JPS60112335A - Picture data transmission system - Google Patents

Abstract

PURPOSE:To reduce the scale of the side of a data collection/reception station and to acquire quickly a picture data signal, by using a picture data processing means which divides the picture data signals into those of (n) series via sampling pulse signals of (n) series having an integer-fold cycle as mush as the sampling cycle. CONSTITUTION:A charge distribution corresponding to each observation scanning width on the ground surface is produced to each 1-dimensional charge coupling device for each of four observation wavelength areas A-D and in accordance with a photodetecting level distribution which is focused to each photodetecting part. The analog picture signal corresponding to the area A is sampled with a sampling signal of a cycle Ts by a sample and hold circuit 6. Furthermore the analog picture signal is divided into sample and hold picture signals of three series having a sampling cycle 3Ts via the smapling pulse signals of three series having a cycle 3Ts as well as a mutual time phase difference Ts. These sample and hold picture signals are supplied to modulators 10-12 respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image data system, and more particularly to an improvement in an image data transmission system for transmitting an image data signal acquired via a multi-element photoelectric conversion means to a remote data collection receiving station.

Conventionally, imaging means including, for example, multi-element photoelectric conversion means are mounted on all artificial satellites to capture images of a wide area of the earth's surface, and image data signals are transmitted from the artificial satellite to a receiving station for data collection on the ground. In an image data transmission method, for example, an image outputted from the multi-element photoelectric conversion means in accordance with a predetermined observation scanning width on the ground surface for each predetermined observation wavelength region including visible light, infrared rays, etc. Data signals are A-D for each observed wavelength region.
PSK (Pbase 5h
ift Keying ) modulation to be transmitted to the ground. In the case of this conventional example, if the resolution of the observation target on the ground surface is defined as, for example, about 25 m (meters), the PSK transmitted to the data collection receiving station on the ground
The required frequency bandwidth of the modulated signal has become as wide as 100 Mllz (megahertz), and as a data collection receiving station on the ground, a large-scale receiving facility with large diameter antennas is required. The image data received and processed by the receiving equipment is transmitted to many end users.
It takes a considerable number of days to distribute it properly, and it has the disadvantage that it is difficult to respond to the diverse needs of users.

An object of the present invention is to eliminate the above-mentioned drawbacks, and to provide an image data signal transmitter with a period of nTs (n is an integer greater than 1, and Ts is a sampling period), which is an image data signal output from a multi-element photoelectric conversion means. By providing an image data processing means that divides and divides into n series of image data signals via n series of sampling pulse signals, it is possible to reduce the size of the data collection receiving station and to reach a large number of end users. The object of the present invention is to provide an image data transmission system that can quickly acquire image data signals sent directly from an artificial satellite.

The image data transmission method of the present invention sequentially receives radiation or light rays emitted from a predetermined imaged object in each observation wavelength range including visible, infrared, and ultraviolet Kanakura, corresponding to a predetermined observation scanning width, An image data signal obtained through an imaging means including a predetermined optical imaging means and a predetermined multi-element photoelectric conversion means.

For each predetermined observation wavelength region in an image data transmission method for transmitting to a remote data collection receiving station.

Corresponding to at least one observation scan width or a plurality of partial observation scan widths, the image data signals output from the multi-element photoelectric conversion means have a mutual time phase difference of Ts, nT through n series of sampling pulse signals with a period of nTs (n is an integer greater than 1)
The image data transmitting side is provided with an image data processing means for dividing into n series of image data signals having a si sampling period.

The present invention will be explained in detail below with reference to all the drawings.

FIG. 1 is a block diagram showing the main parts of a data transmitting side applied to an embodiment of the present invention.

As shown in FIG. 1, the data transmission side of the present invention includes:
A photoelectric imaging section 1 and a photoelectric conversion section 2. 3. 4 and 5, sampling and holding circuits 6.78 and 9, and modulators 10, 11, 12, 13° 14.15, 16, 17
, 18, 19, 20 and 21, and a multiplex modulator 22,
A high frequency amplifier 23 is provided. This example is
This is an example of a case where an image data signal of the earth's surface captured by an artificial satellite is transmitted to the ground. Before explaining Figure 1, we will explain the radiometer on board the satellite.
The operational status of acquiring images of the ground surface will be briefly explained. FIGS. 4(a) and 4(b) show the observation scanning width on the earth's surface by the radiometer. The difference between FIGS. 4(a) and 4(b) is that the light receiving section provided in the radiometer is divided into a single section. , which are divided into three categories, and are defined from the operational aspect of earth surface observation using artificial satellites. In the figure, 108
and 109 each indicate the relative traveling direction of the artificial satellite with respect to the ground surface, and Wl and W2 indicate the observation scanning width in each case. Also, Figure 4 (
Symbols A, B, C and D in a) and (b) are
It represents four observation wavelength divisions corresponding to each observation scan width. That is, corresponding to the observation scanning width,
This means that image data corresponding to the four observation wavelength divisions A, B, C, and D are acquired at the same time.

Next, the operation of the image data transmitting side of the present invention will be explained in the case of FIG. 4 (al) mentioned above. In FIG. The light beam and the radiation 100 in the infrared region are transmitted by the optical imaging unit 1 to the above-mentioned A.

Spectrally divided into four observation wavelength regions of B, C and D,
Each observation wavelength range is equipped with a
The light is focused on a light receiving section composed of multi-element photoelectric conversion sections 2, 3, 4, and 5. The multi-element photoelectric conversion units 2, 3, 4, and 5 are usually constructed of charge-coupled devices, and in one embodiment of the image data transmission side of the present invention, a -dimensional charge-coupled device is used. ing. As mentioned above, for each of the four observation wavelength range divisions A, B, C, and D, the charge distribution corresponding to each observation scanning width on the earth's surface corresponds to the received light level distribution focused on each light receiving part. is generated in each one-dimensional charge-coupled device. These charge distributions are transmitted via a predetermined readout signal to the multi-element photoelectric conversion unit 2 for each observation wavelength region division as a series of analog image signals with a repetition period of a scanning time corresponding to the observation scanning width. ．． 3. 4 and 5, and the corresponding sampling/hold circuits 6, 7 . '8 and 9 are entered.

In the sampling/holding circuit 6, the analog image signal corresponding to the observed wavelength region classification A has a period Ts.
sampled by the sampling pulse signal of
Further, through three series of sampling pulse signals having a period of 3Tsi with a time phase difference e[of the Ts,
The signal is divided into three series of sampling/holding image signals having a sampling period of 3Ts6, and each signal is sent to a modulator 10.
11 and 12.

FIGS. 3(a), tb), (C) and (d) show that in the sampling/holding circuit 6, as described above,
FIG. 2 is a waveform diagram of an image signal during an operation process in which the analog image signal input from the multi-element photoelectric conversion unit 2 is output as three series of sampled and held image signals.

FIG. 3(a) shows the relative relationship between the light intensity signal 102 input to the multi-element photoelectric converter 2 and the image data signal 103 output from the photoelectric converter 2. FIG. 3(b)
, (C) and (d), sampling image signals are sequentially extracted from the sampled image signal 103 at intervals of 3TS, with a time difference of Ts, and from each sampling image signal, all valves of the predetermined hold circuit are extracted. 3 shows the wavelengths of three series of image data signals generated.

In Figure 1, the sampling and holding circuit.

In 7.8 and 9, the observed wavelength region classification B input from the multi-element photoelectric conversion units 3, 4 and 5, respectively, is exactly the same as in the case of the sampling/hold circuit 6a described above.
, C and D are output as three series of sampling and holding image signals, respectively, and are outputted to modulators 13, 14 and 15, and modulator 1, respectively.
6.17 and 18 and modulators 19.20 and 21.

Modulator 10, 11, 12, 13, 14, 15°16.1
7, 18, 19. In 20 and 21, the frequency f input to each modulator is determined by a predetermined modulation method.
In fZ+ f3+ f41f5. f6. f7. fB
, f9. The fso, fli, and f12 subcarrier signals are modulated by the corresponding sampling and holding signals, and these modulated output signals are input to the multiplexer 22, respectively. Multiplexer 22
multiplexes each modulated output signal described above and supplies it to the high frequency amplifier 23. The high frequency amplifier 23 amplifies the multiplexed radio signal to a predetermined level and outputs it as a transmission output signal 101. This output signal is sent to the data collection receiving station via a predetermined antenna.

FIGS. 2(a) and 2(b) are block diagrams showing the main parts of two examples of a data collection receiving station on the ground corresponding to the image data transmitting side of the above-mentioned artificial satellite. Figure 2 (
aJ is an image data signal obtained by receiving all the frequency multiplexed signals sent from the image data transmitting side,
Original image data signal over all observation wavelength divisions A, B, C, and D corresponding to each observation scan width (image data signal corresponding to sampling period Ts), or original image data signal in a specific observation wavelength region division The case of a large-scale data collection receiving station where the following information can be arbitrarily selected is shown. Moreover, FIG. 2(b) shows that the frequency-multiplexed signal is received and only in a specific observation wavelength region division. This shows the case of a small-scale data collection/reception station that regularly acquires and uses the sampling and holding image signal as an image data signal.

In FIG. 2(a), a frequency multiplexed signal 104 sent from an artificial satellite is sent to a receiving section 24 including a predetermined antenna.
is received, converted to a predetermined intermediate frequency, and input to the multiplex demodulator 25. In the multiplex demodulator 25, this intermediate frequency signal is demodulated in accordance with the angle modulation method on the image data transmitting side described above, and the frequency f1*f2 is
t f3* '4*fBe f6e f7* f8e
They are sent to subcarrier demodulators 26-1 to 12 as predetermined modulated signals for subcarrier signals corresponding to f9w hoe flll and f12, respectively. In the subcarrier demodulators 26-1 to 12, through a predetermined demodulation action,
Sampling and holding image signals corresponding to each are generated and input to the image data synthesis circuit 27. In the image data synthesis circuit 27, due to operational requirements,
A desired image data composite signal is selectively generated in response to differences such as when acquiring an image data composite signal in all observation wavelength region divisions, or when acquiring an image data composite signal in a specific observation wavelength region division, It is output as a predetermined image data signal 105.

Regarding the image data synthesis operation of the image data synthesis circuit 27 in Figure 2 (a), see Figure 3 ta), (b),
It can be easily understood by referring to (C) and (dl. That is, from the three sampling and holding image signals shown in FIG. 3(b), (C) and td), FIG. ) The original image data signal 1 shown in
In order to synthesize 02, the above three samplings and
3. Extracting each sampling link level when generating a hold image signal in time division at the leading edge of each sampling and holding image signal;
Three sampling image signals having a sampling period of Ts6 may be generated, these sampling image signals may be combined, and then converted into an analog signal.

In FIG. 2(b), a frequency multiplexed signal 106 sent from five artificial satellites is sent to a receiving section 28 including a predetermined antenna.
is received, converted to a predetermined intermediate frequency, and input to the multiplex demodulator 29. In the multiplex demodulator 29, this intermediate frequency band frequency multiplexed signal is demodulated in accordance with the above-mentioned angle modulation method on the image data transmission side.
The subcarrier signal is input to the subcarrier demodulator 30 corresponding to a specific frequency of the two subcarrier signals, for example, a subcarrier signal of frequency f5 in observation wavelength region classification B.

In the subcarrier demodulator 30, a sampling and holding image signal in observation wavelength region classification B is generated through a predetermined demodulation function, and is output as a predetermined image data signal 107.

In the above explanation, corresponding to FIGS. 2(a) and (b), the respective operations are explained in the case of a large-scale data collection receiving station and the case of a small-scale simple data collection receiving station. I explained the contents. The major difference and feature between these two receiving stations is that the large-scale data collection receiving station shown in Fig. 2(a) requires a large-diameter antenna, and the original image data signal in each observation wavelength region division is While the data can be acquired in the same way as with the conventional large-scale data collection receiving station, in the case of the simple data collection receiving station shown in Figure 2 (b), a small receiving antenna with a small diameter is sufficient. , and it is possible to simplify the overall configuration of the receiving station and its components. Therefore, if the latter receiving station configuration is used, it is possible to install a data collection receiving station extremely economically, and depending on the end user,
In many cases, the image data signal acquired by this simple data collection receiving station is both necessary and sufficient in terms of content and quality for data utilization. In other words, by applying the image data transmission method of the present invention, various types of receiving stations, including large-scale and small-scale ones, can be selected as data collection receiving stations in response to the necessity of image data utilization. This makes it possible to quickly and effectively provide image data to a large number of end users in response to the diversity in the use of image data.

In addition, when transmitting the original image data signal in all observation wavelength range divisions or a specific observation wavelength range division, as described above,
In the case of transmitting all sampled and held image signals in a specific observation wavelength region division, the size of the receiving antenna system at the data collection receiving station is essentially the same as the image data transmission system in the artificial satellite and the receiving system at the data collection receiving station. This largely depends on the transmission bandwidth of the image data transmission system that is formed. Considering the case where the orbital conditions of the satellites are the same, the above transmission bandwidth B is generally
is expressed by the following proportional expression.

L-Nb, N B oc (1) 2 In the above formula, L is the length of the observation scanning width on the ground surface,
Nb is the number of observation wavelength region divisions, Nq is the number of quantization bits,
W is the pixel size on the ground surface. This pixel size W corresponds to the resolution of an image captured by a radiometer mounted on an artificial satellite. For a typical example, w=2
For 5m (meter), transmission bandwidth B is 100MI
It has a wide band of approximately Lz (mega hertz), and the receiving antenna of the data collection receiving station is a large-sized one with an aperture diameter of 10 m. However, the pixel size W in the above equation (1) is proportional to the sampling period Ts for the original image data signal when viewed from the one image data transmission condition, and the above equation (1) has a bottom line as shown in the following equation. You can also forget.

That is, the transmission bandwidth B is inversely proportional to the sampling period Ts. Generally, the aperture diameter of the receiving antenna of the data collection receiving station is proportional to the square root of the above-mentioned transmission bandwidth B, so the aperture diameter of the receiving antenna is proportional to the increase/decrease ratio of the sampling period with respect to the original image data signal. Increase or decrease.

That is, as described above, in the four observation wavelength region divisions A, B, C, and D, compared to the case where the original image data signal transmitted at the sampling period Ts is In the classification, the above-mentioned (
As is clear from the formula 2), the opening diameter is reduced to %, which significantly reduces the size.

In addition, in the above-described embodiment of the present invention, the observation scanning width on the ground surface of the observation target was explained using the case shown in FIG. 4(a), but as shown in FIG. 4(b),
When the observation scanning width is divided into three, as is clear from equation (2), the length L of the observation scanning width is %, so the aperture diameter of the receiving antenna is further reduced to 1/V' It is downsized to T. In other words, in relation to the diversity of end users' use of image data, the scale of the data collection receiving station is determined according to the required observation wavelength range division, required image size, required observation area on the lichen surface, etc. The receiving antenna was significantly downsized. Moreover, even under the operating conditions of the radiometer shown in FIG. 4(b), each observation scan width section 1. The original image data signals of II and ■ are all observed wavelength region classification A.

At B, C and D, all image data signals are transmitted from satellites and can be acquired by providing a predetermined large-scale data collection receiving station.

As described in detail above, the present invention provides an original image data signal i with a sampling period Ts, n series of samplings with nT - total period on the image data signal transmitting side.
By providing an image data processing means that divides and divides the pulse signal into n series of image data signals, it is possible to reduce the size of the data collection receiving station and to reduce the number of endpoints.
This has the effect of allowing the user to quickly and economically acquire image data signals directly sent from the satellite.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the main parts of the data transmitting side applied to one embodiment of the present invention, and FIGS. 2(a) and (b) are two forms of the data collection receiving station applied to the present invention, respectively. Block diagram showing the main parts of the example, Figure 3 (al, (b),
FC+ and (d) are image data signal waveform diagrams for explaining the operation of the image data processing means, respectively, and FIGS. 4 (a) and (b) are diagrams showing the observation scanning width of the ground surface by the radiometer, respectively. . In the figure, 1... optical imaging section, 2-5... multi-element photoelectric conversion section, 6-9...
...Sampling/hold circuit. 10-21...--Modulator, 22...--Multiplexer-123...--High frequency amplifier, 24...
...Receiving section, 25...Multiple demodulator, 26
-1 to 12...Subcarrier demodulator, 27...
...Image data synthesis circuit, 28...Receiving section, 2
9...Multiple demodulator, 30...Subcarrier demodulator. (0-) 2nd Flash 1 W 3 Figure (A, B, C, ρ) ■ 1 ■ W/-1 (&) Figure 4

Claims (1)

[Claims] Emitted from a predetermined object to be imaged. An imager that sequentially receives radiation or light rays in each observation wavelength range including visible, infrared, and ultraviolet wavelengths corresponding to a predetermined observation scanning width, and includes a predetermined optical imaging means and a predetermined multi-element photoelectric conversion means. In an image data transmission method that transmits image data signals acquired via IT to a remote data collection receiving station, each predetermined observation wavelength region is divided into at least one observation scanning width or a plurality of sections. The image data signals outputted from the multi-element photoelectric conversion means and sampled at a predetermined sampling period Ts are divided into nTs(n is an integer larger than l) An image data processing means for dividing the image data into n series of image data signals having a sampling period of nTs f via n series of sampling pulse signals having a period of t-ffi, provided on the entire image data transmitting side. An image data transmission method characterized by: