29-05-2012, 01:04 PM
CELL DARS
[attachment=23327]
ABSTRACT:
The RADARs were and are considered as one of the most effective boons for the defense. But with the conditions turning disastrously advanced, the present radars need a serious make over.
So, here is CELLDAR (cellular radar), the best solution ever thought of.
Unlike the conventional RADARs using a separate transmitter and receiver, celldar uses a third party transmitter, for instance FM radio signals, Digital audio broadcasting signals, Digital video broadcasting signals etc and the cell phone itself acts as a receiver, thus leading to cost reduction and circuit simplicity.
This third party transmitter radiation, when emitted from their towers, strikes the required object and when reflected back, is collected across the receiver. Then by calculating the difference between the time period of waves obtained directly from the receiver to that of the reflected waves from the object results in the range, location and speed of the object.
Hence we can make the foes sweat by introducing the state of the art RADAR system.
INTRODUCTION:
The concept of CELLDARs is introduced with an intention to bring in a new dimension in RADARs.
Basically, CELLDAR is derived from the concept of Passive Radar.
Celldar is a Bistatic radar and hence uses a separate transmitter and receiver, converse to that of a Monostatic radar having collocated transmitter and receiver.
A few among the list of advantages of celldars are that the cost of production can be reduced up to 1 to 1.5 lakhs when compared to a whooping amount of 20 to 30 lakhs shed for the manufacture of conventional radars and by using a third party transmitter and the cell phone itself as the receiver, the circuit becomes really simplified.
APPROACH:
In Celldar, there is no dedicated transmitter. Instead, the receiver uses third-party transmitters in the environment, and measures the time difference of arrival between the signal arriving directly from the transmitter and the signal arriving via reflection from the object. This allows the Bistatic range of the object to be determined. These allow the location, heading and speed of the object to be calculated. In some cases, multiple transmitters and/or receivers can be employed to make several independent measurements of bistatic range, Doppler and bearing and hence significantly improve the final track accuracy.
CELLDAR systems have been developed that exploit the following sources of illumination:
Analog television signals.
FM radio signals.
GSM base stations.
Digital audio broadcasting signals.
Digital video broadcasting signals.
High definition television signals.
Satellite signals have generally been found to be inadequate for CELLDAR use: either because the powers are too low, or because the orbits of the satellites are such that illumination is too infrequent. The possible exception to this is the exploitation of satellite-based radar and satellite radio systems.
PRINCIPLE:
In a conventional radar system, the time of transmission of the pulse and the transmitted waveform are exactly known. This allows the object range to be easily calculated and for a matched filter to be used to achieve a signal-to-noise ratio in the receiver. A Celldar does not have this information directly and hence must use a dedicated receiver channel (known as the "reference channel") to monitor each transmitter being exploited, and dynamically sample the transmitted waveform. A Celldar typically employs the following processing steps:
[attachment=23327]
ABSTRACT:
The RADARs were and are considered as one of the most effective boons for the defense. But with the conditions turning disastrously advanced, the present radars need a serious make over.
So, here is CELLDAR (cellular radar), the best solution ever thought of.
Unlike the conventional RADARs using a separate transmitter and receiver, celldar uses a third party transmitter, for instance FM radio signals, Digital audio broadcasting signals, Digital video broadcasting signals etc and the cell phone itself acts as a receiver, thus leading to cost reduction and circuit simplicity.
This third party transmitter radiation, when emitted from their towers, strikes the required object and when reflected back, is collected across the receiver. Then by calculating the difference between the time period of waves obtained directly from the receiver to that of the reflected waves from the object results in the range, location and speed of the object.
Hence we can make the foes sweat by introducing the state of the art RADAR system.
INTRODUCTION:
The concept of CELLDARs is introduced with an intention to bring in a new dimension in RADARs.
Basically, CELLDAR is derived from the concept of Passive Radar.
Celldar is a Bistatic radar and hence uses a separate transmitter and receiver, converse to that of a Monostatic radar having collocated transmitter and receiver.
A few among the list of advantages of celldars are that the cost of production can be reduced up to 1 to 1.5 lakhs when compared to a whooping amount of 20 to 30 lakhs shed for the manufacture of conventional radars and by using a third party transmitter and the cell phone itself as the receiver, the circuit becomes really simplified.
APPROACH:
In Celldar, there is no dedicated transmitter. Instead, the receiver uses third-party transmitters in the environment, and measures the time difference of arrival between the signal arriving directly from the transmitter and the signal arriving via reflection from the object. This allows the Bistatic range of the object to be determined. These allow the location, heading and speed of the object to be calculated. In some cases, multiple transmitters and/or receivers can be employed to make several independent measurements of bistatic range, Doppler and bearing and hence significantly improve the final track accuracy.
CELLDAR systems have been developed that exploit the following sources of illumination:
Analog television signals.
FM radio signals.
GSM base stations.
Digital audio broadcasting signals.
Digital video broadcasting signals.
High definition television signals.
Satellite signals have generally been found to be inadequate for CELLDAR use: either because the powers are too low, or because the orbits of the satellites are such that illumination is too infrequent. The possible exception to this is the exploitation of satellite-based radar and satellite radio systems.
PRINCIPLE:
In a conventional radar system, the time of transmission of the pulse and the transmitted waveform are exactly known. This allows the object range to be easily calculated and for a matched filter to be used to achieve a signal-to-noise ratio in the receiver. A Celldar does not have this information directly and hence must use a dedicated receiver channel (known as the "reference channel") to monitor each transmitter being exploited, and dynamically sample the transmitted waveform. A Celldar typically employs the following processing steps: