research overview
- Professor Axelrad's primary research focus is on methods and applications for positioning, navigation, and timing (PNT), including Global Navigation Satellite Systems (GNSS) or GPS and alternative PNT.
- Contact Info
Axelrad, Penina
Positions
- Endowed/Named Professor, College of Engineering and Applied Science
- Associate Dean, College of Engineering and Applied Science
- Distinguished Professor, Aerospace Engineering Sciences
Research Areas
Research
keywords
- Global Navigation Satellite Systems (GPS / GNSS) technology and applications, clocks, orbit estimation, Space Domain Awareness
Publications
selected publications
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book
- Global Positioning System: Theory and Applications. Ed. Axelrad, Penina. 1996
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chapter
- GPS Navigation Algorithms. 409-433. 1996
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conference proceeding
-
Evaluating an Ionosphere Sensing Capability on Suborbital Launch Vehicles.
3211-3226.
2025
- Autonomous spacecraft navigation in cislunar space using quantum gravity gradiometers 2025
-
Forward Looking Reflections on GNSS-R.
68-77.
2024
- Asteroid gravity field estimation using a gravity gradiometer 2024
- Characterizing a Chip Scale Atomic Clock in Low Earth Orbit 2024
-
Development of a Lunar Surface Navigation Pseudolite Testbed.
3612-3630.
2023
- Arc-Constrained Multi-Target Tracking with Real Radar Observations 2023
-
A Multi-Platform Clock Ensemble Testbed.
223-235.
2023
- Multi-CubeSat Formation Design for a High-Precision Timing and Ranging Experiment in LEO 2023
-
A Flexible Ephemeris Representation for GNSS and Alternative PNT Signal Sources Using B-Splines.
799-807.
2022
-
Improved Modeling of the Solar Radiation Pressure for the Sentinel-6 MF Spacecraft.
3618-3631.
2022
-
Estimation Architectures for Precise Time and Frequency Transfer in a LEO Constellation
2022
-
CHARACTERIZING CSAC PERFORMANCE IN A SIMULATED MISSION ENVIRONMENT.
Advances in the Astronautical Sciences.
19-36.
2022
-
Signal Generation in a Low-SWaP Atomic Clock Ensemble.
45-57.
2022
- Application of SoleiTool for Density Estimation using CubeSat GPS Data 2021
-
A Testbed for Low-SWaP Atomic Clock Ensemble Development.
287-300.
2021
-
CubeSat Cluster Deployment Track Initiation via a Radar Admissible Region Birth Model.
Journal of Guidance, Control, and Dynamics.
1927-1934.
2020
-
IMPROVED ORBIT DETERMINATION OF THE CYGNSS SATELLITES AND ITS APPLICATION TO GNSS-R OCEAN ALTIMETRY.
5847-5850.
2020
-
Improved Single-frequency Orbit Determination for the CYGNSS Spacecraft.
3875-3887.
2020
- CSAC Flight Experiment to Characterize On-Orbit Performance 2020
-
Improved Urban Navigation with Direct Positioning and Specular Matching.
787-800.
2020
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Estimation of Thermal and Stochastic Variations of Chip Scale Atomic Clocks for Navigation of a Lunar CubeSat.
Proceedings of the Annual Precise Time and Time Interval Systems and Applications Meeting, PTTI.
221-233.
2020
- Physics based Approach to Density Estimation and Prediction using Orbital Debris Tracking Data 2019
- Track Initiation for CubeSat Cluster Deployment Tracking 2019
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TOWARDS AN OCEAN ALTIMETRY PRODUCT USING CYGNSS.
8700-8702.
2019
- EXTRACTING CUBESAT RELATIVE MOTION USING IN SITU DEPLOYMENT IMAGERY. Advances in the Astronautical Sciences. 59-68. 2019
- IMPROVING ORBIT DETERMINATION OF CLUSTERED CUBESAT DEPLOYMENTS USING CAMERA-DERIVED OBSERVATIONS. Advances in the Astronautical Sciences. 191-200. 2019
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High Stability Reference Clock for Small Satellites.
Proceedings of the Annual Precise Time and Time Interval Systems and Applications Meeting, PTTI.
149-167.
2019
- LABEL ASSIGNMENTS IN CUBESAT CLUSTER DEPLOYMENT TRACKING. Advances in the Astronautical Sciences. 3959-3973. 2019
- Simulation of a high stability reference clock for small satellites with modeled GPS timing errors 2019
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Framework and Techniques for Cooperative Group Situational Awareness in Urban Environments.
253-270.
2018
- A Framework for Regional GNSS Situational Awareness. 2452-2466. 2018
- Investigation of CSAC Driven One-Way Ranging Performance for CubeSat Navigation 2018
- A COMPARISON OF WAVEFORM MODEL RE-TRACKING METHODS USING DATA FROM CYGNSS. 4289-4292. 2018
- Assessing the Altimetric Measurement from CYGNSS Data. 8292-8295. 2018
- A Framework for Regional GNSS Situational Awareness. 2452-2466. 2017
- Boundaries on Range-Range Constrained Admissible Regions for Optical Space Surveillance 2017
- Harnessing Orbital Debris to Sense the Space Environment 2017
- Cubesat Cluster Deployment Tracking with a CPHD Filter 2017
- Multipath Modeling and Validation for GPS Onboard the International Space Station 2017
- Utilizing novel non-traditional sensor tasking approaches to enhance the space situational awareness picture maintained by the Space Surveillance Network 2016
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Characterization of Specialized Geosynchronous Elements for Space Situational Awareness Applications
2016
- Validation of GNSS Multipath Model for Space Proximity Operations Using the Hubble Servicing Mission 4 Experiment. 3635-3643. 2016
- Fast and Reliable GNSS Attitude Estimation Using a Constrained Bayesian Ambiguity Resolution Technique (C-BART). 2809-2820. 2015
- Evaluation of the GNSS Multipath Environment in Space Proximity Operations: Experimental and Simulation Studies of Code Correlations in Hubble Servicing Mission 4. 863-871. 2015
- Analysis of Error Sources in Phase Rate Measurements in GPS Radio Occultation. 1478-1491. 2014
- Characterization of Expected Multipath Error for the NICER X-Ray Telescope Payload. 2448-2456. 2014
- COMPARISON OF MULTITARGET FILTERING METHODS AS APPLIED TO SPACE SITUATIONAL AWARENESS. Advances in the Astronautical Sciences. 959-976. 2013
- Turbulence Retrievals from Radio Occultations 2013
- Detection of Atmospheric Turbulence in GPS-RO Amplitude Spectra. 3380-3391. 2012
- A NEW NUMERICAL INTEGRATION TECHNIQUE IN ASTRODYNAMICS. Advances in the Astronautical Sciences. 1709-+. 2012
- MINIMUM L1 NORM ORBIT DETERMINATION USING A SEQUENTIAL PROCESSING ALGORITHM. Advances in the Astronautical Sciences. 1457-1473. 2012
- EARTH ORIENTATION PARAMETER CONSIDERATIONS FOR PRECISE SPACECRAFT OPERATIONS. Advances in the Astronautical Sciences. 1919-1931. 2011
- OVERVIEW OF SPACE APPLICATIONS OF GLOBAL NAVIGATION SATELLITE SYSTEMS. Advances in the Astronautical Sciences. 23-35. 2011
- GEO Satellite Positioning Using GPS Collective Detection. 2706-2716. 2010
- Performance Analysis of Collective Detection of Weak GPS Signals. 3041-3053. 2010
- ANALYSIS OF SPECIALIZED COORDINATE REPRESENTATION FOR DYNAMIC MODELING AND ORBIT ESTIMATION IN THE GEOSYNCHRONOUS REGIME. Advances in the Astronautical Sciences. 2075-+. 2010
- Enhancing GNSS Acquisition by Combining Signals from Multiple Channels and Satellites. 2617-2628. 2009
- Effects of orbital perturbations on the performance of a relative navigation filter for high Earth orbits. Advances in the Astronautical Sciences. 819-848. 2007
- A Modular GPS Remote Sensing Software Receiver for Small Platforms. 634-642. 2006
- Assessment of Digital Terrain Models for Multipath Prediction at Geodetic GNSS Installations. 2815-2823. 2006
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Measurement of backscattered GPS signals.
664-+.
2006
- Analysis of relative navigation in highly eccentric orbits. Advances in the Astronautical Sciences. 291-+. 2006
- Airborne GPS bistatic radar soil moisture measurements during SMEX02. 896-898. 2003
- Seasonal polarimetric measurements of soil moisture using tower-based GPS bistatic radar. 781-783. 2003
- Automated operational orbit determination for the ICESat mission. Advances in the Astronautical Sciences. 399-414. 2003
- Applications of drag-free technology to precision satellite navigation. Advances in the Astronautical Sciences. 1757-1768. 2001
- GPS-based remote sensing of ocean-surface wind speed from space. 2522-2524. 2001
- Student reflected GPS experiment (SuRGE). 1518-1520. 2001
- ICESat attitude algorithm for maintained reference groundtrack pointing. Advances in the Astronautical Sciences. 1115-1130. 1999
- Reducing selective availability effects on post-processed orbits for satellites with limited GPS telemetry. Advances in the Astronautical Sciences. 1477-1489. 1999
- Adaptive detection of code delay and multipath in a simplified GPS signal model. 569-581. 1997
- Initial demonstration of a point solution algorithm for orbit determination using the microGPS receiver. 377-386. 1997
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The student nitric oxide explorer.
Proceedings of SPIE.
121-132.
1996
- Application of the extended Kalman filter for relative navigation in an elliptical orbit. Advances in the Astronautical Sciences. 693-712. 1996
- Precision orbit determination for GFO and GFO-2. Advances in the Astronautical Sciences. 1331-1342. 1996
- A comparison of GPS-based attitude estimation techniques for spinning satellite. 1785-1796. 1995
- Relative motion in highly elliptical orbits. Advances in the Astronautical Sciences. 1359-1376. 1995
- AN INTEGRATED GPS ATTITUDE DETERMINATION SYSTEM FOR JAWSAT. 1251-1261. 1994
- THE USE OF GPS BUOYS TO CALIBRATE ALTIMETRIC SATELLITES. 221-230. 1994
- USE OF SIGNAL-TO-NOISE RATIO FOR MULTIPATH ERROR CORRECTION IN GPS DIFFERENTIAL PHASE MEASUREMENTS - METHODOLOGY AND EXPERIMENTAL RESULTS. 655-666. 1994
- DISTURBANCE LEARNING CONTROL FOR SMALL SATELLITES. 2882-2886. 1994
- ON-ORBIT GPS BASED ATTITUDE & ANTENNA BASELINE ESTIMATION. 441-450. 1994
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Evaluating an Ionosphere Sensing Capability on Suborbital Launch Vehicles.
3211-3226.
2025
-
journal article
-
A Lunar Surface Pseudolite Architecture for Regional Communication and Radionavigation.
IEEE Transactions on Aerospace and Electronic Systems.
5611-5634.
2025
-
Magnetospheric Cold Plasma Diagnostics Using High Altitude GNSS Signals.
Journal of Geophysical Research (JGR): Space Physics.
2025
-
Measuring river slope using spaceborne GNSS reflectometry: Methodology and first performance assessment.
Remote Sensing of Environment.
2025
-
Demonstration of a programmable optical lattice atom interferometer.
Physical Review Research.
2024
-
Sentinel-6 Michael Freilich precise orbit determination using PODRIX and TriG receiver measurements.
Journal of Geodesy.
2024
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Timescale Realization with Linked Platforms for AltPNT.
Navigation, Journal of the Institute of Navigation.
2024
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Overview of Space-Capable Global Navigation Satellite Systems Receivers: Heritage, Status and the Trend towards Miniaturization.
Sensors.
2023
-
Application of shaken lattice interferometry based sensors to space navigation.
Advances in Space Research.
4288-4301.
2023
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Extending the GPS IIIA antenna calibration for precise orbit determination of low Earth orbit satellites.
Journal of Geodesy.
2023
-
Modeling and Control of Ultracold Atoms Trapped in an Optical Lattice: An Example-driven Tutorial on Quantum Control.
IEEE Control Systems.
28-43.
2023
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A Flexible Ephemeris Representation for GNSS and Alternative PNT Signal Sources Using B-Splines.
Navigation, Journal of the Institute of Navigation.
2023
-
Improved GPS-Based Single-Frequency Orbit Determination for the CYGNSS Spacecraft Using GipsyX.
Navigation, Journal of the Institute of Navigation.
2023
-
Physics-Based Approach to Thermospheric Density Estimation Using CubeSat GPS Data.
Space Weather.
2023
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The Formation of a Chip Scale Atomic Clock Ensemble Using Software Defined Radios.
77-87.
2023
-
Design of a high-stability heterogeneous clock system for small satellites in LEO.
GPS Solutions.
2021
-
A low complexity smoothing algorithm for improved GPS point solutions on board LEO spacecraft.
Navigation, Journal of the Institute of Navigation.
185-198.
2021
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Chip Scale Atomic Clock-Driven One-Way Radiometric Tracking for Low-Earth-Orbit CubeSat Navigation.
Journal of Spacecraft and Rockets.
200-209.
2021
-
Identity Management of Clustered Satellites with a Generalized Labeled Multi-Bernoulli Filter.
Journal of Guidance, Control, and Dynamics.
2046-2057.
2020
-
CubeSat Cluster Deployment Track Initiation via a Radar Admissible Region Birth Model.
Journal of Guidance, Control, and Dynamics.
1927-1934.
2020
-
Improved GNSS-R Ocean Surface Altimetry With CYGNSS in the Seas of Indonesia.
IEEE Transactions on Geoscience and Remote Sensing.
6071-6087.
2020
-
Improved urban navigation with shadow matching and specular matching.
Navigation, Journal of the Institute of Navigation.
547-565.
2020
-
A Partially Orthogonal EnKF approach to atmospheric density estimation using orbital debris.
Advances in Space Research.
1965-1980.
2020
-
Advanced multipath modeling and validation for GPS onboard the International Space Station.
Navigation, Journal of the Institute of Navigation.
559-575.
2019
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Search-Detect-Track Sensor Allocation for Geosynchronous Space Objects.
IEEE Transactions on Aerospace and Electronic Systems.
2788-2808.
2018
-
Parallel initial orbit determination using angles-only observation pairs.
Celestial Mechanics and Dynamical Astronomy.
2018
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Global Ocean Altimetry With GNSS Reflections From TechDemoSat-1.
IEEE Transactions on Geoscience and Remote Sensing.
4088-4097.
2018
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Improved prediction of GPS satellite clock sub-daily variations based on daily repeat.
GPS Solutions.
2018
-
Sensor Allocation for Tracking Geosynchronous Space Objects.
Journal of Guidance, Control, and Dynamics.
149-163.
2018
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An Assessment of the Precision and Accuracy of Altimetry Retrievals for a Monterey Bay GNSS-R Experiment.
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing.
4660-4668.
2016
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Influence of ITRS/GCRS implementation for astrodynamics: Coordinate transformations.
Advances in Space Research.
850-866.
2016
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Bandlimited implicit Runge-Kutta integration for Astrodynamics.
Celestial Mechanics and Dynamical Astronomy.
143-168.
2014
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Satellite clock bias estimation for iGPS.
GPS Solutions.
381-389.
2013
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Observability of Relative Hybrid Elements, Given Space-Based Angles-Only Observations.
Journal of Guidance, Control, and Dynamics.
1681-1686.
2012
-
Along-Track Separation Uncertainty Modeling Given Space-Based Optical Observations.
Journal of Guidance, Control, and Dynamics.
732-739.
2012
-
Progress in turbulence detection via GNSS occultation data.
Atmospheric Measurement Techniques.
789-808.
2012
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Collective Detection and Direct Positioning Using Multiple GNSS Satellites.
Navigation, Journal of the Institute of Navigation.
305-321.
2011
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A Study of the Achievable Geosynchronous Angles-Only Orbit Estimation Accuracy.
Journal of the Astronautical Sciences.
275-290.
2011
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Specialized Coordinate Representation for Dynamic Modeling and Orbit Estimation of Geosynchronous Orbits.
Journal of Guidance, Control, and Dynamics.
1824-1836.
2010
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Bistatic Scattering of GPS Signals Off Arctic Sea Ice.
IEEE Transactions on Geoscience and Remote Sensing.
1548-1553.
2010
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Mounting-Angle Estimation for Personal Navigation Devices.
IEEE Transactions on Vehicular Technology.
1129-1138.
2010
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Mars Aerobraking Spacecraft State Estimation by Processing Inertial Measurement Unit Data.
Journal of Guidance, Control, and Dynamics.
1802-1813.
2008
-
Using GPS multipath to measure soil moisture fluctuations: initial results.
GPS Solutions.
173-177.
2008
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Modeling GPS phase multipath with SNR: Case study from the Salar de Uyuni, Boliva.
Journal of Geophysical Research (JGR): Solid Earth.
2008
-
A GNSS Code Multipath Model for Semi-Urban, Aircraft, and Ship Environments.
Navigation, Journal of the Institute of Navigation.
293-307.
2007
-
Relative semimajor axis uncertainty in high earth orbits.
Journal of Guidance, Control, and Dynamics.
1827-1831.
2007
-
Improving the precision of high-rate GPS.
Journal of Geophysical Research (JGR): Solid Earth.
2007
-
Analysis of relative navigation in high earth orbits.
Journal of the Astronautical Sciences.
23-52.
2007
-
Sea ice roughness from airborne LIDAR profiles.
IEEE Transactions on Geoscience and Remote Sensing.
3032-3037.
2006
-
Automated operational orbit determination for the Ice Cloud and Land Elevation Satellite mission.
Journal of Spacecraft and Rockets.
1048-1053.
2006
-
Formation design in eccentric orbits using linearized equations of relative motion.
Journal of Guidance, Control, and Dynamics.
146-160.
2006
-
Development of Multipath Error Budgets for JPALS Ground Station Receivers.
Navigation, Journal of the Institute of Navigation.
145-154.
2005
-
Modified sidereal filtering: Implications for high-rate GPS positioning - art. no. L22608.
Geophysical Research Letters.
2004
-
Initial results of land-reflected GPS bistatic radar measurements in SMEX02.
Remote Sensing of Environment.
507-520.
2004
-
Using GPS reflections for satellite remote sensing.
Acta Astronautica.
39-49.
2004
-
Retrieval of ocean surface wind speed and wind direction using reflected GPS signals.
Journal of Atmospheric and Oceanic Technology.
515-526.
2004
-
Application of successive interference cancellation to the GPS pseudolite near-far problem.
IEEE Transactions on Aerospace and Electronic Systems.
481-488.
2003
-
Orbit determination for the QuikSCAT spacecraft.
Journal of Spacecraft and Rockets.
852-858.
2002
-
Real-Time, Autonomous, Precise Orbit Determination Using GPS.
Navigation, Journal of the Institute of Navigation.
155-168.
2001
-
Carrier-Phase Multipath Corrections for GPS-based Satellite Attitude Determination.
Navigation, Journal of the Institute of Navigation.
76-88.
2001
-
GPS Receiver Architecture and Expected Performance for Autonomous Navigation in High Earth Orbits.
Navigation, Journal of the Institute of Navigation.
190-204.
2000
-
GPS signal scattering from sea surface: Wind speed retrieval using experimental data and theoretical model.
Remote Sensing of Environment.
162-174.
2000
-
Satellite attitude determination based on GPS signal-to-noise ratio.
Proceedings of the IEEE.
133-144.
1999
-
Ill-conditioned covariance matrices in the first-order two-step estimator.
Journal of Guidance, Control, and Dynamics.
754-760.
1998
-
Precision orbit determination for the GEOSAT Follow-On satellites.
Journal of Spacecraft and Rockets.
336-341.
1998
-
Adaptive SNR-based carrier phase multipath mitigation technique.
IEEE Transactions on Aerospace and Electronic Systems.
264-276.
1998
-
A Combined Filter for GPS-Based Attitude and Baseline Estimation.
Navigation, Journal of the Institute of Navigation.
195-213.
1997
-
Attitude estimation algorithms for spinning satellites using global positioning system phase data.
Journal of Guidance, Control, and Dynamics.
164-169.
1997
-
Spacecraft attitude estimation using the global positioning system: Methodology and results for RADCAL.
Journal of Guidance, Control, and Dynamics.
1201-1209.
1996
- The analysis of GPS attitude data from a slowly rotating, symmetrical gravity gradient satellite. Journal of the Astronautical Sciences. 515-539. 1996
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SNR-based multipath error correction for GPS differential phase.
IEEE Transactions on Aerospace and Electronic Systems.
650-660.
1996
-
CALIBRATION OF THE TOPEX ALTIMETER USING A GPS BUOY.
Journal of Geophysical Research (JGR): Oceans.
24517-24526.
1994
-
Wide Area Differential GPS.
Navigation, Journal of the Institute of Navigation.
123-145.
1991
-
Space Applications of GPS.
Navigation, Journal of the Institute of Navigation.
239-251.
1989
-
Closed Loop Navigation and Guidance for Gravity Probe B Orbit Insertion.
Navigation, Journal of the Institute of Navigation.
45-61.
1989
-
Autonomous GPS Integrity Monitoring Using the Pseudorange Residual.
Navigation, Journal of the Institute of Navigation.
255-274.
1988
-
A Lunar Surface Pseudolite Architecture for Regional Communication and Radionavigation.
IEEE Transactions on Aerospace and Electronic Systems.
5611-5634.
2025
editor of
Background
education and training
- Ph.D., Stanford University 1991
- M.S., Massachusetts Institute of Technology 1986
- B.S., Massachusetts Institute of Technology 1985
awards and honors
International Activities
geographic focus
- Argentina Country
- Australia Country
- France Country
- Israel Country
- Switzerland Country