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311.
Surendra Singh K. D. Sharma Nepal Singh D. N. Bohra 《Journal of the Indian Society of Remote Sensing》1988,16(4):53-56
Temporal changes in ephemeral river courses and associated flood plains, which could not be detected by Landsat MSS due to its poor spatial resolution of 80m, have been identified and mapped within 10% accuracy by Landsat TM False colour composite because of its higher spectral and spatial resolution of 30 m. Over a period of 28 years (1958–86) the river courses widened upto 1.8 times through bank erosion due to the recurring flash floods. The flash floods have also caused morphological, soil fertility and landuse changes in the associated flood plains, which could also be monitored by the Landsat TM. 相似文献
312.
J. D. Leatherdale 《The Photogrammetric Record》1994,14(83):759-769
Some of the economic and operational aspects of mapping are discussed, including the conditions that may offer air survey a competitive advantage over other methods. The financing of national mapping programmes around the world is increasingly market oriented, driven by the need to provide the end users with information that they can turn into sustainable economic growth and social progress. Despite these economic pressures, map makers seem to find their work more enjoyable and rewarding than most professionals. 相似文献
313.
C. D. Burnside 《The Photogrammetric Record》1994,14(83):769-782
The paper entitled The Photogrammetric Society Analogue Instrument Project was published in The Photogrammetric Record, 14(82): 565-582 (October 1993). It contained, as Appendix A, the entry from the Archive that dealt with the Zeiss Stereoplanigraph. This paper provides a second extract from the Archive concerned with the entries relating to the Barr & Stroud ZA1 plotter, the Williamson Multiplex equipment and the Thompson pinhole plotter. 相似文献
314.
B. D. F. Methley 《The Photogrammetric Record》1994,14(83):793-803
A case is made for the development of an inexpensive and portable data capturing unit which could be used with existing mirror stereoscopes and which could provide an accuracy sufficient for most digital map databases. The results of simulation experiments to test the accuracy of the system are presented. 相似文献
315.
316.
317.
AnnGIS: Integration of GIS and a Continuous Simulation Model for Non-Point Source Pollution Assessment 总被引:1,自引:0,他引:1
Puneet Srivastava Rick L. Day Paul D. Robillard & James M. Hamlett 《Transactions in GIS》2001,5(3):221-234
Non-Point Source (NPS) models and monitoring data are often used to evaluate management practices and develop NPS pollution control plans. Application of a dynamic NPS model requires efficient input data acquisition, storage, organization, reduction, and analysis accompanied by manipulation, interpretation, reporting, and display of model outputs. A Geographic Information System (GIS) helps extract, store, and organize input data as well as manipulate and display model outputs. This paper illustrates the development of an integrated GIS system for a continuous simulation, pollutant-loading model, AnnAGNPS ( Ann ualized AG ricultural N on- P oint S ource Pollution). The integrated system, called AnnGIS, was developed using the ArcView GIS and related program extensions. Using AnnGIS, modeling studies and management plans can be efficiently and easily developed. AnnGIS helps store, organize, and manipulate spatial and tabular data, extract spatial input parameters, develop analysis scenarios, and visualize input and output data in spatial, tabular, and graphical forms. AnnGIS is generic in nature (not limited to a particular geographic location) and can be successfully used in regions for which AnnAGNPS is designed. AnnGIS's powerful graphical user interface and reference data sets facilitate efficient and informed decision-making concerning agricultural non-point pollution control and management. 相似文献
318.
B C Sarkar B S Deota P L N Raju D K Jugran 《Journal of the Indian Society of Remote Sensing》2001,29(3):151-164
GIS. a potential tool for facilitating the generation and use of thematic information, has been applied to groundwater potentiality of the Shamri micro-watershed in Shimla Taluk. The role of various parameters, namely, drainage. lineament. lithology . slope and landuse have been emphasised for delineation of groundwater potential iones. IRS-I C IAN and LISS Ill FCC merged satellite images on 1:25000 scale and Topographic map no. 53L/4 SI together with field traverses have been used as the data source. A multi-criteria evaluation following probability weighted approach has been applied for overlay analysis that allows a linear combination of weights of each thematic map with the individual capability value. 1 he resultant map indicates a high groundwater potentiality in the flood plains, river terraces and river channels in the vicinity of the Shamri nala. Other sites of high potentiality include places showing break in slopes and criss-crossing of lineaments. 相似文献
319.
Derek D. Lichti 《GPS Solutions》2000,4(2):54-62
Kinematic differential Global Positioning System (DGPS) positioning is routinely used in industry for directly observing an
aircraft's position at each instant of photographic exposure during a photogammetric survey. A critical aspect of the subsequent
data processing is estimation of the aircraft position at the exact time of exposure. GPS measurements are acquired at a uniform
sampling rate, typically 1 Hz. The exposure times, however, do not generally coincide with these times. As a result, the exposure
station positions must be interpolated from the adjacent GPS positions. This is typically done using a low-order polynomial,
expressed as a function of time, for each coordinate dimension. However, trajectory perturbations induced by atmospheric turbulence
can render such interpolation methods ineffective.
This article will convey the results of an investigation into the use of several different interpolation models with airborne
GPS data during straight, level flight. The fundamental task of time series reconstruction will first be addressed, in which
several possible interpolation models are described. Two 10-Hz, airborne GPS data sets were collected to test the accuracy
of each model. The error properties resulting from the application of each model to these data will be presented and analyzed
in terms of time-domain statistics and frequency-domain characteristids. It will be demonstrated that interpolation error
can be significantly reduced, especially in the height dimension, through judicious choice of an interpolator. ? 2000 John
Wiley & Sons, Inc. 相似文献
320.
Evaluation of Information Loss in Digital Elevation Models With Digital Photogrammetric Systems 总被引:3,自引:0,他引:3
Y. D. Huang 《The Photogrammetric Record》2000,16(95):781-791
Information loss is caused when a surface is sampled with a finite interval, such as in the production of a digital elevation model (DEM). This information loss can become the dominant part of the error in a DEM. The ability to quantify information loss enables guidance to be provided for an appropriate choice of grid interval and better accuracy assessment for the DEM. With the use of digital photogrammetric systems, evaluation of information loss has become much easier. This paper describes three methods of evaluating information loss. An example is given of the method which is most appropriate for use with a digital photogrammetric system, based on rock cliff surface data and the VirtuoZo system. 相似文献