Systems for data processing, anaylsis and representation

Allam, Mosaad; Plunkett, Gordon

Bibliographic data

Monograph

Persistent identifier:: 1067490280

Title:: Systems for data processing, anaylsis and representation

Sub title:: ISPRS Commission II Symposium : June 6 - 10, Ottawa, Canada

Scope:: 1 Online-Ressource (XX, 530 Seiten)

Year of publication:: 1994

Place of publication:: Ottawa

Publisher of the original:: The Surveys, Mapping and Remote Sensing, Natural Resources Canada

Identifier (digital):: 1067490280

Illustration:: Illustrationen

Signature of the source:: ZS 312(30,2)

Language:: English

Additional Notes:: Erscheinungsdatum des Originals ist aus dem Copyrightjahr ermittelt.

Usage licence:: Attribution 4.0 International (CC BY 4.0)

Editor:: Allam, Mosaad; Plunkett, Gordon

Corporations:: Symposium Systems for Data Processing, Analysis and Representation, 1994, Ottawa; International Society for Photogrammetry and Remote Sensing; International Society for Photogrammetry and Remote Sensing, Commission Instrumentation for Data Reduction and Analysis; Kanada, Surveys, Mapping and Remote Sensing Sector

Adapter:: Symposium Systems for Data Processing, Analysis and Representation, 1994, Ottawa; International Society for Photogrammetry and Remote Sensing; International Society for Photogrammetry and Remote Sensing, Commission Instrumentation for Data Reduction and Analysis; Kanada, Surveys, Mapping and Remote Sensing Sector

Founder of work:: Symposium Systems for Data Processing, Analysis and Representation, 1994, Ottawa; International Society for Photogrammetry and Remote Sensing; International Society for Photogrammetry and Remote Sensing, Commission Instrumentation for Data Reduction and Analysis; Kanada, Surveys, Mapping and Remote Sensing Sector

Other corporate:: Symposium Systems for Data Processing, Analysis and Representation, 1994, Ottawa; International Society for Photogrammetry and Remote Sensing; International Society for Photogrammetry and Remote Sensing, Commission Instrumentation for Data Reduction and Analysis; Kanada, Surveys, Mapping and Remote Sensing Sector

Publisher of the digital copy:: Technische Informationsbibliothek Hannover

Place of publication of the digital copy:: Hannover

Year of publication of the original:: 2019

Document type:: Monograph

Collection:: Earth sciences

Chapter

Title:: [Wednesday, June 8, 1994]

Document type:: Monograph

Structure type:: Chapter

Chapter

Title:: [Joint ISPRS/ GIS '94 Plenary III]

Document type:: Monograph

Structure type:: Chapter

Chapter

Title:: THE USE OF GPS FOR GIS GEOREFERENCING: STATUS AND APPLICATIONS M. Elizabeth Cannon

Document type:: Monograph

Structure type:: Chapter

as small as 5cm x 5 cm. These receivers are relatively new on the market and are ideal for system integration applications where GPS is merely a component in the overall system. Most of these receivers have 5 to 8 channels which means that all the satellites which are in view may not be tracked. Receivers use algorithms based on the PDOP or the satellite elevation in order to select satellites. Tests have shown that the algorithm may affect the receiver's performance under shading conditions (McLellan et al., 1994). Another distinguishing factor regarding GPS engines is the availability of raw data to the user. Some receivers do not output the measurements, but only the internally computed positions, whereas other receivers output both the pseudorange and carrier phase data. This feature is important for system developers since raw data is usually required. The cost of the C/A code engine class of receivers is generally between $500 - $8,000 (US), depending on the performance. These receivers will play a major role in the GIS market since they can add a georeferencing component to a GIS system at relatively low cost. The second class of the receivers is the C/A code handheld type which are effectively GPS engines housed in a small, lightweight data collector. Many of these receivers are targetted at the GIS market such that the receiver has software to log attribute information in addition to positions. In the past, one of the limitations of these receivers is the achievable positioning accuracy of typically a few metres. Many manufacturers are currently developing handheld systems which can deliver sub-metre or even cm-level positions. Position and attribute information can be downloaded to a GIS system in an automated process. These receivers generally range in price from $800-$12,000 (US). For surveying applications, where cm-level accuracies are needed a full C/A code receiver is generally used. These receivers have a sophisticated user interface which allows more flexibility in the operation of the unit and the number of channels range from 8 to 12 so that all satellites in view may be tracked. Raw data is generally available to the user which may be processed by manufacturer-supplied software or alternatively by third party programs. The quality of the receiver oscillator as well as the antenna are generally higher than either the engine or handheld receivers, so that errors (i.e. measurement noise and antenna phase centre stability) will be minimized. These receivers range in cost from $12,000 to $20,000 (US) and may be used for high-end GIS applications where the achievable accuracy is important. Alternatively, 164 these receivers are often used for differential base stations in GIS applications since they have the all-in-view capability. The final class of receiver is the so-called P codeless unit which gives dual frequency carrier phase (and possibly pseudorange) data without access to the encrypted P code (i.e. the Y code). These receivers are the current state-of-the-art and are generally priced in the 35,000-45,000 (US) range. The main applications of these receivers are for high accuracy rapid static surveying, on-the- fly kinematic surveying (OTF) as well as high precision static surveying over long baseline lengths (say >50 km). Table 1: GPS Receiver Classes and Features Class General Features - low cost - 5-10 channels C/Acode - system integration required engine — - raw data may not be available - flexible architecture - manufacturer post-processing software generally not available - low-mid cost - 5 or 6 channels Handheld - may have manufacturer supplied C/Acode software for m-level accuracies receiver - may interface to GIS package - mid-range cost - 8-12 channels C/Acode - sophisticated user interface receiver - manufacturer supplied software for cm-level accuracies - premium cost - 9-12 channels - sophisticated user interface P codeless - complete system with manufacturer- receiver supplied post-processing software - dual frequency data available after GPS becomes operational - quality of L2 data may vary B Receiver hardware costs are reducing at a fast rate which is mainly driven by the increasing use of the GPS system. An interesting phenomenon that is occurring is that the spread in the cost, i.e. from the lowest to the most expensive, is growing wider. This is due to the emergence of GPS engines which are 'bare-bones' receivers as compared to the full turn-key systems that include software and extensive customer support. Figure 2 shows the trend in GPS hardware over the past several years, after McDonald (1989). 12 e oo m GPS Receiver Cost $US (000's) ER a N d 3. At Achievabl dependen: measurem phase, sin the dyna kinematic not intend however t Table 2. The table ; differentia limited by level of 1C Due to thi not depenc code tect determine code (pseu of both. Fo are used, horizontal] of the scal correlator code resol and Fentoi Standard C be achieve

Access restriction

Copyright

fullscreen: Systems for data processing, anaylsis and representation

Monograph

Chapter

Chapter

Chapter

Table of contents

Cite and reuse

Monograph

Chapter

Image

Image fragment

Citation links

Citation recommendation