{"title":"Motion compensation for ASTOR long range SAR","authors":"John S. A. Hepburn, C. Doyle","doi":"10.1109/PLANS.1990.66178","DOIUrl":"https://doi.org/10.1109/PLANS.1990.66178","url":null,"abstract":"The United Kingdom Ministry of Defence is conducting a long range synthetic aperture radar (SAR) technology demonstrator programme (TDP) in support of their airborne stand-off radar programme. A major goal is to develop a high-resolution airborne SAR with both strip map and spotlight modes. To attain the image quality objectives of the project, it is essential that very accurate motion compensation be applied to the radar returns to reduce image degradation, caused by spurious antenna phase center motion, to acceptable levels. The SAR motion compensation system (SARMC) includes a master inertial navigation system located near the center of mass of the host aircraft and a slaved strapdown inertial measurement unit mounted on the back of the radar antenna, as well as Doppler velocity and barometric and radar altimeters. The performance of the SARMC has been evaluated both by analysis and computer simulation. These evaluations accounted for all major system error sources, including errors associated with sensors, transfer alignment, and computation, with the system operating in an environment of moderate atmospheric turbulence. Results from these evaluations are presented.<<ETX>>","PeriodicalId":156436,"journal":{"name":"IEEE Symposium on Position Location and Navigation. A Decade of Excellence in the Navigation Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122202311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ashtech XII GPS technology","authors":"J. Ashjaee","doi":"10.1109/PLANS.1990.66175","DOIUrl":"https://doi.org/10.1109/PLANS.1990.66175","url":null,"abstract":"Several enhancements of GPS (Global Positioning System) technology are presented, including new data processing algorithms, enhanced application techniques, more hardware capabilities, and reduction in size and power consumption. The use of Doppler measurements for instantaneous (every one second) stationary position fixes is introduced. This technique has the potential of reducing the effect of selective availability in static point positioning. It is shown that the combination of Doppler and code phase measurements can provide two-dimensional deterministic static position fixes (and time) with only two satellites. It can also provide three-dimensional position fixes (and time) with three satellites. The proposed techniques expand the usage of GPS in areas with low satellite visibility and in the interim period while the GPS satellite constellation is not complete. The notion of multiple ramp smoothing of code phase with integrated Doppler is introduced. The results of implementation of this technique in Ashtech XII receivers for real-time differential GPS is given. Minimizing the errors in the use of GPS for aerial photogrammetry applications is discussed. A new technique implemented in Ashtech XII GPS is presented. A new generation of GPS receiver (Ashtech M-XII) is introduced. It is capable of performing precision survey, navigation, and time transfer. The 12-channel receiver uses a higher level of hardware integration. The results of Ashtech XII dual frequency receivers on the FGCC (Federal Geodetic Control Committee) test network are presented.<<ETX>>","PeriodicalId":156436,"journal":{"name":"IEEE Symposium on Position Location and Navigation. A Decade of Excellence in the Navigation Sciences","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122897238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The automated Loran-C coverage diagram generator","authors":"J. Catlin, D. Foulis, G. Noseworthy, B. Cairns","doi":"10.1109/PLANS.1990.66222","DOIUrl":"https://doi.org/10.1109/PLANS.1990.66222","url":null,"abstract":"The preliminary details of an automated system developed for generating and archiving Loran-C coverage diagrams are presented. A coverage diagram is a graphical representation of the geographical area inside of which a Loran-C receiver can function within specified limits. The automated Loran-C coverage diagram (ALCDG) generator is a PC-based software system that quickly computes and displays estimated service areas for existing and proposed Loran-C chains. This system can generate a coverage diagram for a proposed chain in under ten minutes, including the time needed to enter station parameters and draw the map. The system is based on existing methods for diagram generation but has been modified to improve the speed and accuracy of the process. The ALCDG has gone through several periods of design review and testing, including extensive testing of the man-machine interface and the technical model.<<ETX>>","PeriodicalId":156436,"journal":{"name":"IEEE Symposium on Position Location and Navigation. A Decade of Excellence in the Navigation Sciences","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114205429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ring laser gyro applications for tactical missiles: the Army TACMS solution","authors":"G. Curran, D.J. Engelken","doi":"10.1109/PLANS.1990.66226","DOIUrl":"https://doi.org/10.1109/PLANS.1990.66226","url":null,"abstract":"The Honeywell H700-3A ring laser gyro missile guidance set (AN/DJW-51) provides navigation, guidance, autopilot, weapons dispensing, and communications functions for the US Army TACMS missile in a low-initial-cost and low-life-cycle-cost package. It is primarily the use of low-cost inertial sensors which make the use of a ring laser gyro navigation system feasible in the tactical missile market. The H700-3A ring laser gyro missile guidance set has proven to be a low-cost, high-accuracy guidance and navigation system for the deep-strike Army missile weapons system. This has been borne out by a highly successful test program of 26 missile flights. The components of the missile guidance set are described in detail.<<ETX>>","PeriodicalId":156436,"journal":{"name":"IEEE Symposium on Position Location and Navigation. A Decade of Excellence in the Navigation Sciences","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114986786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Ananda, H. Bernstein, K. Cunningham, W. Feess, E.G. Stroud
{"title":"Global Positioning System (GPS) autonomous navigation","authors":"M. Ananda, H. Bernstein, K. Cunningham, W. Feess, E.G. Stroud","doi":"10.1109/PLANS.1990.66220","DOIUrl":"https://doi.org/10.1109/PLANS.1990.66220","url":null,"abstract":"A system description, a discussion of design issues, and performance results obtained from the Aerospace Corporation simulation of the GPS autonomous navigation system (ANS) concept are given. Analysis methods, physical models, and pertinent equations are presented. Measurement data are realistically simulated and include the effects of all known environmental and hardware phenomena affecting performance. Performance under nominal and anomalous conditions (satellite failures) and in nuclear environments is described. Unobservable errors which degrade performance are discussed. Preliminary studies show that the full constellation system is measurement rich. A simple scheme such as rejecting low signal-to-noise ratio or high delay measurements will probably be a satisfactory design response to distortion due to scintillation in the enhanced environment.<<ETX>>","PeriodicalId":156436,"journal":{"name":"IEEE Symposium on Position Location and Navigation. A Decade of Excellence in the Navigation Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124680311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Determination of precise position of a moving vehicle with GPS","authors":"C. Goad","doi":"10.1109/PLANS.1990.66187","DOIUrl":"https://doi.org/10.1109/PLANS.1990.66187","url":null,"abstract":"Global Positioning System (GPS) phase data were collected from a receiver moving on a vehicle whose position and velocity were being monitored by another precise tracking system. Centimeter-level agreement was found between the two systems. Except for initial positioning or alignment biases of 2-3 cm, root-mean-square (RMS) values were often less than 1 cm. It is thus concluded that precise GPS measurements of carrier phase can be used to determine relative position even while in motion.<<ETX>>","PeriodicalId":156436,"journal":{"name":"IEEE Symposium on Position Location and Navigation. A Decade of Excellence in the Navigation Sciences","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121727455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Application of electronic chart systems in the prevention of ship's groundings","authors":"H. Lanziner, D. Michelson","doi":"10.1109/PLANS.1990.66157","DOIUrl":"https://doi.org/10.1109/PLANS.1990.66157","url":null,"abstract":"It is noted that despite glowing recommendations from users, the market for electronic charts has not grown at the rate that many had expected. Some of the possible reasons for this are considered, and recommendations for corrective action are presented. One reason may be that shipping is a conservative and very cost-conscious industry; because ships have sailed without electronic charts in the past, it is difficult to convince owners that it is necessary to rush out and have one installed. The situation is compounded by the lack of international standards for electronic chart display (ECDIS) systems and, indeed, by the lack of international regulations requiring the use of ECDIS systems on board ship. However, it is generally recognized that electronic charts provide the only reasonable method of presenting precise position information to masters or pilots during critical maneuvering in restricted waters such as harbors and harbor approaches. As hardware becomes more sophisticated and capable, as experience is accumulated, and as precise positioning systems (e.g. GPS and RANAV) become widely available during the 1990s, it is expected that the market for electronic charts will grow tremendously.<<ETX>>","PeriodicalId":156436,"journal":{"name":"IEEE Symposium on Position Location and Navigation. A Decade of Excellence in the Navigation Sciences","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124280152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A GPS receiver with built-in precision pointing capability","authors":"R. Brown, P. Ward","doi":"10.1109/PLANS.1990.66161","DOIUrl":"https://doi.org/10.1109/PLANS.1990.66161","url":null,"abstract":"A Global Positioning System (GPS) pointing experiment using a single five-channel AN/PSN-9 GPS receiver developed for military manpack/vehicular applications is described. The AN/PSN-9 basically a dual-port per channel design, which results in minimum hardware and highest pointing accuracy by using common hardware to perform the GPS differential phase measurements from two GPS antennas. Procedures to solve for the phase double-difference ambiguities are described, and results are presented which demonstrate pointing solution convergence in less than 10 s with arbitrary movement of the antenna beam. Pointing estimates based on filtered, unambiguous phase double-difference observables from AN/PSN-9 GPS pointing unit indicate the potential of achieving 0.5-mr (0.3 degrees ) AZ pointing accuracy with only 1-m antenna baseline separation.<<ETX>>","PeriodicalId":156436,"journal":{"name":"IEEE Symposium on Position Location and Navigation. A Decade of Excellence in the Navigation Sciences","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130253154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Terrain aided navigation: current status, techniques for flat terrain and reference data requirements","authors":"A. Henley","doi":"10.1109/PLANS.1990.66235","DOIUrl":"https://doi.org/10.1109/PLANS.1990.66235","url":null,"abstract":"It is pointed out that terrain referenced navigation (TRN) techniques are now well established as effective position-fixing systems suitable for use in manned and unmanned vehicles. The SPARTAN TRN technique, which has been selected for the UK Tornado GR4 update, provides accurate navigation with rapid initial capture without recourse to an initialization mode. An overview of the SPARTAN technique is provided, and techniques for improving navigation performance over very flat terrain are described. The benefits of the terrain characteristic matching techniques are outlined, and a summary of integrated navigation system performance is given. Terrain-aided systems require appropriate reference databases. The availability of the data and its suitability are discussed. The need for careful consideration of database quality and registration when terrain aided systems are being designed is indicated.<<ETX>>","PeriodicalId":156436,"journal":{"name":"IEEE Symposium on Position Location and Navigation. A Decade of Excellence in the Navigation Sciences","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128005776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Heli/SITAN: a terrain referenced navigation algorithm for helicopters","authors":"J. Hollowell","doi":"10.1109/PLANS.1990.66236","DOIUrl":"https://doi.org/10.1109/PLANS.1990.66236","url":null,"abstract":"Heli/SITAN is a terrain referenced navigation algorithm that utilizes radar altimeter ground clearance measurements in combination with a conventional navigation system and a stored digital terrain elevation map to estimate a helicopter's position accurately. Multiple model adaptive estimation techniques are used, and a bank of single-state Kalman filters is used to ensure that reliable position estimates are obtained even in the face of large initial position errors. A real-time implementation of the algorithm was tested aboard a US Army UH-1 helicopter equipped with a Singer-Kearfott Doppler velocity sensor and a Litton LR-80 strapdown attitude and heading reference system (AHRS). The median radial error of the position fixes provided in real time by this implementation was less than 50 m for a variety of mission profiles. Although Heli/SITAN was demonstrated on a helicopter equipped with a Doppler aided AHRS, the extension to other types of aircraft and navigation systems is straightforward.<<ETX>>","PeriodicalId":156436,"journal":{"name":"IEEE Symposium on Position Location and Navigation. A Decade of Excellence in the Navigation Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130600770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}