Session 3: Inventory and Remote Sensing
(Moderated by D. Daniels)
Contents
The
history of Relascope Production
(Benno Hesske and Gerlinde Ruthner)
An
Integrated Approach to Natural Resource Inventories: GIS, GPS and Database
Management Systems
(L. G. Arvanitis and B. Ramachandran)
Using
Real-Time Differential GPS to Establish Forest Inventory Plots
(Ray Campbell and Calvin J. Liu)
Aerial
Regeneration Surveys of Deciduous Cutblocks in Northeastern Alberta, Canada
(J. Cosco, M. Symyrozum and D. Downing)
A New
Digital Video-Rangefinding Instrument for Forest Inventory
The history of Relascope production
Benno Hesske and Gerlinde Ruthner
FOB Optik
Karolingerstrasse 45 5020 Salzburg AUSTRIA
Abstract
This presentation describes the development and production of the relascope. Included are illustrative examples of changes in the instrument's design that have taken place during the last 40 years. Demonstrated are models and prototypes of subsequent versions of the relascope. Other instruments for forest measurements and their prototypes are also demonstrated and discussed.
*Presented by Benno Hesske.
An Integrated Approach to Natural Resource Inventories
Loukas G. Arvanitis and Balaji Ramachandran
School of Forest Resources and Conservation
University of Florida
PO Box 110410 Gainesville 32611-0410 USA
Abstract
This paper deals with a conceptual model related to a multi-resource inventory of the Suwannee River Water Management District in Florida. A new temporal database model will be implemented. This model is a relational one with enhanced entity relationships between component tables. It consists of a super-class, the spatial database index, and a number of subclass component tables related through a unique identifier. The Global Positioning System (GPS) will be used to identify sample locations for periodic updates. The model will be implemented via Oracle's database server. ArcView's Theme option will be used to integrate the processed data with existing spatial data sets for further analysis. This approach will have the advantage of working with smaller sets of data as opposed to the traditional Geographic Information Systems (GIS) spatial analysis. The ultimate objective is to provide timely and cost-effective information for decision making, policy formulation, and hypotheses testing.
*Presented by Loukas G. Arvanitis.
Using Real-Time Differential GPS to Establish Forest
Inventory Plots
Ray Campbell and C. J. Liu
Department of Forestry
University of Kentucky
Lexington 40546 USA
Abstract
Settling a point on the ground such as a forest inventory plot center is called stakeout. Real-time differential GPS (RT-DGPS) stakeout employs a GPS receiver to navigate to a destination point at a known location designated by coordinates defined in a datum of choice. This process can be accomplished by using differential correction signals emitted from a geostationary satellite and is believed to achieve higher positioning precision and accuracy than autonomous GPS (A-GPS). However, this notion has not been proven under subcanopy conditions. Moreover, stakeout contains both navigation error and stakeout error which have not been concurrently investigated. This study compared stakeout precision and accuracy values derived from observations made by RT-DGPS with a telemetry link to the geostationary OmniStar satellite and by A-GPS in a hardwood forest. Results of this study showed (1) stakeout success rates for RT-DGPS and A-GPS were 44% and 100%, respectively, with failures attributed to difficulties in receiving OmniStar signals which were either blocked or attenuated by mountains and tree canopies, (2) RT-DGPS was more precise and more accurate that A-DGPS, and (3) with telemetry links established, RT-DGPS was 11 times more efficient than A-GPS.
*Presented by Ray Campbell.
Aerial regeneration surveys of deciduous cutblocks in
northeastern Alberta, Canada.
John Cosco, Mike Symyrozum, and Dave Downing
Timberline Forest Inventory Consultants
#315-10357 109 St. Edmonton T5JIN3 Canada
Abstract
In Alberta, deciduous regeneration surveys are required of forestry operators on public lands under reforestation regulations issued in 1991. These surveys involve assessments of establishment success 4 to 8 years after harvesting. Establishment surveys can be costly; plot establishment is often difficult because of poor access to harvest areas and difficult travel within cutblocks, and survey costs using ground-based plot estimation methods range from $24-28CDN/ha (approximately $5.80-$6.80USD/ac). Economies can be realized through a combined photogrammetric/ground survey approach, however. In 1998, aerial regeneration survey techniques involving a mix of aerial regeneration estimates and field plot verifications were tested. In 1999, regeneration surveys on 7200 ha (17785 ac) were completed using the most promising of the techniques tested in 1998. The 1999 aerial regeneration survey involves three steps: (1) prestratification of block areas into stocked, marginal, and not satisfactorily restocked units (2) establishment of stereo photo plots at a survey intensity according to the prestratification, using 70mm format stereo color photography acquired by a helicopter mounted dual camera photo boom with computer-controlled shutters, and (3) measurement of height and stem density from stereopairs, augmented by a program of ground verification plots established at approximately 10 percent of the aerial photo points. Findings to date are that there is no significant difference in the assessment of regeneration success between ground-based and aerial regeneration estimates. Costs of aerial regeneration surveys are, however, markedly lower at $19.00CDN/ha (approx $4.60USD/ac).
*Presented by David Downing.
A New Digital Video-Rangefinding Instrument for Forest
Inventory
Neil Clark
USDA Forest Service
Virgina Tech - 0503 Blacksburg 24061 USA
Abstract
Part of the Strategic Plan for Forest Inventory and Monitoring is an effort to use advanced technology to increase operational efficiency and effectiveness. Even though the 122,000 forested plots to be visited on the ground each cycle will likely remain the same, the time allotted continues to decrease while the amount of data to be collected increases. Individual tree elemental data related to form, volume, crown, grading, etc. is currently required for collection, with the possibility of more variables to be added. As part of the effort to use advanced technology, a new digital video-rangefinding instrument has been developed. This instrument is capable of capturing large amounts of spectral, range, and orientation data in a short period of time. A conceptual model will be presented of the photogrammetric and vision-based image processes for information extraction automation.
*Presented
by Neil Clark.
Last revised: April 6, 2000