Imaging simulation and analysis of attitude jitter effect on topographic mapping for lunar orbiter stereo optical cameras

The geometric accuracy of topographic mapping with high-resolution remote sensing images is inevita-bly affected by the orbiter attitude jitter.Therefore,it is necessary to conduct preliminary research on the stereo mapping camera equipped on lunar orbiter before launching.In this work,an imaging simulation method consid-ering the attitude jitter is presented.The impact analysis of different attitude jitter on terrain undulation is conduct-ed by simulating jitter at three attitude angles,respectively.The proposed simulation method is based on the rigor-ous sensor model,using the lunar digital elevation model(DEM)and orthoimage as reference data.The orbit and attitude of the lunar stereo mapping camera are simulated while considering the attitude jitter.Two-dimensional simulated stereo images are generated according to the position and attitude of the orbiter in a given orbit.Experi-mental analyses were conducted by the DEM with the simulated stereo image.The simulation imaging results demonstrate that the proposed method can ensure imaging efficiency without losing the accuracy of topographic mapping.The effect of attitude jitter on the stereo mapping accuracy of the simulated images was analyzed through a DEM comparison.

Utilizing Iso-Value Field Curves in Lieu of Magnetic Field Lines Amid Infinite and Parallel Electrical Wires

Building on a new model proposed recently for calculating constant electro-magnetic field values, the present article explores the electro-magnetic field configuration generated by parallel electrical wires. This imposes a reevaluation of the drawing procedure for constructing field curves with a constant field values around multiple parallel electrical conducting wires. To achieve this, we employ methods akin to those used for creating contours on topographical maps, ensuring a consistent numerical field value along the entire length of the field curves. Subsequent calculations will be conducted for scenarios where wires are not parallel.

Formation mechanism of propagated sensation along the meridians,as verified by cortical somatosensory-evoked potential topographic maps

The peripheral driver stimulating theory states that as a driver passes along a certain meridian during acupuncture; the driver provokes nerve sense devices along the meridian, resulting in the nerve impulse entering the central nervous system. Accordingly, volunteers have reported propagated sensations along the meridians （PSM）. The present study was designed to utilize a cortical somatosensory-evoked potential （CSEP） topographic map for determining whether stimulation expansion occurs in somatosensory area I when sensation was provoked in individuals with obvious PSM. The sensation was blocked by mechanical compression, and the sensation was imitated in individuals without PSM. Results revealed a red, high-potential signal in the representative area of the lower limbs in individuals with obvious PSM symptoms when the Gall Bladder Meridian （GBM） sensation passed to the head and face. This representative area was near the middle line of the CSEP topographic map, and a red, high-potential signal, which jumps over the representative area of the upper limbs, also appeared in the representative face area, which was at the external region of the CSEP topographic map. However, in individuals exhibiting no PSM, only a red high-potential signal appeared in the representative lower limb area. When Hegu （LI 4） was stimulated in individuals without PSM, an obvious evoked response appeared only in the representative upper limb area. However, when Hegu was stimulated in individuals exhibiting PSM, the response area was larger in the representative upper limb area and extended to the representative face area. When Guangrning （GB 37） was stimulated in PSM individuals, the face representation response disappeared and was confined to a foot representation of the somatosensory area I when PSM was blocked by mechanical pressure. Results suggested that mechanical compression blocked PSM, and corresponding changes were exhibited in the CSEP topographic map. These results provide compelling evidence for the hypothesis that peripheral driver stimulation is the key element in producing PSM.

SYSTEM FOR AUTOMATIC GENERALIZATION OF TOPOGRAPHIC MAPS

With the construction of spatial data infi＇astructure, automated topographic map generalization becomes an indispensable component in the community of cartography and geographic information science. This paper describes a topographic map generalization system recently developed by the authors. The system has the following characteristics： 1） taking advantage of three levels of automation, i.e. fully automated generalization, batch generalization, and interactive generalization, to undertake two types of processes, i.e. intelligent inference process and repetitive operation process in generalization; 2） making use of two kinds of sources for generalizing rule library, i.e. written specifications and cartographers＇ experiences, to define a six-element structure to describe the rules; 3） employing a hierarchical structure for map databases, logically and physically; 4） employing a grid indexing technique and undo/redo operation to improve database retrieval and object generalization efficiency. Two examples of topographic map generalization are given to demonstrate the system. It reveals that the system works well. In fact, this system has been used for a number of projects and it has been found that a great improvement in efficiency compared with traditional map general- ization process can be achieved.

Topographic Characteristics for the Geomorphologic Zones in the Northwestern Edge of the Qinghai-Tibet Plateau

Based on geomorphologic and digital elevation model(DEM) data, the topographic characteristics of the northwestern edge of the Qinghai-Tibet Plateau are analyzed. Five representative peaks are first determined according to the topographic profile maps for the ridge and piedmont lines, and then the topographic gradient characteristics are analyzed according to the representative topographic profile acquisition method.Based on the geomorphologic database data, the regions between the ridge and the piedmont lines are divided into four geomorphologic zones; and the topographic characteristics are finally analyzed for the different geomorphologic zones regions using the DEM data. The research results show that from the piedmont to the ridge, there exist four geomorphologic zones: arid, fluvial, periglacial and glacial. The arid has the lowest elevation, topographic gradient, relief and slope characteristics. The fluvial has lower elevation and the highest topographic gradient, but with lower relief and slope characteristics. With higher elevation, the periglcial has lower topographic gradient, but the highest relief and slope characteristics. The glacial has the highest elevation with higher topographic gradient, relief and slope characteristics.

Interactive Generalization on Large-Scale Topographical Map Supported by a Database Platform

This paper makes astudy on the interactive digital gener-alization, where map generalizationcan be divided into intellective reason-ing procedure and operational proce-dure, which are done by human andcomputer, respectively. And an inter-active map generalization environmentfor large scale topographic map is thendesigned and realized. This researchfocuses on: ① the significance of re-searching an interactive map generali-zation environment, ② the features oflarge scale topographic map and inter-active map generalization, ③ the con-struction of map generalization-orien-ted database platform.

Comparison of Accuracy of Two Global DEMs, and the Extracted DEM from the Topographic Map of the Tafilah Governorate

SRTM DEM （shuttle radar topographic mission digital elevation model） and ASTEMR DEM （advanced space-borne thermal emission and reflection radiometer digital elevation model） are now freely available in two resolutions： 90 m and 30 m. DEM is a computerized representation of the Earth＇s relief, and is used in many applications such as hydrology, climatology, geomorphology and ecology. There are some important differences in assessing the accuracy of digital elevation models for specific applications. The purpose of this study is to investigate the errors in digital elevation models obtained globally from DEMs 90 m, 30 m ground resolution, and the extracted DEM from a topographic map by digitized contour lines of 1：50,000 scale in a rugged mountainous region and a heterogeneous landscape, using KS （kernel smoothing） interpolation method. For validation purposes, datasets of 250-GCPs （ground control points） distributed over the study area were used to evaluate and compare the accuracy of the two global Dems and the DEM extracted from TM. The main results showed that the 30 m resolution global （DEM） is the most accurate one among the three. According to the validation results, SRTM with maximum （＋） and minimum （-） error elevation is -10_9. M, with mean deviation of KS is -0.00238667, and RMS （root-mean-square） error of 0.98, and currently the most accurate model is 30 m DEM of the study area with no significant differences compared with DEM 90 m.

The Validity of Open-Source Elevations for Different Topographic Map Scales and Geomatics Applications

This paper presents an analysis of four open-source Global Digital Elevation Models (GDEMs) and compares them on two topographic profiles (nearly flat, and hills regions) for mapping and geomatics applications. The chief intention is to investigate if GDEMs-based heights, contour intervals, slopes, and topographic profiles are valid for all map scales of topographic mapping, which constitutes a major issue in mapping activities. Two case studies, the Nile delta in Egypt and Makkah city in Saudi Arabia, have been utilized to represent flat and moderate-topography patterns. The investigated GDEMs include the most-recent released models: ASTER v.3, ACE 2, SRTMGL1 v.3, and NASADEM_HGT v.1 released in 2019 and 2020 with spatial resolutions of 1 and 3 arc seconds. Available accurate Ground Control Points (GCP) consist of 540 stations in the Nile delta and 175 stations in Makkah. Based on the available datasets in two study areas, it has been found that the accuracy of investigated GDEMs over known checkpoints ranges from ±2.5 and ±5.1 meters in the Nile delta region, while it varies between ±5.1 and ±8.0 meters in the Makkah area. That indicates that the utilization of GDEMs in topographic mapping differs significantly between flat and hilly spatial regions. Therefore, it is recommended to avoid using GDEMs for developing topographic maps of scale 1:25,000 or larger in flat regions and map scale 1:50,000 or larger in hilly regions. Additionally, the accomplished results showed that all GDEM-based slopes do not match with the actual slopes from known GCP over cross section’s length up to 30 kilometers. Thus, it is concluded that GDEMs are not the appropriate heights’ source for topographic mapping at medium and large map scales, and could not be utilized for topographic profiling in precise engineering and geomatics applications.

William Morris Davis: Father of Geomorphology or Father of Geology’s Unrecognized Paradigm Problem

An often unrecognized problem is the geology and glacial history paradigm’s inability to explain topographic map drainage system and erosional landform evidence, which means geology research studies rarely address that type of topographic map evidence. The problem originated in the late 19th century with William Morris Davis who is sometimes called the father of geomorphology and was one of the first geologists to interpret what in the late 19th century were newly available topographic maps. An 1889 Davis paper describes selected drainage system evidence observed on an advance copy of the 1890 Doylestown (Pennsylvania) topographic map and an 1892 Ward paper written after discussions with Davis describes additional selected drainage system evidence seen on the same map. Both papers fail to mention the majority of the Doylestown map’s drainage system features including most barbed tributaries, asymmetric drainage divides, and through (dry) valleys crossing major drainage divides. Had Davis used all of the map’s drainage system and erosional landform evidence he should have recognized the map evidence shows headward erosion of an east-oriented Neshaminy Creek valley captured southwest-oriented streams which headward erosion of the south-oriented Delaware River valley and its east-oriented tributary Tohickon Creek valley had beheaded. Consciously or unconsciously, Davis chose not to alert future investigators that Doylestown topographic map evidence did not support his yet-to-be-published Pennsylvania and New Jersey erosion history interpretations and instead Davis proceeded to develop and promote erosion history interpretations which the map evidence did not support.

RANDOM TERRAIN MODEL

In order to slove a realistic test problem of TF/TA algorithm, it is necessary to make a discrete terrain model. The model has adjustable roughness parameters so as to test the optimization procedure for different types of terrain. In this paper, an algorithm to generate random terrain data is given.

Artifact suppression and analysis of brain activities with electroencephalography signals

Brain-computer interface is a communication system that connects the brain with computer （or other devices） but is not dependent on the normal output of the brain （i.e., peripheral nerve and muscle）. Electro-oculogram is a dominant artifact which has a significant negative influence on further analysis of real electroencephalography data. This paper presented a data adaptive technique for artifact suppression and brain wave extraction from electroencephalography signals to detect regional brain activities. Empirical mode decomposition based adaptive thresholding approach was employed here to suppress the electro-oculogram artifact. Fractional Gaussian noise was used to determine the threshold level derived from the analysis data without any training. The purified electroencephalography signal was composed of the brain waves also called rhythmic components which represent the brain activities. The rhythmic components were extracted from each electroencephalography channel using adaptive wiener filter with the original scale. The regional brain activities were mapped on the basis of the spatial distribution of rhythmic components, and the results showed that different regions of the brain are activated in response to different stimuli. This research analyzed the activities of a single rhythmic component, alpha with respect to different motor imaginations. The experimental results showed that the proposed method is very efficient in artifact suppression and identifying individual motor imagery based on the activities of alpha component.

The existence of propagated sensation along the meridian proved by neuroelectrophysiology

Propagated sensation along the meridian can occur when acupoints are stimulated by acupuncture or electrical impulses. In this study, participants with notable propagated sensation along the me- ridian were given electro-acupuncture at the Jianyu （LI15） acupoint of the large intestine meridian. When participants stated that the sensation reached the back of their hand, reguJar nervous system action discharge was examined using a physiological recording electrode placed on the superficial branch of the radial nerve. The topographical maps of brain-evoked potential in the primary cortical somatosensory area were also detected. When Guangming （GB37） acupoint in the lower limb and Hegu （LI4） acupoint in the upper limb were stimulated, subjects without propagated sensation along the meridian exhibited a high potential reaction in the corresponding area of the brain cortical somatosensory area. For subjects with a notable propagated sensation along the meridian, the re- action area was larger and extended into the face representative area. These electrophysiological measures directly prove the existence of propagated sensation along the meridian, and the periph- eral stimulated site is consistent with the corresponding primary cortical somatosensory area, which presents a high potential reaction.

Digital Terrain Modelling Using Corona and ALOS PRISM Data to Investigate the Distal Part of Imja Glacier,Khumbu Himal,Nepal

This study used Corona KH-4A and Advanced Land Observing Satellite (ALOS) PRISM images to generate digital terrain models (DTMs) of the distal part of Imja Glacier,where a few supraglacial ponds (～0.07 km 2) expanded into the large Imja Glacier Lake (Imja Tsho,～0.91 km 2) between 1964 and 2006.DTMs and subsequently derived topographical maps with contour intervals of 1 m were created from the high-resolution images (Corona in 1964 and ALOS in 2006) in the Leica Photogrammetric Suite (LPS) platform.The DTMs and topographic maps provided excellent representation of the elevation and micro-topography of the glacier surface,such as its supra-glacial ponds/lake,surface depressions,and moraine ridges,with an error of about +/-4 m (maximum).The DTMs produced from the Corona and ALOS PRISM images are suitable for use in studies of the surface change of glaciers.The topographical maps produced from the Corona data (1964) showed that part of the dead ice in the down-glacier area was even higher than the top of the lateral moraine ridges,while the glacier surface in the up-glacier area was noticeably lower than the moraine crests.This suggests more extensive melting of glacier ice in the up-glacier area before 1964.The average lowering of the glacier surface from 1964 to 2006 was 16.9 m for the dead-ice area west of the lake and 47.4 m for the glacier surface east of the lake;between 1964 and 2002,the lake surface lowered by 82.3 m.These figures represent average lowering rates of 0.4,1.1,and 2.2 m/year for the respective areas.

The first geodetic investigation at the summit of Dome A,Antarctica

Dome A is the highest ice feature in the Antarctica, up to now, little is known about surface topography at Dome A. The first Chinese ITASE expedition was carried out from Zhongshan station to Dome A during the 1996/1997 austral summer. During the 2004/2005 austral summer, the traverse was extended to the summit of Dome A which is 1228 km from Zhongshan Station by 21 st Chinese National Antarctic Research Expedition （CHINARE）. The real-time kinematic （RTK） GPS survey was carried out in the summit of Dome A during 2004/05 austral summer. The surface to-pography of Dome A was drawn up using the kinematic double-frequency GPS data covering an area of about 70 km^2. The accuracy of the kinematic survey is in the range of 0.20 m. Precise surface topography, bedrock morphology and internal laye- ring geometry are important for the future selection of the best site for deep drilling at Dome A.

A quantitative morphometric comparison of cockpit and doline karst landforms

This study presented a quantitative comparison of cockpit and doline karst by examining the numbers and characteristics of typical types of landform entities that are developed in Guilin（Guangxi, China）, La Alianza（PR, USA）, Avalton（KY, USA）, and Oolitic（IN, USA）. Five types of landform entities were defined： isolated hill（IH）, clustered hills（CHs）, isolated sinkhole（IS）, clustered sinkholes（CSs）, and clustered hills with sinkholes（CHSs）. An algorithm was developed to automatically identify these types of landform entities by examining the contour lines on topographic maps of two cockpit karst areas（Guilin and La Alianza） and two doline karst areas（Oolitic and Avalton）. Within each specific study area, the CHSs is the least developed type yet with a larger size and higher relief. The IH and IS entities are smaller in size, lower in relief, and outnumber their clustered counterparts. The total numbers of these types of entities are quite different in cockpit and doline karst areas. Doline karst is characterized by more negative（IS and CSs） than positive（IH and IHs） landforms and vice versa for cockpit karst. For example, the Guilin study area has 1192 positive landform entities in total, which occupy 9.81% of the total study area. It has only 622 negative landform entities occupying only 3.91% of the total study area. By contrast, the doline karst in Oolitic has 130 negative while only 10 positive landform entities. The positive and negative landforms in Oolitic occupy 12.68% and 2.61% of the total study area, respectively. Furthermore, average relief and slope of the landform entities are much higher and steeper in the cockpit karst than the doline karst areas. For instance, the average slope of CHs in Alvaton is 3.90 degrees while it is 19.78 degrees in La Alianza. The average relief of CSs is 4.07 m and 34.29 m in Oolitic and Guilin respectively. Such a difference within a specific area or between the cockpit and doline karst may reveal different controls on the development of karst landscape.