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  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

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  alert system  Assessment of operational use of system  Ash cloud monitoring system

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

AVHRR Receiving Station and Data  Swath area : 2000 km * 2000km  satellite passes per day  Data  5 Spectral Channels  Measuring Reflectance and Temperature  At 1.1 km resolution at nadir  Analysis  Use T 3 – T 4 to look at volcanic activity  Determine radiance for the hotspot pixels  Use T 4 – T 5 for ash cloud test  Provide time series of important data BandWavelength (μm) Resolution (km) 1~ ~ a~ b~ ~ ~

Planning orbits

AVHRR Capture Software  Data Capture  Data calibration  Data converted to universal format  Processing fully automated

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

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

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

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

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/m 2 /sr/μm) h is Planck ’ s Constant (6.6* Js) k is Boltzmann ’ s constant (1.38* J/K) c is the speed of light (3*10 8 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 (T 3, λ 4 )  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

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

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 Date and time of image Radiance anomalies Channels 3, 4 and 5 at hotspot

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.

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. (

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

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