Environmental Application of Remote Sensing: CE 6900 Tennessee Technological University Department of Civil and Environmental Engineering Course Instructor:

Environmental Application of Remote Sensing: CE 6900

Tennessee Technological UniversityDepartment of Civil and Environmental Engineering

Course Instructor: Dr . Faisal Hossain (Associate Prof.)

SOIL MOISTURE SATELLITES

By: Abebe Gebregiorgis

Outlines• Soil Moisture Active and Passive Satellite (SMAP) – NASA

– Introduction– Mission Imperative Overview– Scientific Objectives– Scientific Overview– Application Overview– Current status

• Soil Moisture and Ocean Satellite (SMOS) – ESA– Mission Imperative Overview and Scientific Objectives– Scientific Overview– Application Overview– Current status

• Summary

Soil Moisture Active Passive (SMAP) Satellite

Introduction

• SMAP - both active and passive sensors• L-band radiometer – (passive sensor )• L-band radar – (active sensor)

• Designed to provide – Global Soil moisture– Freeze/thaw

Mission• to provide global measurements of

soil moisture and freeze/thaw state via L-band radar and radiometry so as to

– Improve estimates of land surface evaporation, –Have good understanding of land-

atmosphere water and energy exchange

Specific objectives• Understand processes that link the terrestrial

water, energy and carbon cycles • Estimate global water and energy fluxes at the

land surface • Enhance weather and climate forecast skill • Develop improved flood prediction and drought

monitoring capabilities

Scientific OverviewArtistic rendition of the SMAP spacecraft

Scientific overview …• Orbit– Orbit Altitude: 670 km

(450 to 700 km)– Inclination: 98 degrees,

sun-synchronous – Local Time of Ascending

Node: 6 pm – SMAP will make

measurements from a 6am/6pm sun-synchronous polar orbit

Scientific overview …

• Configuration: Conically-scanning reflector – Diameter: 6 meters – Shared by both radar

and radiometer

Scientific overview …

• Configuration: – 1000 km wide swath – Scanning system: Along track scanning ???

SMAP Satellite’s swath path 1shows the initial path of the satellite

SMAP Satellite’s swath path 2shows the swath path illustrate the scanning pattern

of the antenna

SMAP Satellite’s swath path 3shows the swath path with more extensive

coverage

SMAP measurement geometry

Data Products

• Schematic representation of passive (left) and active (right) microwave interaction with soil and vegetation

Scientific overview …

• Configuration:

–Resolution: • 40 km radiometer • 1-3 km SAR (Synthetic Aperture Radar)• 10 km – combined product

–Rotation rate: 14.6 RPM–Beam efficiency: 90%

Data Products

• Soil Moisture– L-Band Radiometer (1.41 GHz)• Resolution = 40 km

– L-Band Radar (1.26 GHz)• Resolution = 10 km

• Freeze/Thaw– L-Band Radar (1.26 GHz)– Resolution 3 km

Data Products

• Sampling duration– 6 am/ 6 pm

• Revisit duration– Global = 3 days– Boreal = 2 days

• Mission life– Minimum = 3 years

Application Overview• Hydrological Hazards Applications: – Drought and Flood

• Ecosystem Services Applications– Agricultural Productivity

• Weather Forecast Applications• Climate Prediction Applications• Human Health Applications

SMAP launch is currently targeted for 2014

Status

SOIL MOISTURE AND OCEAN SALINITY (SMOS) SATELLITE

Introduction• European Space Agency (ESA)

• The SMOS mission is a direct response to the current lack of global observations of soil moisture and ocean salinity

• It objectives are to: – globally monitor surface soil moisture over land surfaces, – globally monitor surface salinity over the oceans, and – Improve the characterization of ice and snow covered

surfaces.

Scientific overview• altitude of 755 km• view an area of almost 3000 km in diameter.

SMOS Click here

• Launch: 2009• Duration: Minimum 3 years• Instrument: Microwave Imaging Radiometer• Instrument concept: Passive microwave• Frequency: L-band (21 cm -1.4 GHz)• Number of receivers: 69• Spatial resolution: 35 km• Temporal resolution: 3 days revisit at Equator• Swath: 3000 km

Scientific application• Soil moisture • Ocean salinity

Current Status

SMAP & SMOS• Do they have overlapping mission?• May new science opportunities arise if data from

SMAP and SMOS mission are combined ?

Facts:• SMOS will explore a potential technology but will provide

only a 35 km resolution• SMAP will explore a potential technology and different

instrument design and will provide a 10 km resolution• SMOS - ocean salinity, whereas SMAP -freeze/thaw

100 km 10 km 1 km

Day

Week

Month

SMOS SMAP Radar-Radiometer

ClimateClimate ApplicationsApplications

Weather ApplicationsWeather Applications

CarbonCarbon CycleCycle ApplicationsApplications

Resolved Spatial Scales

Res

olve

d T

emp

oral

Sca

les

Radio

met

er

RadarEvolution of L-Band Sensing

Evolution of SMOS & SMAP

Thank You

This material is extracted and compiled from • http://smap.jpl.nasa.gov/• http://www.esa.int/esaLP