New approaches to extensive forest inventory in Western Australia using large-scale aerial photography

Biggs, P. H.; Spencer, R. D.

doi:10.1080/00049158.1990.10676076

Cited by 10 publications

(7 citation statements)

References 12 publications

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“…1989, Biggs 1990, Biggs and Spencer 1990, Spencer 1992. Results have shown the need for specialised equipment and methods to manage major problems associated with image motion, scale determination, and camera tilt for the photographs to be useful for measurements.…”

Section: Large-scale Photo-mensurationmentioning

confidence: 99%

“…The system could be implemented at reasonable cost using available expertise and equipment, including a locally based Bell 206B Jetranger helicopter (Biggs and Spencer 1990). Transverse orientation of the boom relative to the direction of flight was chosen because of its higher tolerances for camera synchronisation, providing greater latitude in the selection of cameras (Spencer 1979).…”

Section: Large-scale Photo-mensurationmentioning

confidence: 99%

“…Stereopairs of sampling photographs were obtained at a scale of 1: 1 000 using a fixed-base system consisting of twin 70 mm Vinten 492 cameras (f= 100 mm) mounted on a 7.5 metre boom attached to a helicopter (Biggs et aL 1989, Biggs andSpencer 1990). GPS was used to accurately navigate flight lines and provide data to compute aircraft ground speed by computer to facilitate automatic firing of the cameras at the pre-determined spacing of 500 metres along flight lines and to record the position of each photo sample for entry into a GIS.…”

Section: Large-scale Photo-mensurationmentioning

confidence: 99%

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Small format aerial photography: methods and achievements in Australian forestry

Spencer

1998

Australian Forestry

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Since the mid 1960s Australian forestry has benefited from small format aerial photography (SFAP) for testing new films, scales and photographic conditions; for supplementing major aerial surveys by monitoring changes on small-scale images and using this information to intensify maps, such as plantings and roads in new plantations; for achieving special effects, such as shadowless large-scale coverage to detect understorey details (e.g. disease symptoms) and for double sampling at large scales in conjunction with Global Positioning System (GPS) navigation and Geographic Information Systems (GIS) analysis to obtain quantitative data for a flexible, responsive information system. Results from early photographic and mapping trials were quickly incorporated into operational procedures which are now widely applied. Likewise, a major program utilising the special effects of large scale shadow less SFAP for disease detection has been operational for many years. However, double sampling for volume inventories has only recently been applied, in spite of trials in the 1960s. The paper outlines requirements in each of these categories and uses examples from operational programs to illustrate their application.

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Section: Large-scale Photo-mensurationmentioning

confidence: 99%

Section: Large-scale Photo-mensurationmentioning

confidence: 99%

Section: Large-scale Photo-mensurationmentioning

confidence: 99%

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Small format aerial photography: methods and achievements in Australian forestry

Spencer

1998

Australian Forestry

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“…countries with huge land areas (e.g. Spencer and Hall 1988, Biggs and Spencer 1990, Spencer et al 1997, Gillis 2001, but also elsewhere (Poso 1972, Mattila 1985, Duvenhorst 1995, Hildebrandt 1996, Anttila 1998, Pinz 1999).…”

Section: Visual Interpretationmentioning

confidence: 99%

Assessment of manual and automated methods for updating stand-level forest inventories based on aerial photography

Anttila¹

2005

Diss. For.

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Anttila, P. 2005. Assessment of manual and automated methods for updating stand-level forest inventories based on aerial photography. Dissertationes Forestales 9. 42 p. Data collection for forest planning in private forestry in Finland is based on periodic, labour-intensive, stand level field inventories. Therefore, to increase guidance for forest owners more cost-efficient methods that replace or supplement field inventories are needed so as to reallocate labour resources. In addition, for active forest owners, up-to-date information is of interest. The aim of this thesis was to test the applicability of different inventory and updating methods that are based on aerial photography for the regional forest inventory of private forests in Finland. Four approaches were chosen: 1) stand level visual interpretation of changes and simulation of stand development, 2) automatic, stand level interpretation of aerial photographs utilising nonparametric estimation, 3) automatic, photogrammetric estimation of mean height, and 4) automatic, monoscopic identification of individual trees. Approaches 1 and 2 are inventory or updating methods, while approaches 3 and 4 can be considered as components of such methods. Approach 1 was found to be appropriate for operative use for estates that have not ordered a forest plan, provided that the strict prerequisites for the inventory area are met. The accuracy of approach 2, as such, was not considered to be high enough for forest planning, but this very inexpensive method could turn out to be applicable, if its accuracy could be improved. Approach 3 was based on image matching and would be most useful as a part of other methods, like template matching in multiple images. Although only identification of trees was tested in approach 4, the applicability of whole single tree based inventory method was appraised. Relatively high costs and low accuracy limit the possibilities to use this method, in practice.

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“…The standard errors in volume estimation varied from 28-54% (Table 1). Elsewhere analytical stereoplotters have been utilised in photo-measurements (Åge 1983, Spencer and Hall 1988, Biggs and Spencer 1990, Eid and Naesset 1998. Eid and Naesset (1998) noted that standard errors in volume estimation in practical photo-inventories varied between 10.5-33.6%.…”

Section: Introductionmentioning

confidence: 99%

Updating stand level inventory data applying growth models and visual interpretation of aerial photographs

Anttila¹

2002

Silva Fenn.

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Anttila, P. 2002. Updating stand level inventory data applying growth models and visual interpretation of aerial photographs. Silva Fennica 36(2): 549-560.In this study two procedures for updating stand level inventory data were developed and tested. The development of the growing stock of 62 stands over 12 years was simulated in the MELA stand simulator with no prior information of rapid changes, such as clear-cuttings. The acceptability of the simulation was decided standwise with visual interpretation of aerial false-colour photographs. If the simulated data were not accepted, new stand attributes were assessed with photo interpretation in procedure 1. In procedure 2, on the other hand, it was possible to utilise old management proposals. In case a cutting or other operation had been proposed and it looked like the operation had been realised, the interpreters accepted the proposal. Otherwise the last implemented operation and implementation year were interpreted. In case no operation had been carried out during the updating period but the growth model updated data were not acceptable, the same stand characteristics were estimated as in procedure 1. Stands where a proposal had been accepted or an operation interpreted were later updated again in MELA so that the program simulated the operations. The Root Mean Squared Errors of stem volume were 62 and 57 m 3 per ha (34 and 30%) with procedures 1 and 2. With procedure 2 the accuracy of updating was comparable with a stand level fi eld inventory carried out in the study area. The productivity of the photo interpretation procedures was 57 and 84 ha per h, respectively, whereas the productivity of a fi eld inventory has been 3.3-5 ha per h.

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New approaches to extensive forest inventory in Western Australia using large-scale aerial photography

Cited by 10 publications

References 12 publications

Small format aerial photography: methods and achievements in Australian forestry

Small format aerial photography: methods and achievements in Australian forestry

Assessment of manual and automated methods for updating stand-level forest inventories based on aerial photography

Updating stand level inventory data applying growth models and visual interpretation of aerial photographs

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