CN102841346B - Method for detecting distance and speed based on Hartley baseband signal - Google Patents

Abstract

The invention discloses a method for detecting a distance and a speed based on a Hartley baseband signal. The method is adopted for solving the technical problem of the traditional radar that the detecting speed is low because a signal is sent for the second time after an echo of the signal sent for the first time is received. According to the technical scheme, a string of Hartley baseband signals is continuously sent, echo integrals of the string of Hartley baseband signals are subjected to inter-signal decoding after echoes are effectively authenticated, and the echoes of the baseband signals sent at different time periods are separated. The detection efficiency of the radar is increased.

Description

Distance based on Hartley baseband signal, speed detection method

Technical field

The invention belongs to radar tracking performance field, particularly relate to a kind of distance, speed detection method based on Hartley baseband signal.

Background technology

Radar is the electronic equipment that utilizes microwave region electromagnetic wave detection target, it in modern war operational chain of command, is the detection means of obtaining information, to collect the sensor of various military informations, it have the target range of discovery far away, measure coordinates of targets and other parametric speed are fast, can all weather operations etc. feature; When radar system is contained in all kinds of optimal in structures such as aircraft, naval vessel, battlebus, guided missile, becoming the guarantee of weaponry to target enforcement precision strike, is the multiplier of its operational performance of performance; Radar is militarily widely used in the aspects such as warning, guiding, weapon control, scouting, measurement, navigation guarantee, enemy and we's identification and meteorological observation, is a kind of important military electronic technology equipment; The classification of radar has various ways, divides and has ground radar, airborne radar etc. according to place platform; Divide and have metre wave radar, microwave radar etc. according to operation wavelength; Divide and have intelligence radar, instrumentation radar, early warning radar, weather radar, fire control or fire control radar, artillery radar, guidance radar etc. according to purposes; Divide and have two dimensional Radars, three-dimensional radar etc. according to the target component of measuring; Divide and have pulsed radar, continuous wave radar etc. according to signal form; Concrete purposes and the structure of various radars are not quite similar, but citation form is consistent, comprise five elements: transmitter, emitting antenna, receiver, receiving antenna and display; Also have power-supply device, data record apparatus, anti-interference equipment, utility appliance etc.; Radar role is similar with eyes, and its principle is that the transmitter of radar equipment passes through day bundle of lines electromagnetic wave energy directive space a direction, is in the object that this side up and encounters electromagnetic wave back reflection; Radar antenna receives this reflection wave, delivers to receiving equipment and processes, and extracts some information of relevant this object, if target object is to distance, range rate or the radial velocity of radar, orientation, height etc.; Measuring distance is actual be measure transmit and echoed signal between mistiming, because electromagnetic wave is with light velocity propagation, just can be converted into accordingly the accurate distance of target; Measurement target orientation is to utilize the sharp-pointed orientation wave beam of antenna to measure, and measures the elevation angle and measures by narrow elevation beam, just can calculate object height according to the elevation angle and distance; Measuring speed is radar according to the frequency Doppler effect principle that has relative motion to produce between self and target; The target echo frequency that radar receives is different from radar transmitter frequency, and both differences are called Doppler frequency; From Doppler frequency, one of extractible main information is the range rate between radar and target; In the time that target and interference noise are present in the same space resolution element of radar simultaneously, radar utilize the difference of Doppler frequency between them can be from interference noise detection and tracking target; The advantage of radar is all can survey remote target, and be not subject to stopping of mist, Yun Heyu day and night, has feature round-the-clock, round-the-clock, and has certain penetration capacity; Therefore, it not only becomes military requisite electronics, and is widely used in socio-economic development if weather forecast, resource detection, environmental monitoring and scientific research are as celestial body research, atmospheric physics, ionospheric structure research etc.; Spaceborne and airborne synthetic aperture radar has become very important sensor in current remote sensing field, can survey the accurate shape on ground taking ground as the radar of target, and its spatial resolution can reach several meters to tens meters, and and range-independence; Radar has shown good application potential at aspects such as freshwater monitoring, sea ice monitoring, soil moisture investigation, forest assessment, geologic examinations.But, radargrammetry apart from time conventionally need to wait for to receive when sending again next measurement after the echoed signal that pre-test transmits and transmit, by measurement transmit and echoed signal between mistiming calculate distance; This scheme speed of detection is low, seriously restricts the performance of radar performance.

Summary of the invention

For overcome existing radar for the second time transmitted signal need to wait for and receive for the first time transmitted signal echo and cause the deficiency that speed of detection is low, the invention provides a kind of distance, speed detection method based on Hartley baseband signal.The method adopts and sends continuously a string Hartley baseband signal, effectively after certification, again the echo integration of a string Hartley baseband signal is carried out to the decoding between signal by echo, by the baseband signal echo free processing of different time transmission, can improve the detection efficiency of radar.

The technical solution adopted for the present invention to solve the technical problems is: a kind of distance, speed detection method based on Hartley baseband signal, is characterized in comprising the following steps:

Step 1, transmitted signal are:

$\begin{array}{c}\underset{i=-n}{\overset{n}{\mathrm{\Σ}}}\mathrm{cas}\left\{\mathrm{i\ω}\right[t+(T_{\mathrm{ini}(-n)}+T_{-n})-\underset{j=-n}{\overset{i}{\mathrm{\Σ}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})\left]\right\}\left\{u\right[t+(T_{\mathrm{ini}(-n)}+T_{-n})-\underset{j=-n}{\overset{i}{\mathrm{\Σ}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})]-\\ u[t+(T_{\mathrm{ini}(-n)}+T_{-n})-\underset{j=-n}{\overset{i+1}{\mathrm{\Σ}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})]\}\end{array}$

In formula, cas (i ω t)=cos (i ω t)+sin (i ω t),

$u\left(t\right)=\left\{\begin{array}{cc}0& t<0\\ 1& t\&GreaterEqual;0\end{array}\right.,$

ω is angular frequency, and t>=0 is the time, and n is integer, T _inijfor cas (j ω origin identification symbol duration t), T _endjfor cas (j ω ending identifier duration t), T _jfor cas, (j ω is the lasting cycle of signal t);

Coded system is: cas (origin identification t) of n ω symbol, cas (and n ω t), cas (n ω ending identifier t), cas (origin identification t) of i ω symbol, cas (i ω t), cas (i ω ending identifier t),, cas (origin identification t) of n ω symbol, cas (n ω t), cas (n ω ending identifier t);

Step 2, authenticate cas (origin identification t) of i ω symbol and ending identifier and echo time by echoed signal;

Step 3, according to function

${\&Integral;}_{t_0}^{t_1}{\mathrm{\&phi;}}^2\left(t\right)\mathrm{dt}={\&Integral;}_{t_0}^{t_1}{\mathrm{\&psi;}}^2\left(t\right)\mathrm{dt}$

Speed, echo time to target travel are estimated;

In formula, the echo function that φ (t) is radar detection,

$\begin{array}{c}\mathrm{\&psi;}\left(t\right)=\underset{i=-n}{\overset{n}{\mathrm{\&Sigma;}}}\mathrm{cas}\left\{i(1+\mathrm{signr}\frac{{2v}_{\mathrm{ri}}}{c})\mathrm{\&omega;}\right[t+(T_{\mathrm{ini}(-n)}+T_{-n})-{\mathrm{\&Delta;T}}_j-\underset{j=-n}{\overset{i}{\mathrm{\&Sigma;}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})\left]\right\}\&CenterDot;\\ \left\{u\right[t+(T_{\mathrm{ini}(-n)}+T_{-n})-{\mathrm{\&Delta;T}}_j-\underset{j=-n}{\overset{i}{\mathrm{\&Sigma;}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})]-u[t+(T_{\mathrm{ini}(-n)}+T_{-n})-{\mathrm{\&Delta;T}}_j-\underset{j=-n}{\overset{i+1}{\mathrm{\&Sigma;}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})\left]\right\}\end{array}$

Δ T _jin order to receive cas, (j ω is the time delay of signal t), and c is the light velocity, and the angle between radar line of sight and target velocity vector is θ, v _ri=v _icos θ, v _ibe the amplitude of the relative radar speed vector of target of i subwave detection, in the time that gtoal setting radar moves, between radar and target, distance reduces, and its echo frequency equals transmission frequency and adds that Doppler shift is signr=1, and echo frequency is greater than emission signal frequency; In the time that target is moved away from radar, between radar and target, distance increases, and its echo frequency equals transmission frequency and deducts Doppler shift, i.e. signr=-1, and echo frequency is less than emission signal frequency; In the time of target transfixion, there is not Doppler effect, i.e. signr=0.

The invention has the beneficial effects as follows: send continuously a string Hartley baseband signal owing to adopting, effectively after certification, again the echo integration of a string Hartley baseband signal is carried out to the decoding between signal by echo, by the baseband signal echo free processing of different time transmission, improve the detection efficiency of radar.

Below in conjunction with embodiment, the present invention is elaborated.

Embodiment

The distance, the speed detection method concrete steps that the present invention is based on Hartley baseband signal are as follows:

1, transmitted signal is:

$\begin{array}{c}\underset{i=-n}{\overset{n}{\mathrm{\&Sigma;}}}\mathrm{cas}\left\{\mathrm{i\&omega;}\right[t+(T_{\mathrm{ini}(-n)}+T_{-n})-\underset{j=-n}{\overset{i}{\mathrm{\&Sigma;}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})\left]\right\}\left\{u\right[t+(T_{\mathrm{ini}(-n)}+T_{-n})-\underset{j=-n}{\overset{i}{\mathrm{\&Sigma;}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})]-\\ u[t+(T_{\mathrm{ini}(-n)}+T_{-n})-\underset{j=-n}{\overset{i+1}{\mathrm{\&Sigma;}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})]\}\end{array}$

In formula: cas (i ω t)=cos (i ω t)+sin (i ω t),

$u\left(t\right)=\left\{\begin{array}{cc}0& t<0\\ 1& t\&GreaterEqual;0\end{array}\right.,$

ω is angular frequency, and t>=0 is the time, T _inijfor cas (j ω origin identification symbol duration t), T _endjfor cas (j ω ending identifier duration t), T _jfor cas, (j ω is the lasting cycle of signal t), and symbol definition is identical in full;

Coded system is: cas (origin identification t) of n ω symbol, cas (and n ω t), cas (n ω ending identifier t), cas (origin identification t) of i ω symbol, cas (i ω t), cas (i ω ending identifier t),, cas (origin identification t) of n ω symbol, cas (n ω t), cas (n ω ending identifier t);

2, authenticate cas (i ω origin identification symbol and ending identifier and echo time t) by echoed signal;

3, according to function

$\underset{k=1}{\overset{M}{\mathrm{\&Sigma;}}}{\mathrm{\&phi;}}^2\left(t\right)\mathrm{\&Delta;t}=\underset{k=1}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{\&psi;}}^2\left(t\right)\mathrm{\&Delta;t}$

Can estimate the speed of target travel, echo time;

Wherein, the echo function that φ (t) is radar detection, Δ t=(t ₁-t ₀)/M, M is integer;

$\begin{array}{c}\mathrm{\&psi;}\left(t\right)=\underset{i=-n}{\overset{n}{\mathrm{\&Sigma;}}}\mathrm{cas}\left\{i(1+\mathrm{signr}\frac{{2v}_{\mathrm{ri}}}{c})\mathrm{\&omega;}\right[t+(T_{\mathrm{ini}(-n)}+T_{-n})-{\mathrm{\&Delta;T}}_j-\underset{j=-n}{\overset{i}{\mathrm{\&Sigma;}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})\left]\right\}\&CenterDot;\\ \left\{u\right[t+(T_{\mathrm{ini}(-n)}+T_{-n})-{\mathrm{\&Delta;T}}_j-\underset{j=-n}{\overset{i}{\mathrm{\&Sigma;}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})]-u[t+(T_{\mathrm{ini}(-n)}+T_{-n})-{\mathrm{\&Delta;T}}_j-\underset{j=-n}{\overset{i+1}{\mathrm{\&Sigma;}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})\left]\right\}\end{array}$

Δ T _jin order to receive cas, (j ω is the time delay of signal t), and c is the light velocity, and the angle between radar line of sight and target velocity vector is θ, v _ri=v _icos θ, v _ibe the amplitude of the relative radar speed vector of target of i subwave detection, in the time that gtoal setting radar moves, between radar and target, distance reduces, and its echo frequency equals transmission frequency and adds that Doppler shift is signr=1, and echo frequency is greater than emission signal frequency; Otherwise in the time that target is moved away from radar, between radar and target, distance increases, its echo frequency equals transmission frequency and deducts Doppler shift, i.e. signr=-1, and echo frequency is less than emission signal frequency; In the time of target transfixion, there is not Doppler effect, i.e. signr=0.

Claims (1)

1. the distance based on Hartley baseband signal, a speed detection method, is characterized in that comprising the following steps:

Step 1, transmitted signal are:

$\begin{array}{c}\underset{i=-n}{\overset{n}{\mathrm{\&Sigma;}}}\mathrm{cas}\left\{\mathrm{i\&omega;}\right[t+(T_{\mathrm{ini}(-n)}+T_{-n})-\underset{j=-n}{\overset{i}{\mathrm{\&Sigma;}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})\left]\right\}\left\{u\right[t+(T_{\mathrm{ini}(-n)}+T_{-n})-\underset{j=-n}{\overset{i}{\mathrm{\&Sigma;}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})]-\\ u[t+(T_{\mathrm{ini}(-n)}+T_{-n})-\underset{j=-n}{\overset{i+1}{\mathrm{\&Sigma;}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})]\}\end{array}$ In formula, cas (i ω t)=cos (i ω t)+sin (i ω t),

$u\left(t\right)=\left\{\begin{array}{cc}0& t<0\\ 1& t\&GreaterEqual;0\end{array}\right.,$

ω is angular frequency, and t>=0 is the time, and n is integer, T _inijfor cas (j ω origin identification symbol duration t), T _endjfor cas (j ω ending identifier duration t), T _jfor cas, (j ω is the lasting cycle of signal t);

Coded system is: cas (origin identification t) of n ω symbol, cas (and n ω t), cas (n ω ending identifier t), cas (origin identification t) of i ω symbol, cas (i ω t), cas (i ω ending identifier t),, cas (origin identification t) of n ω symbol, cas (n ω t), cas (n ω ending identifier t);

Step 2, authenticate cas (origin identification t) of i ω symbol and ending identifier and echo time by echoed signal;

Step 3, according to function

${\&Integral;}_{t_0}^{t_1}{\mathrm{\&phi;}}^2\left(t\right)\mathrm{dt}={\&Integral;}_{t_0}^{t_1}{\mathrm{\&psi;}}^2\left(t\right)\mathrm{dt}$

Speed, echo time to target travel are estimated;

In formula, the echo function that φ (t) is radar detection,

$\begin{array}{c}\mathrm{\&psi;}\left(t\right)=\underset{i=-n}{\overset{n}{\mathrm{\&Sigma;}}}\mathrm{cas}\left\{i(1+\mathrm{signr}\frac{{2v}_{\mathrm{ri}}}{c})\mathrm{\&omega;}\right[t+(T_{\mathrm{ini}(-n)}+T_{-n})-{\mathrm{\&Delta;T}}_j-\underset{j=-n}{\overset{i}{\mathrm{\&Sigma;}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})\left]\right\}\&CenterDot;\\ \left\{u\right[t+(T_{\mathrm{ini}(-n)}+T_{-n})-{\mathrm{\&Delta;T}}_j-\underset{j=-n}{\overset{i}{\mathrm{\&Sigma;}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})]-u[t+(T_{\mathrm{ini}(-n)}+T_{-n})-{\mathrm{\&Delta;T}}_j-\underset{j=-n}{\overset{i+1}{\mathrm{\&Sigma;}}}(T_{\mathrm{inij}}+T_j+T_{\mathrm{endj}})\left]\right\}\end{array}$

Δ T _jin order to receive cas, (j ω is the time delay of signal t), and c is the light velocity, and the angle between radar line of sight and target velocity vector is θ, v _ri=v _icos θ, v _ibe the amplitude of the relative radar speed vector of target of i subwave detection, in the time that gtoal setting radar moves, between radar and target, distance reduces, and its echo frequency equals transmission frequency and adds that Doppler shift is signr=1, and echo frequency is greater than emission signal frequency; In the time that target is moved away from radar, between radar and target, distance increases, and its echo frequency equals transmission frequency and deducts Doppler shift, i.e. signr=-1, and echo frequency is less than emission signal frequency; In the time of target transfixion, there is not Doppler effect, i.e. signr=0.