Transmission-type stereo mapping micro-satellite payload and ground application system

Time series of water table depths (H t ) are predicted in space using a regionalised autoregressive exogenous variable (RARX) model with precipitation surplus (#E5 /E5# t ) as input variable. Because of their physical basis, RARX model parameters can be guessed from auxiliary information such as a digital elevation model (DEM), digital topographic maps and digitally stored soil profile descriptions. Three different approaches to regionalising RARX parameters are used. In the `direct' method (DM) #E5 /E5# t is transformed into H t using the guessed RARX parameters. In the `indirect' method (IM) the predictions from DM are corrected for observed systematic errors. In the Kalman filter approach the parameters of regionalisation functions for the RARX model parameters are optimised using observations on H t . These regionalisation functions describe the dependence on spatial co-ordinates of the RARX parameters. External drift kriging and simple kriging with varying means are applied as regionalisation functions, using guessed RARX model parameters or DEM data as secondary variables. Predictions of H t at given days, as well as estimates of expected water table depths are made for a study area of 1375 ha. The performance of the three approaches is tested by cross-validation using observed values of H t in 27 wells which are positioned following a stratified random sampling design. IM performs significantly better with respect to systematic errors than the alternative methods in estimating expected water table depths. The Kalman filter methods perform better than both DM and IM in predicting the temporal variation of H t , as is indicated by lower random errors. Particularly the Kalman filter method that uses DEM data as an external drift outperforms the alternative methods with respect to the prediction of the temporal variation of the water table depth.

A flood analysis of the Hyoja drainage basin (Gwanghwamun area) in Seoul was conducted using the XP-SWMM model, which includes 315 pipeline datas and 293 subbasins. The model was created by considering topographical factors (e.g., pipeline slope and buildings). curve number (CN) values were determined for each subbasin based on land use and detailed soil maps for estimating infiltration. Additionally, a digital terrain model (DTM) was generated using a 1:5,000 digital topographical map and survey data.In the XP-SWMM model, the evaluation of ponding varies depending on the ponding conditions (e.g., Ponding Allowed(PA), Link Spill Crest to 2D(2D), None Poning(NP)), leading to considerable differences in the calculation of hydraulic heads at the nodes. The Hyoja drainage basin, the focus of this study, features a steep slope in the upstream area and hilly terrain in the downstream, indicating potential limitations in accurately modeling flood volume.To overcome the limitations of the XP-SWMM model, the surface slope and lowlands were incorporated when establishing node conditions. Areas with a slope of less than 5% were assigned the “2D” option, whereas areas with a slope greater than 5% were assigned the “NP” condition. In addition, supplementary modeling was conducted by combining certain subbasins to assess the impact of runoff from upstream areas on downstream flooding.The flood volume analysis based on the ponding conditions under 95 mm/hr rainfall revealed that the “NP” condition tended to underestimate flood volume, while the “2D” condition tended to overestimate it by assuming ponding was present even in sloped areas. As a result, the “2D” condition was applied to basins with a surface slope of 5% or less, while the “NP” condition was applied to areas that were not lowlands. Lowlands were designated as areas with an elevation below 40.0 m, accounting for approximately 20% of the total area.When comparing the flood volume before and after merging the subbasins, the flood volume in upstream areas with a slope of 5% or more decreased, whereas the volume in the downstream Gwanghwamun area increased. This situation was attributed to runoff from the upstream basin, which added to the increase in the downstream flood volume.The study findings showed that by setting node ponding conditions considering basin slope and lowland conditions, simulating flooding events that closely resemble actual occurrences is possible. Thus, limitations of the XP-SWMM model can be overcome. Furthermore, merging subbasins has proven to be an effective approach for analyzing the interactions between upstream and downstream regions and assessing the impacts of critical flood zones. Technical decisions should reflect consideration for characteristics of the basin and topographical factors when designing a modelAcknowledgementsThis work was supported by Korea Planning & Evaluation Institute of Industrial Technology funded by the Ministry of the Interior and Safety (MOIS, Korea). [Development and Application of Advanced Technologies for Urban Runoff Storage Capability to Reduce the Urban Flood Damage / RS-2024-00415937]  

In recent years, there has been a rapid advancement in the use of unmanned aerial vehicles (UAVs) in various aspects of life, especially in the area of automated data collection. These advancements have brought about numerous possibilities. The article describes the use of an unmanned aerial vehicle, specifically the PHANTOM 4 pro, to gather remote sensing data and create digital topographic plans at a scale of 1:2000 in Phu Tho province's Thanh Son district. A method was suggested for improving the current systems for obtaining remote sensing data for cartography using UAVs. The ease of controlling the UAVs and the quality and timeliness of the data they transmit to control points confirm the value of using them to create topographic maps. In addition to UAVs, fieldwork also involves the use of the GNSS brand CHCNAV I50. The high precision GNSS system enables the camera's 3D position to be detected within a few centimeters at the time of each capture. A digital topographic map was compiled of Thanh Son district, covering 165 hectares, and processed using software such as Agisoft and Global Mapper. The digital topographic map that was produced satisfies the documentation requirements of government organizations. The maximum error in height is 4.7 cm, the error of coordinates north and east are 1.8 cm and 1.4 cm respectively. This was achieved by using 590 raster images, which had a resolution of 2.3 cm and a size of 5472x3648 pixels. Based on the findings, the map's accuracy is within an acceptable range of less than 2 cm, which is suitable for a map scale of 1:2000.

Abstract. This research examines the problem of automation of quality control of digital topographic maps at the scale 1:50 000 of the Main State Topographic Map in Ukraine for the creation and maintaining the seamless topographic database for national needs, which is located on the Geoportal to ensure the development of the National Spatial Data Infrastructure (NSDI) in Ukraine. The authors determined stages of quality control of digital topographic maps at the scale of 1:50 000 for the automation one according to ISO 19157:2013 Geographic Information – Data quality. The realized automated quality control of geodatabases of updated digital topographic maps at a scale of 1:50 000 provides high speed and quality of validation: validation of quality data elements; validation of quality metadata; validation of positional accuracy. The software package “Validate” was developed for automation quality control geodatabases of digital topographic maps at the scale of 1:50 000 using the Python programming language to verify logical consistency, compliance with the rules of topological relationships between features on the map, availability and content of metadata. The “Validate” can be used for automation quality control geodatabase for any map scale, performing setting according to the requirements of the geospatial models.

Navigation electronic map, one of the electronic maps or databases which contain spatial position geographical coordinates can be combined with spatial positioning system and guide man or means of transportation accurately to arrive from place of departure to place of destination with spatial information service function of location-based services and internet application. With the ever-increasing expansion of urban size, road construction has witnessed changes with each passing day, thus actual environment requires urban navigation electronic map strengthening geographical coverage and the accuracy of the information points. Urban navigation electronic map must possess very high accuracy, including the precision of geographic position data and accuracy of the actual ground features information. Various elements of urban navigation electronic map should also have correct topological relationships and overall connectivity, which enables each ground feature to correctly map the actual world in logic and in semantic. Urban navigation electronic map must provide complete ground features attribute information to satisfy the objective and actual requirements of searching and retrieval and navigation applications. Provincial foundation surveying and mapping is a basic and early phase project the provincial government has established with investment and with established updating mechanism. Provincial foundation surveying and mapping 3D products refer to the 1:10000 scale digital mapping products DLG, DEM, DOM. Digital line graphic (DLG) is the dataset vector of tiered storage of basic geographical elements of existing topographic maps, not only includes spatial information but also includes attribute information. Digital elevation model (DEM) is the digital collection which express ground surface relief by elevation. Digital orthoimage map (DOM) is the orthoimage data which applies digital elevation models to correct and inlay digital images, according to map sheet, clipping and generating. Provincial foundation surveying and mapping DLG adopts ArcGIS Shapefile data format, with similar scale and data format to 1:10000 scale urban navigation electronic map, which can provide vector data for navigation electronic map production to ensure the consistency of the size, layer, classification and coding, properties of the map symbol. DEM, DOM can provide data base for three-dimensional navigation digital map production. High precision, high reliability, total factors of information and updating mode of provincial foundation surveying and mapping products just meet the requirement of the accuracy, information-richness and feasibility for urban navigation electronic map. Provincial foundation surveying and mapping 3D products, being used in urban navigation electronic map production, is a direct, economical, and efficient service mode. This paper describes the control and surveying of photograph, photograph annotation, and DLG, DEM, DOM data production process of provincial foundation surveying and mapping. Road annotation, production process, topology relation and geometric expression, coordinate transformation and data format of 1:10000 scale urban navigation electronic map are also dwelt on in the paper.

With the increase of satellite communication data, the modem in the ground application system is required to have a higher codec rate and communication capacity. This paper proposes a method for implementing an ultra-high speed variable block code data encoding and decoding structure, which supports serial frame input of correlated ultra-high speed block code data, completes ultra-high speed parallel encoding and decoding, and achieves independent and stable output of ultra-high speed data serial frames. The method proposed in this paper is applicable to FPGA based ultra-high speed variable block code data encoding and decoding, compatible with various block codes such as LDPC, RS, BCH, and multi rate encoding and decoding; Adopting a parallel structure processing approach to rapidly improve the modem throughput of satellite ground application systems; The software calculates the number of parallel loop modules for highspeed data caching, drives the loading of corresponding FPGA bitstreams, quickly reconstructs FPGA encoding and decoding structures, flexibly allocates resources, and improves resource utilization.

Based on the summarization of the demands on management services of massive remote sensing images data, the status quo at home and abroad are analyzed from the following two aspects: specification demands of data management and storage organizational structure. The advantages and defects of several typical data storage centers are compared with each other, consequently, the key technologies of the management system of massive remote sensing image data in the ground application system is discussed.

Digital topographic mapping experiments were carried out based on network RTK technology using GPS/BEIDOU/GLONASS multi-constellation compatible GNSS receivers in urban obstructed environment. Operation scheme and technique flow were discussed. Experimental results show that the horizontal position and elevation of the points measured by RTK can reach 2cm and 3cm precision level respectively in open environment. RTK initialization time needs about 3-5s. While in obstructed environment, such as high building and tree shanding, the RTK initialization time needs about dozens of seconds or tens of seconds, and sometimes floating solutions or even differential solutions were obtained. The impact of dense and tall building on RTK measurement is more seriously. It is more likely to get RTK fixed solution in the south side of high building than the north side of the building.

The main objective of the study is Digital Terrain Model (DTM) generation from aerial photogrammetric data and identify and map the potential avalanche prone zones in Manali region. Avalanche is a dynamic hazardous phenomenon in the snow-bound mountainous terrain. Mapping of avalanche prone terrain is crucial to minimize the avalanche hazard. Nowadays, airborne data capturing technology, such as large-format Photogrammetry, has opened new vistas for the mapping of complex and inaccessible mountainous areas. In the present study, large format digital Photogrammetry data of 20 cm ground sample distance (GSD) have been used to generate high-resolution and accurate Digital Elevation Model and ortho-images. Digital terrain model along with its derivative terrain products and land cover map generated from land cover classification of derived ortho-photo is analyzed to locate the probable avalanche zone. The terrain characteristics, snow-pack condition and prevailing meteorological conditions are the groups of variables that influence the occurrence of avalanche. Amongst these, the terrain characteristics is the most influencing factor, and easier to map due to its stable nature along the time. Therefore advanced geo-informatics techniques have been used by mixing terrain property, Digital Elevation Model (DEM) and satellite imagery to determine the different geographical factors that affect the avalanche triggering. Also the derived information was combined in Analytic Hierarchy Process to extract a map of the avalanche prone zones in the study area standard mapping techniques as coarse-resolution data are not very appropriate for such studies.

We present a new fractal based method of generating realistic models of natural landscapes. In this paper, we describe a three-steps method that produces a terrain mesh using ridge lines and rivers drainage network. As opposed to previous methods that compute water erosion for a given terrain model --- Digital Elevation Map ---, our terrain mesh is generated constrained by a precomputed set of ridge lines and rivers network. A skeleton of a ridges and rivers network is computed and stored in a Digital Elevation Map (D.E.M.) as initial values. Then, the elevations data set is enriched using a novel interpolation method based on a Midpoint Displacement's Inverse process. Finally, a midpoint displacement subdivision is applied to interpolate the remaining elevation coordinates. The resulting terrain meshes lead to naturalistic landscape models and our method seems to be very promising. Images produced by our model are presented.

<p indent="0mm">The Chang’E-5 mission realized China’s first automatic lunar surface sampling return. The Ground Research and Application System is responsible for storing, preparing, and processing the returned lunar samples. The constructed Lunar Sample Laboratory has storage, processing, and preparation functions for the original lunar samples and is capable of long-term sample storage and processing in an environment of high-purity nitrogen on Earth. The Chang’E-5 mission returned two types of samples: scooped and drilled samples. This study developed detailed storage, preparation, and processing protocols for different types of samples. Three working stages will be carried out after the sample is returned to the Lunar Sample Laboratory, including sample processing, storage, and preparation. The detailed procedure involves unsealing the sealed packaging device, separating the scooped and drilled samples, storing the drilled and scooped samples, and preparing the samples. The primary sealed containers for scooped and drilled samples were successfully extracted via a designed unsealing process. Samples for permanent storage, backup storage, engineering display, and scientific research were obtained using the division method for scooped and drilled samples. The samples are stored in different equipments at different locations according to the designed storage method in this study. Scientific samples and some display samples were polished into sections according to the designed preparation method to ensure that the basic sample information can be obtained without destroying the original characteristics of the samples. The prepared samples will be used to analyze their physical and chemical properties and describe their basic characteristics, which can provide important information and technical support for subsequent scientific research.

Unlike most of Europe, Andalucía in southern Spain as a Mediterranean area still lacks digital maps of SOC content provided by machine learning algorithms. The wide diversity of climate, geology, hydrology, landscape, topography, vegetation, and micro-relief data as easy-to-obtain covariates facilitated the development of digital soil mapping (DSM). The purpose of this research is to model and map the spatial distribution of SOC at three depths, in an area of approximately 10000 km 2 located in Seville and Cordoba Provinces, and to use R programming to compare two machine learning techniques (cubist and random forest) for developing SOC maps at multiple depths. Environmental covariates used in this research include nine derivatives from digital elevation models (DEM), three climatic variables and finally eighteen remotely-sensed spectral data (band ratios calculated by the acquired Landsat-8 OLI and Sentinel-2A MSI in July 2019). In total, 300 soil samples from 100 points were taken (0-25 cm). The purpose of this research is to model and map the spatial distribution of SOC, in an area with approximately 10000 km2 located in Seville and Cordoba Provinces, and to compare two machine learning techniques (cubist and random forest) by R programming. The findings showed that the novel approach for integrating the indices using Landsat-8 OLI and Sentinel-2A MSI satellite data had a better result. Finally, we obtained evidence that the resolution of satellite images is more important in modelling and digital mapping.

Remote sensing and GIS technologies are very useful for mapping LULC patterns and detailing the dynamics of a certain area. The utilization of these technologies has been applied to Bodri watershed in Central Java, Indonesia. The aims of this study are to map and detect LULC changes in Bodri watershed over the last two decades (1991-2001 and 2001-2009). Three data sets of Landsat image acquired on June 28, 1991; July 1, 2001 and June 21, 2009 were used for this analysis. Image classification for mapping LULC was performed by supervised classification through the maximum likelihood method. All of the visible and infrared bands (bands 1-5 and 7) were used for the analysis. LULC change processes were then detected through post classification comparison method. Analyzing LULC changes associated to its slope and elevation were performed by overlaying the classified image with slope and elevation maps which had been extracted from digital topographic map (1:25,000). Six LULC categories were classified as forest, tree plantation, dry farming field, paddy field, settlement and water. The results show that in the period of 1991-2001 there were increases in settlement (56.22%), dry farming field (41.77%) and water (32.41%), and decrease in forest (-31.85%), tree plantation (-15.19%) and paddy field (-12.23%). While, between 2001 and 2009 increase occurred in water (34.17%), tree plantation (12.63%) and settlement (7.47%), and decrease in paddy field (26.01%), forest (-12.33%) and dry farming field (-1.14%). The changes predominantly took place in the gentle slope (0-8%) and the low elevation (0-500 m) areas. These results show that urbanization and agricultural activities have occurred in these areas. The low land and gentle slope were more widely affected by and vulnerable to human and agriculture caused LULC changes than highland and steep slope areas.

GIS based optimal impervious surface map generation using various spatial data for urban nonpoint source management

This study aims to assess habitat feature on the large-scale spawning ground of the Boreal Digging Frog Kaloula borealis in Daemyung retarding basin of Daegu, and to analyze the relationships between species abundance and meteorological factors for each habitat. Fifty-seven(57) pitfalls were installed to collect species abundance of 4 survey regions, and high-resolution satellite image, soil sampling equipment, digital topographic map, and GPS were used to develop habitat features such as terrain, soil, vegetation, human disturbance. The analysis shows that the frog is most abundant in sloped region with densely herbaceous cover in southern part of the retarding basin. In the breeding season, lowland regions, where Phragmites communis and P. japonica dominant wetlands and temporary ponds distributed, are heavily concentrated by the species for spawning and foraging. Located in between legally protected Dalsung wetands and lowland regions of the retarding basin, riverine natural levee is ecologically important area as core habitat for Kaloula borealis, and high number of individuals were detected both breeding and non-breeding seasons. Temperate- and pressure-related meteorological elements are selected as statistically significant variables in species abundance of non-breeding season in lowland and highland regions. However, in sloped regions, only a few variables are statistically significant during non-breeding season. Moreover, breeding activities in sloped regions are statistically significant with minimum temperature, grass minimum temperature, dew point temperature, and vapor pressure. Significant meteorological factors with habitat features are effectively applied to establish species conservation strategy of the retarding basin and to construct for avoiding massive road-kills on neighboring roads of the study sites, particularly post-breeding movements from spawning to burrowing areas.