fmcw radar overview

US Army Corpsof Engineers Engineer Research & Development Center

FMCW Radar Overview

Review of FMCW technologyReview of FMCW technology

CRREL FMCW Radar ApplicationsCRREL FMCW Radar Applications

FMCW Radar Plans for CLPX?FMCW Radar Plans for CLPX?


FMCW Radar Source Signal

Frequency varies linearly with time

Snow Surface


Transit time (2R/c)Beat Frequency

ReferenceTarget

FMCW Radar Parameters


Time (ms)0 16 32 48 64

Am

plit

ud

e

-2

-1

0

1

2

Frequency (kHz)200 400 600 800 1000

Mag

nit

ud

e

0.0

0.2

0.4

0.6

0.8

1.0

FMCW Radar Output

Mixer Output FFT of Mixer Output


Why FMCW Radar?

Inexpensive and easy to operateInexpensive and easy to operate

Field portable and robustField portable and robust

Wide bandwidth capabilityWide bandwidth capability


CRREL FMCW Radar

Ku-Band FMCW Radar

25 dB horn25 dB hornHP microwave sourceHP microwave source

LabVIEW data acquisitionLabVIEW data acquisition


Range (m)

2.50 2.75 3.00 3.25 3.50 3.75

Mag

nit

ud

e (

arb

un

its

)

0

25

50

75

100

125

150

8.0 - 12.0 GHz 9.5 - 10.5 GHz

FMCW Radar Bandwidth Diversity

Resolution ~ 1/Bandwidth


Snow Depth Measurements

Ka- and X-band FMCW Radar Experimental Results

Distance (m)

0 20 40 60 80 100

Sn

ow

De

pth

(c

m)

0.0

0.2

0.4

0.6

0.8

Manual Probe X-Band FMCW Radar


Polar Firn Stratigraphy

FMCW Radar in Greenland

Summer 1998

Summer 1997

Summer 1996

Summer 1995

Summer 1994

Summer 1993

0 20 40 60 80 100Distance (m)

0.0

0.5

1.0

1.5

2.0

2.5D

ep

th (

m)

Snow Pit Data(Hoar Location)

Hoar Stratigraphy


Ice Channel Detection with Microwave FMCW Radar

ExcavatedIce Channel

Ice Channels

Experiment Setup and Results

Corner Reflectors

Snow Surface

2- 6 GHz FMCW Radar


Radar Detection of Landmines

Snow Covered Test Site Anti-tank Mines in Frozen Ground


Radar Backscatter Measurements


Electromagnetic Signature of Snow, Ice and Frozen Ground

CRREL Test FacilityOptical and MMW Radar Data


FMCW Radar for CLPX?

Polarimetric backscatter (L,C,X,Ku)Polarimetric backscatter (L,C,X,Ku)

Multiband radar properties of snow Multiband radar properties of snow (C,X,Ku,Ka,V,W) (C,X,Ku,Ka,V,W)

Subsurface melt detectionSubsurface melt detection


Mobile Backscatter Measurements

B

CAA

B

C


Multiband Radar Properties of Snow Cover

X-band (8-12 GHz)

Ka-band (26.5-40 GHz)

C-band (3.9-5.9 GHz)


Subsurface Melt in Snow

Time series measurements.Time series measurements.

fmcw radar overview

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