Environmental Application of Remote Sensing: CE 6900 Tennessee Technological University Department 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 Overview Artistic 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 Satellites swath path 1 shows the initial path of the satellite

SMAP Satellites swath path 2 shows the swath path illustrate the scanning pattern of the antenna

SMAP Satellites swath path 3 shows 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 km10 km1 km Day Week Month SMOSSMAP Radar-Radiometer Climate Applications Weather Applications Carbon Cycle Applications Applications Resolved Spatial Scales Resolved Temporal Scales Radiometer Radar Evolution of L-Band Sensing Evolution of SMOS & SMAP

Thank You This material is extracted and compiled from