Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Ground truth”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Earth resources data processor

The recent development of manned and unmanned space vehicles has brought about an almost unprecedented advance in studies concerned with remotely sensed earth observations. With this advance comes an unprecedented amount of data. The problem arises of how to efficiently analyze and compress unmanageable amounts of data into manageable amounts of useful information. A recently developed computer program is proposed as a partial solution to the above problem. The computer program is designed to determine the ground scene location and distribution of features extracted from remotely sensed earth observation data without human involvement in the data processing or a priori knowledge of ground truth. Human involvement and judgement are reserved for identification of the features presented in the compressed data.

Phillips, M. R.↗
NASA NTRS1972

Map the distribution of glaciofluvial deposits and associated glacial landforms

The author has identified the following significant results. Relatively little good usable ERTS-1 imagery has been received to date for data extraction. Of three U-2 aircraft support missions flown in Maine, only photography from the 20 September flight is cloud free and of excellent quality. Controlled local contract photography flown in August and September is of generally excellent quality. Low altitude ground truth photography is useful. The system of image and photo filing is discussed, and the limited work involving image and photo comparison is described.

Woodman, R. G.↗
NASA NTRS1972

Evaluation of ERTS imagery for spectral geological mapping in diverse terranes of New York State

The author has identified the following significant results. Preliminary visual examination of film positives of thirty ERTS-1 scenes obtained over New York State and adjacent areas indicates the following: (1) sixty percent of the imagery has a cloud cover of 70-100 percent, twenty-five percent has a cloud cover of 0-30 percent, and the remainder has a cover of 40-65 percent; (2) on the useable imagery, the spectral lines which may turn out to be geologically-linked totals as follows: spectral linears, 5200 km; broadly curved lines (spectral curvilinears), 700 km; major forest boundaries, 3100 km; areas with spectral geological fabric, 3100 sgkm. In the central and northwest Adirondacks, known lineaments and faults were subtracted from the spectral linears leaving a residue which totals 160 km in the central Adirondacks and 230 km in the northwest Adirondacks. It must be emphasized that these are spectral linears which have not yet been checked out against any ground truth except geological.

Isachsen, Y. W.↗
NASA NTRS1972

Dynamics of plankton populations in upwelling areas

There are no author-identified significant results in this report. Repeated coverage over the test site along the northwest coast of Africa showed that the structure of chlorophyll distribution is much more complicated than expected from continuous recordings. ERTS-1 data showed a very fast change in the chlorophyll distribution and it seems that also the concentration changes quickly. ERTS-1 showed on some frames offshore transportation of dust from the Sahara. All frames from Channel 7 will be arranged as a montage to derive the transportation pattern of dust. This step is important in biological aspects of interpreting ERTS-1 data, because the dissolution kinetics of eolian dust particles may influence significantly the chemistry of the surface water. Since visibility and the biochemistry of the test site off Africa are influenced by the dust transport, dust collection will be included in the ground truth program. Besides chlorophyll and other hydrographical parameters, the dust load in the test area will be measured. The collection plan is discussed along with a description of the high volume air sampler and the Anderson particle sizing head sampler to be used for the dust measurements.

Szekielda, K.↗
NASA NTRS1972

Geology of Utah and Nevada by ERTS imagery

The author has identified the following significant results. Imagery for a portion of the study area was received, catalogued for in-house availability, and examined for relevant data. Topographic, geologic, aeromagnetic, and gravity maps were gathered to form a basis of comparison. Overlay drawings were prepared indicating significant features for further study and eventual field checking. The number of significant observations appears to be very great, and it is apparent that methods of handling the acquired information for easy access, for planning field checks, and for final presentation, must be improved. The tracing of lithologic variations and contacts is readily noted on many of the images. Some of the features vary from what is shown on geological maps but the correlation, or lack of same, is still to be studied in the field and by comparison of ground truth geological maps with the specific images. Numerous lineaments, based on tonal differences, are noted in the districts, some of which extend for tens of kilometers. Several positive and negative magnetic anomalies are noted with the suggestion that the sources of the mineralizing fluids were derived from hidden intrusives.

Jensen, M. L.↗
NASA NTRS1972

Sea, ice and surface water circulation, Alaskan Continental Shelf

The author has identified the following significant results. Two cruises were conducted in Cook Inlet to obtain ground truth. Forty-seven stations during 22-23 August and 68 stations during 25-29 September 1972 were occupied and temperature, salinity, percent light transmission, and suspended load of surface waters obtained. Similar data at various depths was also obtained at selected stations. Cook Inlet is an estuary with complex mixing of river discharges and ocean water. The Upper Cook Inlet shows a gradual and systematic decrease in salinity, however, west of Kenai the mixing of waters is complex. The sediments in suspension originating at the head of the inlet generally settle out east of Kenai and Drift River. Sediment load in suspension decreased gradually from 1700 mg/1 near Anchorage to about 50 mg/1 in the Narrows. In the Lower Cook Inlet the suspended load varied between 1-10 mg/1. Surface waters with sediments in suspension and ocean water with relatively lower sediment concentration are clearly discernible in ERTS-1 images obtained during September 18, 1972 pass over Cook Inlet. The movement and mixing of these waters can also be delineated in the images.

Wright, F. F.↗
NASA NTRS1972

Utilization of ERTS-1 data to monitor and classify eutrophication of inland lakes

The author has identified the following significant results. Channel 7 is highly useful in surveying surface water in lakes, rivers, and large marshes. It is likely to miss detection of elliptically shaped bodies of 4 acres or less. Further, it is possible that the bodies are distorted and displaced because of lack of correction for sensor response time. These errors might not be critical because:(1) location accuracy is not essential to a surface water survey; and (2) an obviously distorted image is often not in error in excess of 5% The finding that Orchard Lake and other lakes in Oakland County have different densities in channels 4, 5, 6, and 7 is important because it implies that the lake wide water color average is different in the separate channels. Channels 6 and 7 were constant in tonal quality among all the lakes while channels 4 and 5 varied from lake to lake and in various parts of Orchard Lake. These findings are significant because it means that small inland lake color differences are recorded by the MSS even on a cloudy or hazy day. It also confirms that ERTS-1 is performing well enough to be used for correlation to ground truth and aircraft underflights.

Chase, P. E.↗
NASA NTRS1971

Remote sensing evaluation of the Klondike Mining District, Nevada. Part 1: Geology, photography and infrared

During August of 1970 Mission 140 was flown with the NASA P3A aircraft over the Klondike Mining District, Nevada. High quality metric photography, thermal infrared imagery, multispectral photography and multichannel microwave radiometry were obtained. Geology and ground truth data are presented and relationships of the physical attributes of geologic materials to remotely sensed data is discussed. It is concluded that remote sensing data was valuable in the geologic evaluation of the Klondike Mining District and would be of value in other mining districts.

Brennan, P. A.↗
NASA NTRS1973

Facilitating the exploitation of ERTS imagery using snow enhancement techniques

The author has identified the following significant results. EarthSat has established an effective mail-based method for obtaining timely ground truth (snow depth) information over an extensive area. The method is both efficient and inexpensive compared with the cost of a similarly scaled direct field checking effort. Additional geological information has been acquired which is not shown in geological maps in the area. Excellent quality snow-free ERTS-1 transparencies of the test areas have been received and are being analyzed.

Wobber, F. J.↗
NASA NTRS1972

Automated thematic mapping and change detection of ERTS-1 images

The author has identified the following significant results. An ERTS-1 image was compared to aircraft photography and maps of an area near Brownsville, Texas. In the coastal region of Cameron County, natural and cultural detail were identified in the ERTS-1 image. In Hidalgo County, ground truth was located on the ERTS-1 image. Haze and 50% cloud cover over Hidalgo County reduced the usefulness of multispectral techniques for recognizing crops.

Gramenopoulos, N.↗
NASA NTRS1972

An interdisciplinary study of the estuarine and coastal oceanography of Block Island Sound and adjacent New York coastal waters

The author has identified the following significant results. The synoptic repetitive coverage of the multispectral imagery from the ERTS-1 satellite, when photographically reprocessed using the state-of-the-art techniques, has given indication of spectral differences in Block Island and adjacent New England waters which were heretofore unknown. Of particular interest was the possible detection of relatively small amounts of phytoplankton prior to the occurrence of the red tide in Massachusetts waters. Preparation of spatial and temporal hydrographic charts using ERTS-1 imagery and ground truth analysis will hopefully determine the environmental impact on New York coastal waters.

Yost, E.↗
NASA NTRS1973

Automated thematic mapping and change detection of ERTS-A images

There are no author-identified significant results in this report. This investigation is concerned with the development of automated interpretation techniques for the recognition and identification of earth resources. The resources will be identified by using both multispectral and spatial signatures. Ground truth data and aircraft underflight photography will be used to train the recognition algorithms. The data processed will be RBV and MSS images acquired by ERTS-1 satellite, over six test sites located in the vicinities of: Phoenix, Arizona; Weslaco, Texas; Cascade Mountains, Washington; New Orleans, Louisiana; Salt Lake City, Utah; and Salton Sea, California. The processed data will be thematic maps of resources consisting of annotated and outlined images. The seasonal changes of hydrologic and agricultural resources will also be identified. The results are expected to be applicable to a future automatic system of resource inventory and management.

Gramenopoulos, N.↗
NASA NTRS1973

Geographic applications of ERTS-1 imagery to rural landscape change in eastern Tennessee

There are no author-identified significant results in this report. A multistage sampling experiment was conducted using low (10,000') and high (60,000') altitude aircraft imagery in comparison with orbital (560 miles) ERTS imagery. Although the aircraft data provide detailed landscape observations similar to ground truth data, they cover relatively small areas per image frame for irregular static slices of time. By comparison, ERTS provides repetitive observations in a regional perspective for broad areal coverage. Microdensitometric and computer techniques are being used to analyze the ERTS imagery for gray tone signatures, comparisons, and ultimately for landscape change detection.

Rehder, J. B.↗
NASA NTRS1973

Application of automated multispectral analysis to Delaware's coastal vegetation mapping

There are no author-identified significant results in this report. Overlay maps of Delaware's wetlands have been prepared, showing the dominant species or group of species of vegetation present. Five such categories of vegetation were used indicating marshes dominated by: (1) salt marsh cord grass; (2) salt marsh hay and spike grass; (3) reed grass; (4) high tide bush and sea myrtle; and (5) a group of fresh water species found in impounded areas built to attract water fowl. Fifteen such maps cover Delaware's wetlands from the Pennsylvania to the Maryland borders. The mapping technique employed utilizes the General Electric multispectral data processing system. This system is a hybrid analog-digital system designed as an analysis tool to be used by an operator whose own judgment and knowledge of ground truth can be incorporated at any time into the analyzing process. The result is a high speed, cost effective method for producing enhanced photomaps showing a number of spectral classes, each enhanced spectral class being representative of a vegetative species or group of species.

Klemas, V.↗
NASA NTRS1973

Effective use of ERTS multisensor data in the Great Plains

The author has identified the following significant results. It appears that identification of corn and soybeans as separate classes may not be feasible for the part of the growing season around August 15. It is hoped that at other points in the growing season separation of corn from soybeans will be possible. Visual examination of September 5 imagery indicates that later in the growing season, it is possible. The resolution of the 1:300,000 scale enlargement remained sharp enough to distinguish features important for making soil association maps. The land use pattern (range vs cultivated) was sharp as were the stream bottoms, stream valley sides, and stock ponds. The resolution of the 1:1,000,000 scale enlargement was less sharp on detail but it appears that some features could be quantitatively analyzed. Among these are the hydrologic features present such as stock ponds and the streams. It would appear that the total area of stock pond water on a frame could be measured, and, after ground truth established their average depth, the volume of water stored could be calculated and be monitored.

Myers, V. I.↗
NASA NTRS1973

Dynamics of distribution and density of phreatophytes and other arid land plant communities

The author has identified the following significant results. Ground truth measurements of plant coverage on six satellite overflight dates reveal unique trends in coverage for the five desert or semi-desert communities selected. Densitometry and multispectral additive color viewing were used in a preliminary analysis of imagery using the electronic satellite image analyzer console at Stanford Research Institute. The densitometric analysis shows promise for mapping boundaries between plant communities. Color additive viewing of a chronologic sequence of the same scene shown in rapid order will provide a method for mapping phreatophyte communities.

Turner, R. M.↗
NASA NTRS1973

Coordination and establishment of centralized facilities and services for the University of Alaska ERTS survey of the Alaskan environment

The author has identified the following significant results. Scene 1072-21173 of the Anaktuvuk Pass region of the Brooks Range, Alaska, was studied from the point of view of a resource survey for purposes of land use planning as part of the effort to develop ERTS data processing and interpretation techniques. Other data sources and surface observations were utilized to produce a resource survey of a remote and undeveloped region of Alaska. Three vegetative types are apparent: moist tundra, low brush, and high brush. Watersheds are easily defined on the multispectral imagery. Features related indirectly to economic minerals are discernible from ERTS-1 imagery supported by ground truth data. These include mountains, outwash plains and alluvial deposits, drainage patterns, lineaments and probable bedding planes. This region falls within present land class categories which are not inconsistent with the imperatives of the resources. These land class categories include native village withdrawals, regional deficiency area, national interest study area for possible inclusion in a national system, public interest areas, utility corridor, and state land selection.

Belon, A. E.↗
NASA NTRS1972

Remote sensing study of land use and sedimentation in the Ross Barnett Reservoir, Jackson, Mississippi area

This multi-year study is aimed at focusing on the recognition of sediment and other affluents in a selected area of the Ross Barnett Reservoir. The principle objectives are the determination of land use types, effect of land use on erosion, and the correlation of sediment with land use in the area. The I2S multi-band imagery was employed in conjunction with ground truth data for both water and land use studies. The selected test site contains approximately forty square miles including forest, open land, and water in addition to residential and recreational areas.

Mealor, W. T., Jr.↗