Aircraft Photography Research Articles

Analysis of noctilucent clouds’ fields according to ground-based network and airborne photography data

The article analyzes the fields of noctilucent clouds over the territory of the Russian Federation, recorded by a ground-based network of cameras using also aircraft photography, over the two nights in June 2021. It is demonstrated that aircraft photography can significantly improve the coverage of the territory of noctilucent clouds’ probable appearance. The detected noctilucent cloud fields are compared with model regions of water vapor condensation derived from satellite measurements of temperature and water vapor mixing ratio. Practical steps are proposed for the development of aircraft observations of noctilucent clouds.

The role of progressive brittle fracture in the 1931 landslide at Dogface Rock, Katoomba

The 1931 Dogface Rock landslide in Katoomba NSW was a complex, progressive cliff collapse with a failure volume in the order of 100,000 m3 that was triggered by the extraction of remnant coal pillars from the Katoomba Colliery, about 200 m below the top of the escarpment. Although underground coal mining is generally accepted as a cause of the rockslide, previous studies have not explicitly investigated the role of progressive brittle fracture in the collapse. This paper presents an integrated study which incorporates remotely piloted aircraft photogrammetry with a discrete element method numerical investigation of the landslide, and thereby explores the role of progressive brittle fracture, and re-examines the failure mechanism and runout motion of this multi-stage landslide. Remotely piloted aircraft photography is used to build a georeferenced 3D model of the site with Structure-from-Motion photogrammetry software. A digital geotechnical mapping workflow is demonstrated to investigate the morphology of the landslide scar, extract statistics on discontinuity orientation, persistence, and spacing, and undertake trace mapping of newer brittle fractures that interacted with pre-existing high persistence joints as the landslide rupture surface developed. A series of discrete element method numerical laboratory tests are used to calibrate bonded block contact properties that reproduce laboratory scale intact rock index parameters including UCS and tensile strength. Upscaled rock block contact parameters are then applied to a cliff-scale model that investigates the progressive development of rock mass damage induced by mining. Following extraction of the remnant pillars, rock mass damage develops mostly by extensile strains that produce tension cracks. Brittle fractures propagate upwards from the mine level and eventually initiate toppling of massive sandstone slabs defined by high persistence pre-existing subvertical joints. The investigation illustrates how the integration of photogrammetry with discrete element numerical methods can be used to characterise progressive brittle failure and runout of large rock slope failures.

Identification of Mung Bean in a Smallholder Farming Setting of Coastal South Asia Using Manned Aircraft Photography and Sentinel-2 Images

Mung bean (Vigna radiata) plays an important role providing protein in the rice-based diet of the people in Bangladesh. In the coastal division of Barisal, our study area, the average farm size is less than 0.5 ha and individual fields measure about 0.10 ha. The availability of free Sentinel-2 optical satellite data acquired at a 10 m ground sampling distance (GSD) may offer an opportunity to generate crop area estimates in smallholder farming settings in South Asia. We combined different sources of in situ data, such as aerial photographs taken from a low flying manned aircraft, data collected on the ground, and data derived from satellite images to create a data set for a segment based classification of mung bean. User’s accuracy for mung bean was 0.98 and producer’s accuracy was 0.99. Hence, the accuracy metrics indicate that the random tree classifier was able to identify mung bean based on 10 m GSD data, despite the small size of individual fields. We estimated the mung bean area for 2019 at 109,416 ha, which is about 40% lower than the Department of Agricultural Extension estimates (183,480 ha), but more than four times higher than the 2019 data reported by the Bangladesh Bureau of Statistics (26,612 ha). Further analysis revealed that crop production tends to be clustered in the landscape by crop type. After merging adjacent segments by crop type, the following average cluster sizes resulted: 1.62 ha for mung bean, 0.74 ha for rice (Oryza sativa), 0.68 ha for weedy fallow and 0.40 ha for a category of other crops. This explains why 10 m GSD satellite data can be used for the identification of predominant crops grown in specific regions of South Asia.

Application of Unpiloted Aircraft in Land Resource Management of Sichuan Province

For defects of traditional aviation photography and remote sensing satellite, developing unpiloted aircraft technology for land resource management in Sichuan Province is essential for land resource administration. Unpiloted aircraft technology is a development of traditional aviation photography, which wipes out many shortages of those technologies. It has features of low cost, easy control, quick responsiveness, high processing speed, and capacity of taking high definition aviation photography. This article focuses on features, system organization, and unsolved problems of unpiloted aircraft photography system. The research team has to use knowledge in many categories to design an unpiloted aircraft system, such as artificial intelligence, aviation, topography, and information technology. Moreover, this article introduces applications of this technology in land resource management, geo-hazard prevention, mineral resource protection, and many other orientations in Sichuan Province. In addition the perspective of using unpiloted aircraft in geo-hazard prevention is analyzed and some ideal results are also introduced.

Energy- and mass-balance observations of the land–ice–ocean–atmosphere system near Barrow, Alaska, USA, November 1999–July 2002

AbstractWe present results from a comprehensive field study carried out near Barrow, Alaska, USA, designed to characterize local- to intermediate-scale sea-ice processes in the Arctic coastal zone of central importance to the annual cycle and evolution of the coastal sea ice. Included in this are the behavior of the snow cover of the ice and adjacent tundra and lake system; concurrent studies of mass balance of the sea ice and lake ice; interaction of shortwave radiation with the shore-fast ice and the adjacent land surfaces; evolution of the area coverage and distribution of the various surface types; and the resulting regional albedo values. Maximum snow depths decreased during 2000–02 from 0.38 m to 0.26 m. Ice-melt rates in 2001 were 0.05 and 0.028md–1at the top and bottom of the sea ice respectively, two to three times larger than observations from the central Arctic. Detailed surface results combined with aircraft photography were used to calculate regional albedos for the late spring and early summer of 2001. Values ranged from 0.8 for all cold snow-covered surfaces to approximately 0.4 for melting sea ice and lake ice vs 0.18 for bare tundra. Regional and surface-based values of cumulative shortwave radiation entering the ice were consistent, indicating that albedo sampling on a scale of 200m can provide a useful representation for regional sea-ice albedo.

Cumulus mergers in the maritime continent region

We examine a family of tall (up to 20 km) cumulonimbus complexes that develop almost daily over an adjacent pair of flat islands in the Maritime Continent region north of Darwin, Australia, and that are known locally as “Hectors”. Nine cases observed by a rawinsonde network, surface observations (including radiation and soil measurements), the TRMM/TOGA radar, and one day of aircraft photography are used to analyse the development, rainfall, surface energy budgets, and vertical structure of these convective systems.

Forestry Applications of NASA Remote Sensing Programs

Abstract Landsat, Skylab, and the Earth Resources Survey Program are experiment remote sensing efforts initiated by NASA since the mid-1960s. The greatest utility of Landsat data is for the separation of forest from nonforest land on a regional basis. Skylab can be used to classify general forest vegetation types. Aircraft photography from the Earth Resources Survey Program often provides as much detail as larger scale photography. Space Shuttle is a new program that will provide remotely sensed data which may help in forest management.

REMOTE SENSING APPLICATIONS IN PASTURE ANALYSIS

Photographic, optical, electronic and digital methods are available for using Landsat data in applied problems of pasture surveys at a range of scales. The most versatile technique involves three stages of analysis: satellite data, aircraft photography, and field surveys

Crop discrimination with color infrared photography: A study in Douglas County, Kansas

This study examines the feasibility of discriminating agricultural crop types with color infrared photography taken in late July in northeastern Kansas. Discrimination is based on the analysis of color measurements from the color infrared photography and automated classification employing a Bayesian decision approach. The color measurements were made with a standard spot-reading color densitometer using coarse resolutions to crudely simulate photography from spacecraft altitudes. Analysis of the three color emulsions of the infrared film, as measured by the densitometer, generally did not enable discrimination of the crop types studied in late July using the present classification technique. Comparison of the present data with other studies and data of both spacecraft and sequential aircraft photography suggest, however, that color may be used as a crop discriminant. Results are modulated by time, locale, and environment, each of which strongly influences percentage accuracy obtainable when discriminating crop types.

Aircraft Photography in the Service of Science

Aircraft Photography in the Service of Science