogrammetry. Instead, LIDAR represents a complementary technology that is well suited to certain mapping applications such as forested terrain where the same ground point often cannot be seen in multiple images. Hence LIDAR becomes one more tool for acquiring topographic data. LH Systems’ objective is to offer customers a broad product palette, consisting of a range of systems for precise data acquisition and post-processing, giving the customer the opportunity to select the sensor best suited to the characteristics of each project.

  • LH has been into Aerial Photogrammetry, what synergy do you see in entering into LIDAR through the acquisition of Azimuth?

    The synergies that exist between LIDAR and photogrammetry lie primarily in the areas of software and support. LH Systems has terrific experience in helping photogrammetry customers achieve high productivity through offerings such as our digital photogrammetry software. This background can provide a substantial platform from which to develop LIDAR ground processing software enhancements to satisfy the specific demands of LIDAR data users.

    Historically, the developers of LIDAR systems have focussed on the instrument itself and achieving maximum performance from it. This has left the task of identifying an optimal software solution for LIDAR data processing squarely on the shoulders of the user community. In an expanding LIDAR market where we see smaller firms starting to play an increasingly important role, there is a distinct need for more highly integrated ground processing solutions. LH Systems has been providing these kinds of solutions for a long time in the photogrammetry market and this experience can directly bear on solutions in LIDAR processing. For instance, stereo editing and breakline generation in large digital elevation models (DEMs), techniques used in photogrammetry can readily be applied to LIDAR data as well.

  • What is the future prospect of LIDAR in developing economies?

    Most developing economies have a big focus on infrastructure improvements such as transmission lines, pipelines, roadways. All these are ideal, “corridor” applications for LIDAR, which can generate DEMs with very high density. As with many technologies, developing economies have the choice between conventional and new technologies when purchasing new equipment. In many other industries, developing economies have “leap-frogged” over conventional technologies and jumped right into the newer technology. This sort of situation creates a terrific opportunity for LIDAR as well as the ADS40 as both are candidate technologies, depending on the specific need.

  • What impacts do you foresee in the aerial photography market with high-resolution satellite imageries coming?

    If you consider the ground pixel sizes of unclassified satellite imagery today, it is clear that aerial photography offers higher resolution. That is not to say that satellite imagery isn’t impressive – it is, and it offers substantial advantages in certain applications. Of course, satellites can cover a lot more territory, though the high-resolution sensors have narrow fields of view. Based on the cost of putting a high-resolution satellite into space, one could very well buy a large fleet of conventional aircraft and provide equivalent coverage with better resolution and accuracy. Keep in mind that the spaceborne system has to look through hundreds of kilometers of space and atmosphere to record the same terrain that a conventional aircraft flies 2-6 km above. Undoubtedly, space-based imagery will continue to improve, but I think it will be a while before it takes significant market share away from conventional photogrammetry. Despite this assessment of the current situation, we at LH Systems, are enthusiastic about the combination of high-resolution satellite imagery with data from aerial film cameras, airborne digital sensors and LIDAR.

  • There are talks of Aerial Photography along Laser Mapping from a common aircraft simultaneously. What benefits do you think this service will offer? Do you foresee any upcoming “Killer App”?

    The combination of aerial photography and LIDAR is particularly potent. You can imagine the benefits of high-resolution imagery and a dense LIDAR-generated DEM. DEMs have long been used to assist in the orthorectification of aerial photography. The LIDAR DEM tends to be much denser that those available through current sources. This potentially leads to more accurate orthorectification. Our customers definitely understand this. In fact, 90% of our LIDAR customers combine LIDAR and some form of imagery, using either conventional film or medium-resolution digital framing cameras. In these cases, the user enjoys the benefit of high spatial resolution from the imagery and a very accurate, dense DEM from the LIDAR system. The imagery can be used to add breaklines to the LIDAR data, and the LIDAR data provides the fundamental DEM density.

    Perhaps this combination of LIDAR and imagery offers unique opportunities for the kind of “Killer App” you refer to. But remember – the permutations and combinations of scenarios for mapping in any particular scenario are almost infinite – there is no single “Killer App” or silver bullet. Note the incompatibility between the 24 hours per day that LIDAR can be flown and the much narrower window of aerial photography. Also, typical flying heights for LIDAR tend to be lower than for photography. There are significant operational issues in the future. Will an aerial camera and a LIDAR unit occupy the same or different holes in the floor of the aircraft? Though the LH Systems ALS40 Airborne Laser Scanner offers much the same swath width as an aerial film camera with a six-inch (15 cm) lens, this is not the case for LIDAR systems in general. We have to think about the future, when the benefits of a totally integrated imagery/LIDAR solution may be available and the industry will be able to explore new benefits.

  • Can we expect quality Laser Mapping from higher altitudes (presently said to be 1200-2000 metres) while preserving the vertical accuracy? Just extending to a flight of imagination, can we have Laser Mapping from Satellites?

    To answer your first question, the ALS40 is already proven at altitudes to 6100 metres AGL (above ground level), though most customers are flying at altitudes of 2000–3000 metres AGL to deliver data with 15 cm vertical accuracy. Maintaining those accuracies at higher altitudes requires using increasingly sophisticated and expensive components, particularly IMUs.

    There is also a general trade-off between altitude and laser design – the higher you fly, the more laser power you need. Also, the higher altitude implies a desire for a wider swath at the same point density on the ground that you currently get from an aircraft platform. At some point you start needing a jet aircraft to work effectively at those altitudes, as well as providing the increased payload and power capabilities. Under these circumstances, it is currently more cost-effective to fly multiple aircraft, not to mention the fact that aircraft can fly under the clouds. As for satellite-based LIDAR, this has already been demonstrated on the NASA Space Shuttle, on the SLA (Shuttle Laser Altimeter) programme. It works in principle, but the main technical issue becomes laser footprint. Even with very precise laser optics, the footprint of the laser pulse might be hundreds of metres in diameter by the time it hits the ground. This would create limitations on spatial resolution as well as vertical accuracy issues on non-flat terrain for any space-based LIDAR system. It’s still hard to beat the lesser limitations of an aircraft flying at ‘low’ altitudes of 6 kilometres or less.