JP2002133776A - Recording/reproducing device and recording/reproducing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording/reproducing device and a recording/reproducing method capable of converting analog signals into digital signals to be recorded and extracting data at an accurate time when reproducing the recorded data. SOLUTION: This recording/reproducing device is provided with a GPS(global positioning system) receiver 12 receiving the time data from a GPS satellite, an A/D(analog-digital) converter 11 generating sampling data by sampling inputted analog signals and converting them into digital signals in sequence, a recording means 13 periodically embedding the time data from the GPS receiver 12 into the sampling data sent from the A/D converter 11 in sequence and recording them on a storage medium 30, and a reproducing means 13 reading the sampling data recorded on the storage medium 30 by the recording means 13 according to the instruction from a reproduction instructing section 31 and sending them to a processing analyzer 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus and a recording / reproducing method for recording and reproducing sampling data obtained by converting an analog signal into a digital signal. The present invention relates to a technology for recording and reproducing data in association with each other.

[0002]

2. Description of the Related Art Conventionally, there has been known a recording / reproducing apparatus which records data received one after another while pressing a time stamp, and reproduces data at a desired time from the recorded data. This recording / reproducing apparatus is used for the following purposes.

For example, the same radio signal is received and recorded by two recording / reproducing devices at two different points on the earth, and then the recorded data is reproduced to compare data at the same time. By doing so, the time difference of arrival of radio waves is obtained, and thus the height of the ionosphere is measured. Therefore, in this recording / reproducing apparatus, it is necessary to record the received signal based on the same time reference.

As such a recording / reproducing apparatus, for example, a magnetic tape apparatus for recording received data on a magnetic tape as a digital signal has been known. In this magnetic tape device, when it is necessary to record a time signal with high accuracy, generally, the time signal is recorded as an analog signal using an analog recording head independent of a digital recording head. .

[0005]

However, when recording is performed using two magnetic heads such as a digital recording head and an analog recording head, a time recording error occurs due to a mechanical error between the two recording heads. I do. Therefore, it is not appropriate to use the time information recorded on the magnetic tape as a highly accurate time reference.

On the other hand, when a high-precision time reference is required, a method of recording by embedding a time signal in digital data to be recorded may be adopted. However, in general, A / A for converting an analog signal into a digital signal is used.
The sampling clock of the D converter and the clock of the time are not necessarily synchronized. Therefore, the time information recorded by such a method is not accurate, and is not suitable for use as a time reference.

Further, if time information is added to each sampling data output from the A / D converter, the amount of data to be recorded increases, which is not preferable.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. An object of the present invention is to convert an analog signal into a digital signal and record it, and to reproduce the recorded data at an accurate time. An object of the present invention is to provide a recording / reproducing apparatus and a recording / reproducing method capable of extracting data.

[0009]

To achieve the above object, a recording / reproducing apparatus according to the present invention comprises: a GPS receiver for generating time data based on a signal received from a GPS satellite;
An A / D converter that samples input analog signals and sequentially converts them into digital signals to generate sampling data; and a sampling data that is sequentially sent from the A / D converter to the GPS receiver. Recording means for recording on a recording medium while periodically embedding time data.

According to this recording / reproducing apparatus, high-accuracy and high-accuracy time data from a GPS receiver is recorded on a recording medium while periodically embedded in sampling data sequentially sent from an A / D converter. Therefore, at the time of reproduction, by extracting recorded data based on the embedded time data, data at an accurate time can be extracted.

According to the recording / reproducing method of the present invention, time data is generated based on a received signal from a GPS satellite, an input analog signal is sampled, and a digital signal is input. , The sampling data is sequentially generated, and the time data is recorded on a recording medium while periodically embedding the time data in the sequentially generated sampling data.

According to this recording / reproducing method, high-precision and high-accuracy time data from a GPS satellite is recorded on a recording medium while periodically embedded in sampling data to be sequentially generated. By extracting recorded data based on the data, it is possible to extract data at an accurate time.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a recording / reproducing apparatus and a recording / reproducing method according to an embodiment of the present invention will be described in detail with reference to the drawings. In the following, for ease of understanding, description will be made using specific numbers, but these numbers are merely examples.

FIG. 1 is a block diagram showing a configuration of a recording / reproducing apparatus according to an embodiment of the present invention. This recording / reproducing apparatus includes a receiver 10, an A / D converter 11, a GPS receiver 1
2. It comprises a recording / reproducing device 13 and a processing analyzer 14.

The receiver 10 receives a radio signal from, for example, an artificial satellite using an antenna (not shown). Then, an IF signal is generated based on the signal from this antenna, and the A / D
Send to converter 11. Note that the receiver 10 is not limited to a receiver that receives a radio signal from an artificial satellite, and a receiver that receives a terrestrial wave can be used.

The A / D converter 11 samples an IF signal transmitted as an analog signal from the receiver 10 with a signal having a sampling frequency fs, and outputs sampling data, for example, 8-bit discrete digital data. A signal used for sampling in the A / D converter 11 is controlled so as to synchronize with a reference clock signal from the GPS receiver 12.

The GPS receiver 12 receives a GPS satellite signal from the GPS satellite 20 through an antenna (not shown). Then, a reference clock signal (corresponding to the reference frequency clock of the present invention) and a reference time signal synchronized with the reception signal from the antenna are generated. The reference clock signal generated by the GPS receiver 12 is supplied to the A / D converter 11. This reference clock signal has a frequency of, for example, 10 MHz.
Pulse signal.

The reference time signal generated by the GPS receiver 12 is supplied to a recording / reproducing device 13. The reference time signal is a signal including a pulse generated once per second, that is, a 1 pps pulse signal.

The recording / reproducing device 13 corresponds to the recording means and the reproducing means of the present invention. The recording / reproducing device 13 receives the sampling data from the A / D converter 11 and assembles a frame synchronized with a reference time signal from the GPS receiver 12. Then, the assembled frame is stored in the recording medium 3.
0 is digitally recorded sequentially. As the recording medium 30,
A semiconductor memory, a magnetic medium such as a magnetic tape or a magnetic disk, or the like can be used.

FIG. 2 shows the data format of the frame. One frame is composed of additional data and sampling data. The additional data is composed of a frame synchronization word (UW) and time data.

The frame synchronization word (UW) is composed of a specific bit pattern (unique word) and is used to represent the head of a frame. The time data is G
This is data representing the generation time of the reference time signal from the PS receiver 12. The sampling data is, as described above,
This is data output from the A / D converter 11.

The recording / reproducing device 13 is provided with a reproduction instructing section 31. The reproduction instructing unit 31 corresponds to the instruction unit of the present invention, and is used to instruct a reproduction start time and a reproduction end time when reproducing the contents of the recording medium 30. The recording / reproducing device 13 takes out the sampling data in the range specified by the reproduction start time and the reproduction end time from the recording medium 30 and reproduces the data.

The processing analyzer 14 temporarily stores the data taken out from the recording medium 30 and reproduced by the recording / reproducing device 13, and performs processing such as analysis based on the stored data. The range extracted from the recording medium 30 is determined by the reproduction start time and the reproduction end time instructed by the reproduction instructing unit 31 as described above.

Next, the operation of the recording / reproducing apparatus according to the embodiment of the present invention configured as described above will be described.

First, the recording operation will be described. As described above, the GPS receiver 12 supplies the 1 pps reference time signal to the recording / reproducing device 13 and supplies the 10 MHz reference clock signal to the A / D converter 11. A / D converter 1
1 is a reference clock signal of 10 MHz.
The IF signal from 0 is sampled and A / D conversion is performed. Here, it is assumed that 8-bit A / D conversion is performed as an example.

The sampling data obtained by the A / D conversion is generated by the A / D converter 11 inside the A / D converter 11.
The data is transferred to the recording / reproducing device 13 using a recording data transfer clock of 0.24 MHz.

The recording data transfer clock is generated by synchronizing the phase with a 10 MHz reference clock signal from the GPS receiver 12 by a PLL (Phase Lock Loop). As a result, the sampling data is transferred to the recording / reproducing device 13 at a transfer rate of 10.24 MB / s.

A framing circuit (not shown) included in the recording / reproducing unit 13 assembles a frame for each 1 pps pulse in accordance with a reference time signal from the GPS receiver 12. 1
There are 10M samplings in the frame, that is, 10M
A / D converted sampling data of bytes and 24
Additional data corresponding to 0 kbytes is included. As described above, the additional data includes a synchronization word (UW) for frame synchronization and time data at the time when a 1 pps pulse is generated. The frame generated in this way is sent to the recording medium 30 and recorded.

Next, the reproducing operation will be described with reference to the flowchart shown in FIG. In this reproduction operation, it is assumed that the sampling data in the time zone specified by the user is reproduced.

In this reproducing operation, first, a data retrieval start time and an end time are designated (step S1).
0). This designation is made by inputting up to the date, month, day, hour, minute, and second by the reproduction instruction unit 31. In this case, since the sampling frequency is 10 MHz, it is possible to specify with a resolution of 100 ns.

For example, February 11, 2000, 13: 5
Seconds can be specified up to seven digits after the decimal point, such as 5 minutes 14.123567 seconds. In the following, for simplicity of description, a case where 14.12345667 seconds is set as the reproduction start point will be described.

Next, the frame is synchronized with the synchronization word (UW) (step S11). Thereby, the head of the frame is searched. Next, the time data of the frame and the start time specified in step S10 are compared in a range up to year, month, day, hour, minute, and second (step S12).

Therefore, data after the decimal point in the order of seconds is not compared. As a result of this comparison, if it is determined that they do not match, the sequence returns to step S11, the frame is synchronized with the next frame, and the same processing is repeated thereafter.

If it is determined in step S12 that the comparison results match during the repetitive execution of steps S11 and S12, it is recognized that the target frame has been searched, and the capture start position is determined. (Step S13). That is, in the above example, it is determined that the 1234567-th sampled data of the searched frame is the data of the capturing start position.

Next, the capturing end position is determined in the same manner as in step S13 (step S1).
4). Next, the sampling data at the capturing start position is captured (step S15).

Next, it is checked whether or not the processing is completed (step S16). That is, it is checked whether or not the sampling data specified in step S14 has been captured. Here, if it is determined that the processing is not to be terminated, the sequence returns to step S15, the next sampling data is fetched, and the same processing is repeated thereafter.

During the repetition of steps S15 and S16, if it is determined in step S16 that the sampling has been completed, it is recognized that the sampling data of the designated range has been completely captured, and Is sent to the processing analyzer 14 as one file (step S17). Thus, the reproducing operation is completed.

As described above, according to the recording / reproducing apparatus according to this embodiment, by giving time information in units of one second as synchronization additional information to the frame in units of one second, the time resolution in units of sampling can be obtained. A mechanism that can easily and accurately capture data has been described.

Further, since the time data from the GPS receiver is used as the reference time, almost the same time reference can be obtained even at two different locations on the earth. It is valid.

As described above, in the present invention, a desired unique effect can be obtained by a combination thereof based on existing technologies.

That is, A / D conversion of an analog signal is performed using a high-precision reference clock signal from the GPS receiver 12 to form a frame whose recording data format is synchronized with the pulse of the reference time signal from the GPS receiver 12. To record on the recording medium 30.

At the time of reproduction, frame synchronization is performed on the sampling data read from the recording medium 30, and the number of samplings from the start point of the sampling data of the frame is counted to obtain a capture start point. With this configuration, it is possible to extract sampling data from a time arbitrarily specified in the resolution of the sampling frequency and to make a file for signal processing.

This makes it extremely easy to collect data at a plurality of different points and to compare and analyze them off-line.

The recording / reproducing apparatus and the recording / reproducing method according to the present invention are not limited to the recording / reproducing apparatus and the recording / reproducing method according to the above-described embodiments. In the embodiment described above, the analog signal from the receiver 10 is A / D
Although configured to input to the converter 11, in the present invention,
Various devices that generate analog signals that change over time can be used in place of the receiver 10.

[0045]

As described in detail above, according to the present invention, an analog signal is converted into a digital signal and recorded, and when the recorded data is reproduced, data at an accurate time can be taken out. A reproducing apparatus and a recording / reproducing method can be provided.

More specifically, according to the present invention, high precision,
As a highly accurate time reference, time data based on a signal received from a GPS satellite is used, and a reference frequency clock synchronized with a signal received from the GPS satellite is used as a sampling clock of the A / D converter.

Then, a synchronizing word (UW) including time data is periodically embedded in the sampling data recorded on the recording medium, and at the time of reproduction, the synchronizing word including the time data is searched for a desired time range. The sampling data in is extracted. As a result, time information corresponding to each sampling data can be efficiently obtained without increasing the amount of time stamp data.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining frames used in the recording / reproducing apparatus according to the embodiment of the present invention.

FIG. 3 is a flowchart showing a reproducing operation of the recording / reproducing apparatus according to the embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 receiver 11 A / D converter 12 GPS receiver 13 recording / reproducing device 14 processing analyzer 20 GPS satellite 30 recording medium 31 reproduction instructing section

Claims (8)

[Claims] 1. A GPS receiver that generates time data based on a received signal from a GPS satellite, and an A / D converter that generates a sampled data by sampling an input analog signal and sequentially converting the sampled analog signal into a digital signal. Recording means for recording on a recording medium while periodically embedding time data from the GPS receiver in sampling data sequentially sent from the A / D converter. apparatus. 2. The recording means forms a frame by combining time data from the GPS receiver with sampling data sequentially received from the A / D converter after the time indicated by the time data, 2. The recording and reproducing apparatus according to claim 1, wherein the formed frames are sequentially recorded. 3. An instructing means for instructing a reproduction time, and a reproducing means for sequentially reproducing sampling data recorded on the recording medium from the time instructed by the instructing means, wherein the reproducing means comprises: Searching the recording medium for a frame including the sampling data recorded at the time specified by the specifying means, and reproducing the sampling data from a position calculated based on the time data included in the searched frame; The recording / reproducing apparatus according to claim 2, wherein: 4. The GPS receiver generates a reference frequency clock synchronized with the reception signal, and the A / D converter uses the reference frequency clock generated by the GPS receiver as a sampling clock. The recording / reproducing apparatus according to claim 1, wherein the recording / reproducing apparatus generates sampling data. 5. A receiving step of generating time data based on a received signal from a GPS satellite, a generating step of sequentially generating sampling data by sampling an input analog signal and converting it into a digital signal, Recording the recorded data on a recording medium while periodically embedding the time data in the sampled data. 6. The recording step includes forming a frame by combining the time data with the sequentially generated sampling data after the time indicated by the time data, and sequentially recording the formed frame. The recording / reproducing method according to claim 5, wherein: 7. An instructing step for instructing a reproducing time; and a reproducing step of sequentially reproducing sampling data recorded on the recording medium from the instructed time, wherein the reproducing step includes: A frame including the sampling data recorded at the time is searched from the recording medium, a reproduction start position of the sampling data is calculated based on the time data included in the searched frame, and the sampling data is calculated from the calculated reproduction start position. 7. The recording / reproducing method according to claim 6, wherein reproduction is performed. 8. The receiving step generates a reference frequency clock synchronized with a received signal from the GPS satellite, and the generating step generates sampling data using the generated reference frequency clock as a sampling clock. The recording / reproducing method according to any one of claims 5 to 7, wherein the recording / reproducing method is performed.