Procedures for Gathering Ground Truth Information for a Supervised
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Spatial Accuracy Assessment in Natural Resources And
This file was created by scanning the printed publication. Errors identified by the software have been corrected; however, some errors may remain. Attribute and Positional Accuracy Assessment of the Murray Darling Basin Project, Australia Fitzgerald, R.W.', Ritman, K.T. & Lewis, A. Abstract: The Murray Darling Basin comprises a land area of 1,058,000 km2 covering a substantial portion of SE Australia and encompassing Australia's largest river system. A basin wide woody vegetation dataset has been assembled from LANDSAT TM imagery supplemented with aerial photography at a nominal scale of 1: 100,000. The attribute accuracy assessment method is based on a multi-stage systematic sample design. A rectangular grid is placed over the entire Murray Darling Basin dataset and at each primary sample point, a secondary grid is created formed from a square contiguous set of aerial photos. A half tone, grey scale transparency covering approximately 10km2 is generated from satellite digital imagery (LANDSAT TM) for each primary grid point at a contact scale matching the available air photos. Overprinted on this transparency are the secondary grid points as patch size sampling frames. The air photos are then visually co-registered underneath the transparency with Landcover features from the LANDSAT TM image. Attribute data (presence or absence of woody vegetation) is collected directly from the air photos for each secondary grid point at 4 different patch sizes. Positional accuracy is assessed by recording 40 or more ground control points from the 1: 100,000 map sheet containing the primary grid point. These Eastings and Northings are compared to their position in the LANDSAT TM image. -
ISPRS Journal of Photogrammetry and Remote Sensing 142 (2018) 292–300
ISPRS Journal of Photogrammetry and Remote Sensing 142 (2018) 292–300 Contents lists available at ScienceDirect ISPRS Journal of Photogrammetry and Remote Sensing journal homepage: www.elsevier.com/locate/isprsjprs The effects of imperfect reference data on remote sensing-assisted estimators T of land cover class proportions ⁎ Ronald E. McRobertsa, , Stephen V. Stehmanb, Greg C. Liknesa, Erik Næssetc, Christophe Sannierd, Brian F. Waltersa a Northern Research Station, U.S. Forest Service, Saint Paul, MN, USA b Forest and Natural Resources Management, State University of New York, Syracuse, NY, USA c Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway d Systèmes d'Information à Référence Spatiale (SIRS), Villeneuve d'Ascq, France ARTICLE INFO ABSTRACT Keywords: The gain-loss approach for greenhouse gas inventories requires estimates of areas of human activity and esti- Intepreter error mates of emissions per unit area for each activity. Stratified sampling and estimation have emerged as a popular Bias and useful statistical approach for estimation of activity areas. With this approach, a map depicting classes of Precision activity is used to stratify the area of interest. For each map class used as a stratum, map units are randomly Greenhouse gas inventory selected and assessed with respect to an attribute such as forest/non-forest or forest land cover change. Ground Gain-loss method observations are generally accepted as the most accurate source of information for these assessments but may be cost-prohibitive to acquire for remote and inaccessible forest regions. In lieu of ground observations, visual interpretations of remotely sensed data such as aerial imagery or satellite imagery are often used with the caveat that the interpretations must be of greater quality than the map data. -
Ground Truth Studies Teacher Handbook
DRAFT VER / 1.1 N GLO E B P A S L A C H E A T N U G IT E INST Ground Truth Studies Teacher Handbook © ASPEN GLOBAL CHANGE INSTITUTE 1995 GROUND TRUTH STUDIES i Printing History First U.S. Edition First Printing June 1992 Second Printing July 1993 Canadian Edition First Printing June 1994 Second U.S. Edition Third Printing June 1995 Forth Printing December 2000 Subsequent Printings by Print on Demand © 1992, 1995, 2003 Aspen Global Change Institute All rights reserved. For reproduction in whole or part, obtain permission from the— Aspen Global Change Institute 100 East Francis Street Aspen, Colorado 81611 tel 970 925 7376 fax 970 925 7097 email [email protected] homepage http://www.agci.org Printed on 100% recycled paper using soy-based inks. Contributing Authors Jesse Boyce; Susan Hassol; John Katzenberger; Martha Kirpes; Anthony Leiserowitz; William Stapp. Design and Production Kelly Alford/Words Colors Pictures. Acknowledgments The GTS Teacher Handbook is a cross-disciplinary synthesis of the talents, skills and wisdom of an international group of scientists and educators. A heartfelt thank-you to them all. The Curriculum Development Team Mr. Walter Bogan, AAAS; Dr. Cheryl Charles, Project WILD; Mr. Gregory Cox, University of Alabama/Huntsville; Dr. William Kuhn, University of Michigan; Dr. James Lawless, NASA; Dr. Milton McClaren, Simon Fraser University; Dr. William Stapp, University of Michigan; and Mr. Thomas Wagner, ERIM. Pilot Teachers Ms. Elaine Bonds, Aspen Elementary School, Aspen, CO; Ms. Vicki Clark, Mathematics & Science Center, Richmond, VA; Ms. Cheryl Cleeves, Clifford Elementary School, Redwood City, CA; Ms. -
Air Photointerpretation and Satellite Imagery Analysis Techniques for Mapping Cattail Coverage in a Northern Everglades Impoundment
Air Photointerpretation and Satellite Imagery Analysis Techniques for Mapping Cattail Coverage in a Northern Everglades Impoundment Ken Rutchey and Les Vilchek Abstract 20 wetland categories using ERDAS software. The thematic ac- Color-infrared aerial photography taken in 1991 and 1995, curacy of this 20-wetland-class image, determined by analyz- and SPOT satellite imagery taken in 1991, were utilized to ing 241 stratified random ground reference points located create cattail coverage maps for Water Conservation Area 2A using global positioning system (GPS)instruments, was 70.9 (WCAZA), an impounded portion of the remnant Everglades. percent. A final consolidation of these 20 classes to form a Cattail stands were delineated and classified using conven- 12-class image gave an overall accuracy of 80.9 percent tional air photointerpretation and digital image processing (Rutchey and Vilchek, 1994). techniques, respectively. Four interacting confounding factors The methods used in the Rutchey and Vilchek (1994) (i.e., water depth/color, impacts from fire, periphyton species study were chosen because (1)there was a need to assess the composition, and growth morphology within a single species) utility of satellite imagery for mapping Everglades wetlands; are implicated as possible elements that complicated vegeta- (2) the equipment (both software and hardware) were avail- tion classification. Photointerpretation techniques showed an able; (3) it was more economical than using photointerpre- increasing trend in cattail encroachment from 421.6 hectares tation; and (4) the results could be digitally reproduced. of monotypic cattail in 1991 to 1646.3 hectares in 1995. A Overall, the accuracy results were modest for this type of 1991 SPOT classified image appears to have overestimated digital classification. -
Urban Land Mapping from Remotely Sensed Data
M. J. JACKSON* Planning lntelligence Directorate (3) Department of the Environment London, England P. CARTER lmage Analysis Group, MPD Hanoell, Oxfordshire OX11 ORA, England T. I?. SMITH Planning Intelligence Directorate (3) Department of the Environment London, England W. G. GARDNER lmage Analysis Group, MPD Hanoell, Oxfordshire OX11 ORA, England Urban Land Mapping from Remotely Sensed Data Results suggest that the Landsat resolution is compatible with the requirement to map developed areas of 5 hectares or larger. INTRODUCTION use to which land is put in the United King- dom (UK) has not been available. Claims HE DEPARTMENT of the Environment have been made by some environmentalists T(DOE) is concerned with collecting in- that land is being destroyed by urban devel- formation on both the extent and distribution opment at an alarming rate. While the lim- ABSTRACT:All developed areas, offive hectares or above, in England and Wales were mapped using aerial photography flown in 1969. The Department of the Environment is now undertaking research and development with the Image Analysis Group, Harwell to enable the monitoring of urban growth from this base year by Landsat imagery. It is necessary, therefore, that the automated classification of urban growth from Landsat data be comparable to the aerial survey. To ensure this comparability it is necessary to quantify the differences in the classification systems and to emphasize the use of ground verification procedures. Present indications are that the Landsat resolution is compatible with the DOE'S basic requirement to map developed areas of ouer five hectares, though the capability to monitor change with the high level of accuracy required has not yet been established. -
Engineering Geology Field Manual
Chapter 15 REMOTE SENSING TECHNIQUES Introduction This chapter briefly summarizes the capabilities, limitations, and requirements of typical remote sensing techniques. Depending on the nature of the data and the objective of the study, geologic interpretation of remotely sensed data may be simple or complicated. Remote sensing is a tool that makes some tasks easier, makes possible some tasks that would otherwise be impossible, but is inappropriate for some tasks. Depending on the individual situation, remote sensing may be extremely valuable. Some remote sensing interpretations can stand on their own with confidence, but for most, establishing ground truth is essential. Imaging Systems There are three main types of imaging systems, two of which are widely used in terrestrial applications: Photographic.—Cameras and film are used. Photography provides the best spatial resolution but less flexibility in spectral data collection and image enhancement. Spatial resolution is dependent on alti- tude, focal length of lenses, and the types of film used. Spectral resolution is limited to visible and near infrared wavelengths. Electronic Spectral Sensors.— Detectors are used, usually scanners, that may have less spatial resolution than photographs but can gather spectral data over wide spectral ranges that enable a wide variety of imaging processing, mineral, and geologic identification. These remote sensing systems include satellites, such as Landsat, airborne sensors carried on aircraft, and FIELD MANUAL spectrometers carried on the ground. This type of remote sensing has several categories, including multi- spectral, hyperspectral, and imaging spectroscopy. Vidicon. – A television-type system. Vidicon systems generally are inferior to other types both spatially and spectrally. They are used mostly on space probes because of operational constraints.