1 / 18

Peter Webley KCL

Experiences using a local AVHRR receiving station to assist monitoring of Central American volcanoes. Peter Webley KCL. AVHRR Real time Volcano Monitoring Project. Objectives Improve geological and geotechnical hazard avoidance capacity

sulwyn
Download Presentation

Peter Webley KCL

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Experiences using a local AVHRR receiving station to assist monitoring of Central American volcanoes Peter Webley KCL

  2. AVHRR Real time Volcano Monitoring Project • Objectives • Improve geological and geotechnical hazard avoidance capacity • Improve capacity for low cost, rapid hazard, risk and vulnerability assessment • Development systems for maintaining and improving national geoscience information • Assess the capability of remote sensing for enhancing operational volcano monitoring • Incorporates both geophysical and social science components

  3. AVHRR Real time Volcano Monitoring Project • Accomplishments • Installation of the AVHRR receiving station • Provided the software to allow the INETER staff to capture the data in real time • Designed and installed automated capture and analysis system • Carried out extensive case studies into the application of AVHRR to monitor and detect thermal volcanic activity • Designed analysis system to monitor volcanoes in Nicaragua, Guatemala, El Salvador and Costa Rica • Development of web based interface for data download and thermal monitoring • Multi-National Workshop in Nicaragua during March 2004 • Developments • Thermal fingerprint to detect eruption • E-mail alert system • Assessment of operational use of system • Ash cloud monitoring system

  4. Co-operating Countries and Partners • Countries • Nicaragua, Guatemala, Costa Rica and El Salvador • UK, USA and Japan • Partners • BURS – Bradford University Remote Sensing • KCL – Kings College London • INETER - Instituto Nicaraguense de Estudios Territoriales • CONRED - Comisión Nacional para Reducción de Desastres • INSIVUMEH – Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia. • SNET - Servicio Nacional de Estudios Territoriales • OVSICORI - Observatorio Vulcanológico y Sismológico de Costa Rica • MTU – Michigan Technology University • University of Tokyo

  5. AVHRR Receiving Station and Data • Swath area : 2000 km * 2000km • 6 - 8 satellite passes per day • Data • 5 Spectral Channels • Measuring Reflectance and Temperature • At 1.1 km resolution at nadir • Analysis • Use T3– T4 to look at volcanic activity • Determine radiance for the hotspot pixels • Use T4– T5 for ash cloud test • Provide time series of important data

  6. Planning orbits

  7. AVHRR Capture Software • Data Capture • Data calibration • Data converted to universal format • Processing fully automated

  8. Capture System : Automatic • NOAA Scheduler • Carries out orbit planning, data capture and data calibration • Conversion to universal format automated

  9. Computing/Data Storage • Computing • Data Capturing • Data Analysis • Software • BURS • ENVI/IDL • Data files • RAW – 10 – 40 MB • ENVI BIL – 90 – 180 MB • Data Storage • Per day: 400 – 500 MB • CD backup • Copied each week • Storage within INETER • Development to DVD storage • Analysis outputs • Stored on PC • Displayed on website

  10. Analysis System : Stage 1 • Uses IDL/ENVI • Automatically compiles and runs code if pass within past 30 minutes • If no pass, then will close and re-load in 30 minutes • Loads AVHRR scene into ENVI and extracts the following data • Channels 1 to 5, Latitude and Longitude • Satellite Azimuth, Satellite Elevation, Sun Azimuth and Sun Elevation • 8 volcanoes in Nicaragua, 8 in Guatemala, 4 in Costa Rica and 4 in El Salvador • Assigns a pixel corresponding to the volcano summit • For each volcano, program carries out the following analyses • Find the Max Temp 3 – 4 close to the summit pixel • Determines Thresholds to detect ‘hot/anomalous’ pixels • Determines Radiance anomalies • Carries out Cloud Analysis of region surrounding the volcano

  11. Analysis System : Stage 2 • Finds the Maximum Temp 3 – 4 value in a 7 by 7 grid from summit pixel • Determines this is be an anomalous pixel and creates 7 by 7 grid around hotspot pixel • Determines the mean and standard deviation of this new array • Analyses to determine which pixels are anomalous. If none, then no radiance calculations • Uses these anomalous pixels in Radiance calculations

  12. Analysis System : Stage 3 • Calculates the Radiance for Channels 3, 4 and 5 from equation: λ = wavelength (m) T is temperature (K) L is Spectral Radiance (W/m2/sr/μm) h is Planck’s Constant (6.6*10-34 Js) k is Boltzmann’s constant (1.38*10-23 J/K) c is the speed of light (3*108 m/s) • Calculates 3 Radiance anomalies for those ‘hot’ pixels • Σ (Equivalent anomaly) • Radiance from Channel 3 – Radiance from Channel 4 equivalent to Channel 3 (T3, λ4) • Σ (Simulated anomaly) • Radiance from Channel 3 – Radiance from Channel 3 simulated • Simulated temperature from linear relationship between Channel 3 and 4 • Σ (Background anomaly) • Radiance from Channel 3 – Radiance from Channel 3 background • Background temperature from edge pixels of 7*7 grid

  13. Analysis System : Stage 4 • Determines fully georeferenced images for all 24 volcanoes in Central America • Creates text file outputs • Including Channels 1 to 5, Channels 3 – 4, 4 – 5 at volcano summit and hotspot • Latitude and Longitude at volcano summit and hotspot • Number of saturated pixels • Ash cloud pixels • Radiance anomalies • Updates time series figures for each volcano • Past week • Past month • Last 6 months (rolling) • Max per day • Creates ASCII gridded data centred on each volcano • Creates ENVI image files so user can analyse the data themselves • Creates ARCVIEW raster and shape files

  14. Outputs from Analysis (1) • Text file based outputs for each volcano • Channels 1 to 5 at Summit and hotspot • Channels 3 – 4 and 4 – 5 at summit and hotspot • Ash based and Saturated based pixels • Three Radiance anomalies • Distance between summit and hotspot • CI and Cloud value for summit pixel Cloud index + Summit value Radiance anomalies Date and time of image Channels 3, 4 and 5 at hotspot

  15. Outputs from Analysis (2) • Fully georeferenced images for each country and volcano • Processed data in real-time for own personal analysis • Gridded text files of AVHRR data for each volcano • Time series plots of text data.

  16. Data Availability • Real-time data accessible from website • Fully georeferenced imagery • Time series of Radiance anomalies • Gridded data around each volcano • Image files to allow users to carry own analysis. • Access to data by web site for all volcanoes by end of Sept 2004 • Data for Research • Access provided so user can order past data for research purposes. • Data available from March 2003 until present • Process for ordering and sending data being developed • Software required • BURS. Will be supplied to interested parties • ENVI. To analyse ‘img’ files. (www.rsi.com)

  17. Overview of Demonstration • Data planning • Data capture • Data calibration • Conversion of data to ENVI format • Automation of data capturing • Overview of analysis system

  18. Overview of Practical • Fuego eruption in January 2004 • Analysis of data for thermal activity • Use of ENVI • Data for 27th December 2003, 6th, 9th and 12th January 2004 • Outputting data to images and ASCII format • Demo of analysis system for images for 8th and 9th January • Time series of Thermal activity

More Related