Transcript ДЛИННОВОЛНОВЫЙ ПЛАНЕТНЫЙ РАДАР ДПР-Ф

Subsurface radar sounding
of the Fobos ground
Long wave planetary radar
(LPR)
N.A.Armand, V.M.Smirnov, V.N.Marchuk, O.V.Yushkova,
Institute of Radioengineering and Electronics of RAS,
Moscow
V.V.Abramov, A.S.Bazhanov2
Special Design Bureau of IRE RUS,
Fryazino, Russia.
The experiment purpose,
expected results




Revealing of Phobos deep structure
Estimation of in-situ rock density of Phobos
ground
Research of a relief and roughness of Phobos
surface
Estimation of dielectric properties of a
ground on different depths along a line of the
spacecraft flight
THE PHYSICAL SCHEME OF EXPERIMENT
SC
Reflection of
subsurface
layers
Phobos
structure
Reflection of
surface
Layer 1
Layer 2
Layer 3
THE PHYSICAL SCHEME OF EXPERIMENT
Distance less then 1 km
Distance higher then 1 km
The scheme of carrying out
of survey sounding of a Phobos surface
by the radar LPR in a quasisynchronous orbit
Spacecraft orbit
Phobos
Mars
Phobos orbit
Height 50 – 100km. Mode 1: 1 measurement per 90 seconds,
8191 sub pulses in a code keying signal
The scheme of survey sounding of a Phobos surface
The scheme of survey sounding of a Phobos surface
The scheme of carrying out
of detailed sounding of a Phobos surface
by the radar LPR in a quasisynchronous orbit
H=50 km
Height 50 – 60 km. Mode 2: 2 measurement per second,
2047 sub pulses in a code keying signal.
It is planed 6 sessions in 10 min durations.
The scheme of detailed sounding of a Phobos
surface in a quasisynchronous orbit
The scheme of carrying out
of sounding of a Phobos surface
by the radar LPR at spacecraft landing
H=20 km
Mode 3
H=1 km
Mode 4
H=100 m
Phobos
surface
Height from 20 km to100 m.
Two sessions duration for 10 minutes, on 2 measurements per second.
Mode 3 - 255 sub pulses in a signal. Mode 4 - a monoimpulse.
The scheme of a Phobos surface
sounding at spacecraft landing
LPR outward appearance
Device LPR technical characteristics
Carrier frequency
150 MHz
Frequency range
15025 MHz
Spectrum band
43 MHz
Amplification factor
110 – 120 dB
Radio-frequency pulse duration
26,6 ns
The number of sub pulses in phase code keying signal
8191, 2047, 255
Height range
0 – 100 km
The permission on a vertical on the Rayleigh
2m
Nominal target pulse capacity of the transmitter
20 25 W
Input signal power
510 mW
Average power consumption
7W
Antenna length
1350 mm
Overall weight
3.5 kg
Main parameters of operating modes of the radar LPR
Operating
mode
Height
range,
km
The number of subpulses in a signal
Signal
duration, T (μs)
Energy gain,
dB
1
120 – 30
8191
220
39 (20)
2
60 – 10
2047
55
34 (17)
3
20 – 1
255
6.8
24 (12)
4
1.5– 0
1
26,710-3
0
Probing signal of device LPR and its spectrum
S(N)
N
•
Spectra of a device DPR signal: by a green line the spectrum of an individual radio
impulse, dark blue – code keying signal of 2047 sub pulses is shown
Device LPR information capacity
Operating
mode
Meassurement
capacity,
bytes
Operating
time, min
Quasi synchronous
orbit
1
57024
180
120
4
26.1
Quasi synchronous
orbit
2
16896
5
600
6
58.1
Landing (up tо 1 km)
3
4224
10
1200
1
4.8
Landing (lower 1 km)
4
2112
10
1200
1
2.4
Phobos surface
1,2,3,4
≈20064
1*4
10
1*4
0.8
Place of experiment
Total
The
number of
meassurements
per session
The number
of sessions
Operating
mode
total
capacity,
Mb
92.1
Modeling of a LPR signal restoration (М=2047)
at a signal to noise ratio -15dB is shown
U(N)
N
U(N)
N
Modeling of a LPR signal restoration (М=2047)
at a signal to noise ratio -15dB is shown
U(N)
N
U(N)
N
Thanks for attention