airbornelasermapping.com

A reference source on an emerging technology

June 1999:     PacNet Reporter interview with with Dr. Zhekui Ma of Weyerhaeuser Paper Incorporated.

This month PacNet's intrepid North American correspondent takes a virtual visit to the dark misty woods of Federal Way, Washington to talk with Dr. Zhekui Ma, remote sensing specialist in the Timberland Information Services division of Weyerhaeuser Paper. Dr. Ma has been working with Weyerhaeuser for two years helping to define new technologies for forestry management. As Weyerhaeuser is a consumer of airborne laser data not a system operator or survey company, their perspective on this new technology and the growing industry surrounding it is of great interest. It is especially timely given the recent merger of Weyerhaeuser and MacMillan Bloedel Limited to create the leading North American forest products company. Your intrepid reporter caught up with Dr. Ma one afternoon during a recent spiritual hiatus at an ancient campsite deep, deep in the woods .....

PR: Hi-diddly-ho Dr. Ma! Thanks for letting us interrupt your quiet time. To begin with, can you give us a little historical background on Weyerhaeuser and then talk about your specific interest in airborne laser mapping?

ZM: What the .......?!? Where the ..... ?? Who are you again ...? Never mind, never mind, glad to offer any wisdom I can. To give you some idea about our background, Weyerhaeuser has owned and managed private working forests for nearly a century. Since 1900 the company has led many important developments in sustainable forestry, including long-term forest ownership, prompt reforestation, high-yield practices and protection of water, wildlife and other natural resources. Currently the Timberlands business unit of Weyerhaeuser employs 2,300 people who manage 5.3 million acres of private working forests in the United States. In addition, Weyerhaeuser Canada manages 27 million acres of publicly owned forestland through long-term licenses in western Canada. Weyerhaeuser also owns a majority interest in 193,000 acres of managed forestland in New Zealand. The company is also purchasing private grazing land in Uruguay for establishing fast-growing working forests. Obviously we are very interested in emerging technologies related to any aspects of forest management.

We have been using airborne laser data since 1996 when Airborne Laser Mapping Inc. (ALM) started their service. Since then we have been using data sets collected by ALM and Waggoner Engineering Inc. (WEI) for various engineering applications. The original data sets were collected by a commercial laser sensor (Optech ALTM 1020) and cover several of our properties in Oregon and Washington. We are currently using airborne laser mapping services from AerotecUSA and their Saab TopEye sensors.

PR: Er ..... I'm from PacNet, we have a web site on airborne laser mapping ..... Never mind. Why airborne laser mapping? What are the benefits of airborne laser mapping technology for your forestry work?

ZM: Well, we need more detailed contour maps for forest inventories and designing logging roads within harvesting areas. For resource management applications we want to characterize various parameters such as tree growth. Airborne laser mapping technology provides us with the best available elevation information in rugged terrain like the Pacific Northwest. And we like the data because it provides so much detail compared to existing survey techniques. Not only can we look at obvious things like tree height and location but also vertical profiles and crown or canopy size. We are also considering applications for the laser-derived DEMs in the area of environmental protection. A good example in this area is water quality and fish habitat. To date, Weyerhaeuser has completed 29 watershed analyses covering over 731,000 acres of its forestlands in Oregon and Washington. As a result, the company is repairing or retiring forest roads, replacing road culverts, installing and improving fish ladders, repairing stream structures, improving fish habitat, enhancing stream channels, and creating pools. Obviously accurate up-to-date topographic information is extremely useful in these endeavours.

PR: I'm sure our readers would like to know how you would compare the different services and sensors? And perhaps you could share some thoughts about what the technical limitations of airborne laser mapping are as far as you are concerned?

ZM: Well the Saab TopEye system has some features that are an advantage for our work, such as higher density data under these operating conditions and better range. But regardless of the system or service provider, airborne laser mapping offers more information and better value in comparison to any other optical sensing methods. Unfortunately it is still highly dependent upon the expertise of the people using it and doesn't always deliver on its potential. In terms of a wish list we’d like a sensor to be able to get multiple return signals and record the signal intensity for each return as well. Since we are investigating the potential of using the sensor for collecting information for forest inventories, this sort of multipurpose data is of great interest to us. We’d also like to see the data products get cheaper, more accurate and have much quicker turn around in processing time.

PR: What kind of accuracy’s and turn-around times?

ZM: For us, a reasonable technical target would be grid densities of 1-2 square feet, x,y accuracy’s of 1-2 feet and z accuracy’s of 2-3 feet. In terms of turn-around we think 2 compared to the current 4 weeks after data collection is a reasonable goal. The cost of data products is also a major obstacle. Frankly it’s too expensive right now. Of course, for now we are happy with the data sets we do get, but for most of our routine work, we still defer to photogrammetry and old survey data.

PR: Are there other mapping technologies that Weyerhaeuser is evaluating for these applications?

ZM: Oh certainly. We are also looking at radar, digital cameras and various other types of lidar (laser radar) sensors.

PR: With the large resources and access to capital that Weyerhaeuser has, why doesn’t Weyerhaeuser consider purchasing their own system?

ZM: We have decided to focus on our core business which is timber management. The cost of acquiring a dedicated instrument or managing a full-time survey program is not something we are interested in incurring.

PR: Well the sun is setting fast and that’s our cue to leave. Thank you for your time and patience! We’ll find our own way back.

ZM: Sure thing. Take care, um, PupTent?

PR: That’s PacNet.

ZM: Oh.