ALOS Data Users Handbook

More documents

Recommendations

Info

Section 7 Overview of Processing Algorithms⎛f ( t)= cos 2π⎜ F⎝τ τ− ≤ t ≤2 2ck ⎞+ t ⎟ ⋅t2 ⎠Equation 7.3-1Where,F c denotes the transmission carrier frequency,k denotes the chirp rate (a function of temperature) andτ denotes the transmission pulse width.For the above transmission signal, the received signal f R (t) is represented approximately by the followingequation.⎧k2⎫f R ( t)= exp 2πj⎨ ( t −Tr) − FcTr+ Fd( t)⋅( t −Tr) ⎬⎩2⎭Equation 7.3-2τ τ− + Tr≤ t ≤ + Tr2 2Where, F d (t) denotes the Doppler frequency, T r denotes the time necessary for electromagnetic wavepropagation.In the term for the phase in the above equation, the first term denotes the transmission chirp wave componentand the second term denotes the phase delay created by the time necessary to make a round trip between thesatellite and the target. Since the distance between the satellite and the target varies for every pulse repeatcycle, the phase in the second term varies and this becomes the Doppler component in the azimuth direction.The third term denotes the phase shift component created because the transmitting position and the receivingposition of the electromagnetic wave differ since the satellite is moving when it transmits and receives theelectromagnetic wave.This received signal becomes the input signal of the range compression. The correlation operation in therange direction is conducted in the frequency domain by FFT. Thus, the received signal F(f) in the frequencydomain is represented as follows.F( f ) = ∫ f R ( t)⋅exp(−2πjft)dtEquation 7.3-3Where reference function of this is shown as Equation 7.3-4 and the complex conjugate in the frequencydomain is represented by G(f)*, the range-compressed signal h(t) is obtained by conducting a reverse FFT onthe product of F(f) and G(f)* and represented as follows.h( t)= ∫ F(f ) ⋅G*( f ) ⋅exp( 2πjft)dtEquation 7.3-47-28
ALOS Data Users HandbookTransmission OutputTimeTransmission FrequencyCentral FrequencyWithin the Chirp BandPulse WidthTimeOutput LevelWithin the Chirp BandCentral FrequencyFrequencyFigure 7.3-4 Schematic Diagram of the Transmission PulseWhen there is an irregularly strong line spectrum distributing at a specific frequency, it is expected that theline spectrum will degrade the image as noise while reproducing the image. The necessary noise reduction isconducted on the SAR data converted into the frequency domain.When there is a line spectrum having a power exceeding a threshold value in the data in the frequency7-29
Page 3:
Meantime, global environmental prob
Page 6 and 7:
Table Of Contents6.1.2 Scene Defini
Page 8 and 9:
Table Of ContentsTable 5.2-1 ALOS O
Page 10 and 11:
Table Of ContentsFigure 3.4-12 Layo
Page 13:
ALOS Data Users HandbookSection 1 I
Page 16 and 17:
Section 2 ALOS Missionphotovoltaic-
Page 18 and 19:
Section 2 ALOS Missiontrial fabrica
Page 20 and 21:
Section 3 Outline of ALOS Satellite
Page 22 and 23:
Page 24 and 25:
Page 26 and 27:
Page 28 and 29:
Page 30 and 31:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Page 38 and 39:
Page 40 and 41:
Page 42 and 43:
Page 44 and 45:
Page 46 and 47:
Page 48 and 49:
Page 50 and 51:
Page 52 and 53:
Page 54 and 55:
Page 56 and 57:
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Section 4 Overview of ALOS Mission
Page 72 and 73:
Section 4 Overview of ALOS Mission
Page 75 and 76:
ALOS Data Users HandbookSection 5 A
Page 77 and 78:
ALOS Data Users Handbook5.3 Operati
Page 79 and 80: ALOS Data Users HandbookBecause CH1
Page 81 and 82: ALOS Data Users Handbook240Mbps rec
Page 83 and 84: ALOS Data Users HandbookDRTS.As a c
Page 85 and 86: ALOS Data Users HandbookIn this met
Page 87: ALOS Data Users HandbookTable 5.8-1
Page 90 and 91: Section 6 ALOS Data Productsnumber
Page 92 and 93: Section 6 ALOS Data Products6.1.3 P
Page 94 and 95: Section 6 ALOS Data ProductsFigure
Page 96 and 97: Section 6 ALOS Data ProductsTable 6
Page 102 and 103: Section 6 ALOS Data ProductsTable 6
Page 104 and 105: Section 7 Overview of Processing Al
Page 137 and 138: ALOS Data Users HandbookSection 8 D
Page 139 and 140: ALOS Data Users Handbook8.5 Outline
Page 141 and 142: ALOS Data Users HandbookALOS Centra
Page 143 and 144: ALOS Data Users HandbookWith respec
Page 145 and 146: ALOS Data Users Handbook8.7 AUIG8.7
Page 147 and 148: ALOS Data Users HandbookFigure 8.7-
Page 149 and 150: ALOS Data Users Handbook8.7.3 NOTES
Page 151: APPENDIXALOS Data Users Handbook
Page 154 and 155: Appendix 1 Acronyms and Abbreviatio
Page 157 and 158: ALOS Data Users HandbookAppendix 2
show all

ALOS Data Users Handbook

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?