Presentation Summary How Beacons are Located Using Low Earth Orbit (LEO) Satellites Requires Highly accurate Orbit information and Very Stable Beacon Oscillator.

Slides:

Advertisements

Similar presentations

SAR-DF 517 Search and Rescue 4-Band Precision Direction Finder

Advertisements

Satellites Smaller bodies orbiting larger ones. How big are satellites? ► The moon is a satellite of earth ► The earth is a satellite of the sun ► A satellite.

More Satellite Orbits Introduction to Space Systems and Spacecraft Design Space Systems Design.

Understand basic orbital mechanics and how orbits work Understand the different types of orbits used for different purposes Understand basic principles.

Folie 1 Performance Investigation on the High-Resolution Wide-Swath SAR System Operating in Stripmap Quad-Pol and Ultra-Wide ScanSAR Mode DLR - Institut.

COSPAS-SARSAT SPACE SEGMENT SATELLITE AIDED SEARCH AND RESCUE JANUARY 2009.

SARSAT. COSPAS-SARSAT CospasCOsmicheskaya Systyema Poiska Aariynyich Sudov which translates loosely into “Space System for the Search of Vessels in Distress”

Unit 2 GEOSTATIONARY ORBIT & SPACE SEGMENT

Communications - Access Schemes 1 Introduction to Space Systems and Spacecraft Design Space Systems Design.

Council for Technical Education & Vocational Training Rapti Engineering College Ghorahi, Dang Presentation on Satellite Communication Presented by Shailendra.

A beginner’s guide to amateur radio satellites

SEARCH AND RESCUE SATELLITE AIDED TRACKING (SARSAT)

Lecture 11: Satellite Communcation Anders Västberg Slides are a selection from the slides from chapter 9 from:

Comparing to CloudSat Cloud Profiles TutorialTutorial National Aeronautics and Space Administration

United Nations SPOC Meeting Miami, February 19-23, 2008 Local User Terminals Manuel Valenzuela.

Refinement of maritime users needs, Brussels December 18, 2002 The Galileo support to the Search and Rescue Programme (SAR/Galileo)

Climate and Global Change Notes 6-1 Satellite Fundamentals Types of Orbit Lower Earth Orbits (LEO) Polar Orbits Medium Earth Orbits (MEO) Highly Elliptical.

Ch2 Sec3 Maps and Computers.

2.4 GHz CubeSat Communications System Robert Bui Communications Subsystem Lead.

GPS. What is the Global Positioning System (GPS)? a satellite-based navigation system made up of a network of 24 satellites. a satellite-based navigation.

COMT 3911 Satellite Basics COMT 391 Wireless. COMT 3912 Satellite Components Satellite Subsystems –Telemetry, Tracking, and Control –Electrical Power.

GPS(Global Positioning System) -An Introduction. What is the GPS? Orbiting navigational satellites Transmit position and time data Handheld receivers.

ARL Applied Research Laboratories The University of Texas at Austin ARL Applied Research Laboratories The University of Texas at Austin Ionospheric Tomography.

10. Satellite Communication & Radar Sensors

406ELT General presentation by Lloyd Klee. Page 2 Specification documents  Early 70’s: first regulation (TSO-C91)  1983 : RTCA.

Channels of Communication SL – Option F.4. Ways of Communicating Wire Pairs –This is the cheapest form of cable, they are 2 insulated wires that are run.

U.S. RCC-SARSAT CONFERENCE 15 – 17 February 2011 National Data Distribution.

Chapter 8 ELT Emergency Locator Transmitter. ELT History In 1972, a law was passed requiring aircraft to carry a radio beacon for search and rescue. This.

Emergency Position Indicating Radio Beacon

Satellite Communications

Alert Message Formats for SAR Points of Contact (SPOCs) - Overview and Interpretation - Tom Griffin, USMCC Senior Systems Analyst U.N./USA Training Course.

Mastering Astronomy.

Lecture 4: Global Positioning System (GPS)

Channels of Communication HL – Option F.4 Mr. Jean.

Channels of Communication HL – Option F.4 Mr. Jean April 22 nd, 2014.

Minnesota Wing Air Branch Director Course

From you host … Dr. H. Introduction Communications design requires us to think about the following issues: Communications design requires us to think.

SATELLITE ORBITS The monitoring capabilities of the sensor are, to a large extent, governed by the parameters of the satellite orbit. Different types of.

Global Positioning System Or, Where the heck am I ???

Introduction to the Global Positioning System Introduction to the Global Positioning System.

SPM Users Basic Training August 2010 Lecture VIII – AC Imaging Modes: ACAFM and MAC Imaging methods using oscillating cantilevers.

Orbits and Sensors Multispectral Sensors. Satellite Orbits Orbital parameters can be tuned to produce particular, useful orbits Geostationary Sun synchronous.

Agenda Item: 9.1 Title: Protection of the systems operating in the mobile-satellite service in the band MHz.

Bitwali.com 1 WIRELESS COMMUNICATION LEC bitwali.com 2 TYPES OF SATELLITES Satellite Orbits  GEO  LEO  MEO  Molniya Orbit Frequency Bands.

Search and Rescue Satellite-Aided Tracking System

Look Angle Determination

Chapter 2 - Mapping Our World

Communications Design Review

Satellite Communications

Lutetia Flyby Rosetta Radio Science Investigations RSI

GEOGRAPHIC INFORMATION SYSTEMS & RS INTERVIEW QUESTIONS ANSWERS

Satellite Communications

U.S. RCC-SARSAT CONFERENCE 23 – 25 February 2010

DIODE On-Board Orbit Determination function, providing :

How Things Work: Global Positioning System

SC/ UNIT- 5 CBS RADARSAT / KARTHIKA A, AP/ECE

Satellites orbits Lec /16/2018 Dr. Hassan Yousif.

The Inmarsat System in the GMDSS.

Off-Road Equipment Management TSM 262: Spring 2016

Orbital Mechanics Basic Orbits Include:

National Satellite Meteorological Centre

Technician Licensing Class

Communication System That Support the GMDSS

Making a good thematic map – Extracting or collecting geographic data

MEOSAR Beacon Modernization Discussion

By Stephen McBain (M????) Disclaimer: Not Claiming to be an expert

A. The signal strength of received signals

Presentation transcript:

Presentation Summary How Beacons are Located Using Low Earth Orbit (LEO) Satellites Requires Highly accurate Orbit information and Very Stable Beacon Oscillator Description Of Doppler Shift Ambiguity Resolution (side “A” or “B” Determination)

Satellite Types Two types of satellites: w LEO satellites in near-polar orbit w Geosynchronous earth orbiting (GEO) satellites (cannot provide Doppler info)

Determining Beacon Locations From LEO Doppler Data T1 T2 T3 850 km 3400 km Distress Beacon GEOMETRY FOR OVERHEAD PASS Frequency High Actual Low Time DOPPLER SHIFT CAUSES FREQUENCY TO APPEAR HIGHER THAN ACTUAL DOPPLER SHIFT CAUSES FREQUENCY TO APPEAR LOWER THAN ACTUAL TIME OF CLOSEST APPROACH (AND ACTUAL FREQUENCY)

Processor and On-Board Memory COSPAS-SARSAT Processor and On-Board Memory SAR Processor Extracts the beacon ID Measures the signal’s frequency Time tags the frequency measurement On-Board Memory Stores the processed data Continually transmits the stored data (typical hold time is several hours) 406 MHz Beacon SAR Processor LUT Ground Station Local User Terminal

Doppler Curve (Processed by LUT) Satellite S4, orbit 12587 1991 MAR 05 18:16:31.80 Doppler Curve (Processed by LUT) Max Elevation 60o 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Time (secs) Frequency (kHz)

Time of Closest Approach (TCA) Satellite S4, orbit 12587 1991 MAR 05 18:16:31.80 Time of Closest Approach (TCA) TCA Occurs at Zero Doppler Shift 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Time (secs) Frequency (kHz)

Typical Doppler Curves Doppler Frequency vs. Time -10 -8 -6 -4 -2 2 4 6 8 10 5 15 20 Time (minutes) Frequency (KHz) TCA Pass 1 (High Elevation) Pass 2 (Low Elevation)

First Location (A / B Ambiguity) Gnd Trk Pass 1 (time is measured along gnd trk) 1A 1B Longitude Latitude TCA

A / B Ambiguity Resolved Gnd Trk Pass 1 Gnd Trk Pass 2 1A 1B 2A 2B Longitude Latitude

Two Pass, Merged Location Gnd Trk Pass 1 Gnd Trk Pass 2 1B 2B Longitude Latitude Merged Location

Ground Track and Field of View T2 -T1 = 101 minutes D longitude – 25 Deg.

Resolving Location Ambiguity 1 LEGEND: ground tracks of successive spacecraft orbits 1A, 1B Real and Image solutions from pass 1 2A, 2B Real and Image solutions from pass 2 2 2B 1B 2A 1A Two Pass Solution for a Beacon Located in Brazil