CN118687546A - Ground landmarks to facilitate geometric correction of hyperspectral images - Google Patents

Abstract

The main problem solved by the present invention is how to ensure that ground marks can be identified at the same time when geometric correction is performed on two images of different bands at different time periods during hyperspectral aerial photography. The ground mark that is convenient for geometric correction of hyperspectral images is characterized by including a light source and a shell. The light source covers the spectral range of hyperspectral imaging, including ultraviolet light source, visible light, near-infrared light source, and medium and far-infrared light source. The number of each light source is at least two, and each light source is on the circumference of a circle, and the circles where the various light sources are located are cocentric. The shell fixes the relative positions between the light sources. The beneficial effect is that the ground mark can be imaged in almost all hyperspectral bands, and there is a unique center point regardless of the band used for imaging, thereby ensuring the accuracy of the position of the ground mark.

Description

Ground landmarks to facilitate geometric correction of hyperspectral images

Technical Field

The invention relates to the field of hyperspectral technology, in particular to ground markers for facilitating geometric correction of hyperspectral images.

Background Art

During aerial imaging, ground landmarks are obvious and clear positioning identification marks on the image. Currently, road intersections, river crossings, building boundaries, farmland boundaries, etc. are usually used. However, for hyperspectral aerial photography, there are usually hundreds of bands, and the wavelength range of each band is only a few nanometers. Since each band is imaged separately, only the light within the wavelength range can be imaged in the band. Therefore, the above-mentioned ground landmarks may not have clear images in many bands (for example, in a certain band of visible red light in the hyperspectral spectrum, only the red light within the band can be imaged, and the ground landmarks within the above-mentioned visible light wavelength range may not be clearly imaged). When geometric correction is performed on two images (or maps) of different time periods and different bands, the ground landmarks may be difficult to be identified at the same time, and it is difficult to match the positions of the aerial images and the ground landmarks.

Summary of the invention

The main problem solved by the present invention is how to ensure that ground signs can be recognized simultaneously when geometric correction is performed on two images of different bands at different time periods during hyperspectral aerial photography.

A ground marker for facilitating geometric correction of hyperspectral images is characterized in that it includes a light source and a shell. The light source covers the spectral range of hyperspectral imaging, including ultraviolet light source, visible light, near-infrared light source, and medium and far-infrared light source. The number of each light source is at least two, and each light source is on the circumference of a circle, and the circles where the various light sources are located are cocentric. The shell fixes the relative positions of the light sources. The upper surface of the shell is made of transparent material at the position above the light source. The transparent material can transmit the light emitted by the light source and can protect the light source. The upper surface of the shell is provided with light-absorbing material except for the position above the light source. The shell is provided with a mounting end, and the mounting end can fix the ground marker on the ground.

The beneficial effect is that the light source covers the spectral range of hyperspectral imaging, so the ground mark can be imaged in almost all hyperspectral bands. When geometric correction is performed on two images of different bands at different time periods (including image correction between hyperspectral and multispectral), it can be ensured that the ground mark can be recognized at the same time, so that the two images have a common ground mark, and geometric correction can be achieved by corresponding to the common ground mark. Moreover, when geometric correction is performed on images of different bands at the same time period of the same hyperspectral camera, since the images of different bands also have a common ground mark, it is also convenient to correct the geometric deformation of the image itself. In addition, the circles where various light sources are located are co-centered, so no matter what band is imaged, there is a unique center point to ensure the accuracy of the position of the ground mark. In addition, the number of each light source is at least two, and there is a certain distance or shape between each other, so that the ground mark has a certain size, can be imaged and easy to identify during hyperspectral aerial photography. If there is only one deuterium lamp, tungsten lamp, and silicon carbide rod, it may be regarded as stray light and difficult to be identified due to the small volume of the point light source, which will greatly reduce the efficiency of position matching. Of course, the more ground markers there are, the better. They are distributed on the ground at a certain density, so that the geometric correction effect of the aerial image is better and the actual geographic coordinates of each point on the ground are matched more accurately. Each light source is on the circumference of a circle, which means that the ultraviolet light source is on the circumference of a circle, the visible light and near-infrared light sources are on the circumference of a circle, and the mid- and far-infrared light sources are on the circumference of a circle. The circles can be the same circle or circles of different radii.

The light-absorbing material can absorb most of the light emitted by the light source, so that the upper surface of the shell hardly scatters light except for the location of the light source, and appears black to the human eye, and appears black when imaging in all bands of the hyperspectral spectrum, forming a sharp contrast with the location of the light source, which is more conducive to clear imaging. The light-absorbing material refers to a material that can absorb ultraviolet light, visible light, and infrared light, including black paint, carbon fiber, carbon nanotubes, etc.

The hyperspectral aerial photography described in the present invention refers to the aerial photography performed by mounting a hyperspectral camera on an aircraft or a satellite, which are respectively referred to as hyperspectral airborne aerial photography and hyperspectral satellite aerial photography. Since the satellite is far away from the ground, the resolution of the hyperspectral satellite aerial photography is usually lower than that of the hyperspectral airborne aerial photography. Therefore, when the marker is used for hyperspectral satellite aerial photography, its size should be appropriately increased so that it can be clearly imaged.

The ultraviolet light source is a deuterium lamp, the visible light and near-infrared light sources are tungsten lamps, and the mid-infrared and far-infrared light sources are silicon carbide rods.

The beneficial effect is that the deuterium lamp, tungsten lamp and silicon carbide rod can basically cover the spectral range of hyperspectral imaging, and the combination is simple and practical. The main function of the deuterium lamp is to serve as an ultraviolet light source. The wavelength range of the light emitted is generally 190~400nm, which is a continuous spectrum band. The working principle of the deuterium lamp mainly relies on plasma discharge, that is, the deuterium lamp is always kept in a stable deuterium element (D2 or heavy hydrogen) arc state. When powered on, the cathode plasma discharge produces electron emission, and the high-speed electrons collide and react with the atoms in the high-purity deuterium gas, thereby producing a continuous ultraviolet spectrum band with a wavelength range of 190~400nm. The wavelength range of the tungsten lamp mainly involves the visible spectrum region and the near-infrared region. Tungsten lamp is one of the more commonly used light sources in hyperspectral analysis. As the most commonly used visible light source, tungsten lamp is a light source with high brightness, high stability and long life. It can emit a continuous spectrum with a wavelength of 325~2500nm, so it can also be used as a near-infrared light source. When the silicon carbide rod is electrically heated, it radiates approximately like a black body in the wavelength range of 2000 to 20000nm, and is a medium and far infrared light source.

The deuterium lamp, tungsten lamp and silicon carbide rod are distributed on the circumference of the same circle. With the center of the circle as a reference, the deuterium lamp, tungsten lamp and silicon carbide rod are all symmetrically distributed about the center of the circle.

The beneficial effect is that the deuterium lamp, tungsten lamp and silicon carbide rod are each at a certain distance from each other (the maximum distance is the diameter of the circle), which is convenient for imaging and identification during hyperspectral aerial photography. At the same time, the center points of the deuterium lamp, tungsten lamp and silicon carbide rod are coincident, and there is a unique center point when imaging in any band, ensuring the uniqueness and accuracy of the ground mark position. The deuterium lamp, tungsten lamp and silicon carbide rod are each symmetrically distributed about the center of the circle, which means that the deuterium lamp is symmetrically distributed about the center of the circle, the tungsten lamp is symmetrically distributed about the center of the circle, and the silicon carbide rod is symmetrically distributed about the center of the circle.

Alternatively, the number of the deuterium lamp, the tungsten lamp, and the silicon carbide rod are all four, and the deuterium lamp, the tungsten lamp, and the silicon carbide rod are each evenly distributed on the circumference of a circle.

The beneficial effect is that the four deuterium lamps, tungsten lamps, and silicon carbide rods each form a cross and have a certain size, which is convenient for imaging and identification during hyperspectral aerial photography. At the same time, the center points of the deuterium lamps, tungsten lamps, and silicon carbide rods overlap, and there is a unique center point when imaging in any band, ensuring the uniqueness and accuracy of the ground mark position. The deuterium lamps, tungsten lamps, and silicon carbide rods are each evenly distributed on the circumference of a circle, which means that the deuterium lamps are evenly distributed on the circumference of a circle, the tungsten lamps are evenly distributed on the circumference of a circle, and the silicon carbide rods are evenly distributed on the circumference of a circle, wherein the circles are not the same circle.

When the ground sign is installed, with the center of the circle as the center, the four deuterium lamps, tungsten lamps and silicon carbide rods are respectively located in the southeast, northwest and northeast directions.

The beneficial effect is that the cross faces the southeast, northwest, and north directions, so that the ground mark has directionality, so the ground mark has direction reference and correction functions during aerial imaging. The four deuterium lamps, tungsten lamps, and silicon carbide rods are respectively located in the southeast, northwest, and north directions, which means that the four deuterium lamps are respectively located in the southeast, northwest, and north directions, the four tungsten lamps are respectively located in the southeast, northwest, and north directions, and the four silicon carbide rods are respectively located in the southeast, northwest, and north directions.

Alternatively, the number of the deuterium lamps, tungsten lamps, and silicon carbide rods are all even numbers, the deuterium lamps, tungsten lamps, and silicon carbide rods are distributed on the same straight line, and with the center of the circle as a reference, the deuterium lamps, tungsten lamps, and silicon carbide rods are each symmetrically distributed.

The beneficial effect is that the deuterium lamp, tungsten lamp and silicon carbide rod are all in a straight line and have a certain length, which is convenient for imaging and identification during hyperspectral aerial photography. At the same time, the midpoints of the deuterium lamp, tungsten lamp and silicon carbide rod are coincident, and there is a unique center point when imaging in any band, ensuring the uniqueness and accuracy of the ground mark position. The deuterium lamp, tungsten lamp and silicon carbide rod are all symmetrically distributed, which means that the deuterium lamp is symmetrically distributed, the tungsten lamp is symmetrically distributed, and the silicon carbide rod is symmetrically distributed.

When the ground sign is installed, the straight line faces the north-south direction or the east-west direction.

The beneficial effect is that the straight line is oriented in the north-south direction or the east-west direction, so that the ground mark has direction reference and correction functions during aerial imaging.

Alternatively, the number of the deuterium lamp, the tungsten lamp, and the silicon carbide rod are all 3, and the deuterium lamp, the tungsten lamp, and the silicon carbide rod are each evenly distributed on the circumference of the same circle.

The beneficial effect is that the four deuterium lamps, tungsten lamps, and silicon carbide rods each form an equilateral triangle and have a certain size, which is convenient for imaging and identification during hyperspectral aerial photography. At the same time, the center points of the deuterium lamps, tungsten lamps, and silicon carbide rods are coincident, and there is a unique center point when imaging in any band, ensuring the uniqueness and accuracy of the ground mark position. The deuterium lamps, tungsten lamps, and silicon carbide rods are each evenly distributed on the circumference of a circle, which means that the deuterium lamps are evenly distributed on the circumference of a circle, the tungsten lamps are evenly distributed on the circumference of a circle, and the silicon carbide rods are evenly distributed on the circumference of a circle, wherein the circles are the same circle.

The system also includes an optical filter, which is installed on the light source and can filter out the overlapping wavelength ranges of the three light sources.

The beneficial effect is that after filtering out the overlapping wavelength ranges of the three light sources, the wavelength ranges of the deuterium lamp, tungsten lamp, and silicon carbide rod have no intersection, so no matter what wavelength band is imaged, there is a unique equilateral triangle formed by the three light sources, which is convenient for clear imaging and identification during hyperspectral aerial photography. For example, the optical filter is installed on the tungsten lamp to reduce its wavelength range to 400~2000nm, so that the wavelength range of the deuterium lamp is 190~400nm, the wavelength of the tungsten lamp is 400~2000nm, and the wavelength range emitted by the silicon carbide rod after being powered on and heated is 2000~20000nm, and the three light sources have no intersection.

It also includes a power supply and a switch. The power supply, the switch and the light source form an electrical circuit. When night-light aerial photography is performed, the switch is turned on and the light source is lit.

The beneficial effect is that the light source is only turned on when night-light aerial photography is needed, which can save energy. The power supply can be a solar power supply, which uses daytime light to store energy, and the light can be turned on and off by remote control at any time.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic diagram of the overall structure of an embodiment;

Figure 2. Schematic diagram of the upper surface structure of the shell;

Figure 3 is a schematic diagram of the overall structure of an embodiment;

Figure 4 is a schematic diagram of the overall structure of an embodiment;

Figure 5. Schematic diagram of the overall structure of an embodiment.

In the figure: 1. deuterium lamp, 2. tungsten lamp, 3. silicon carbide rod, 4. shell, 41. transparent material, 42. light-absorbing material.

DETAILED DESCRIPTION

Example

As shown in Fig. 1 and Fig. 2, a ground marker for geometric correction of hyperspectral images is characterized in that it includes a light source and a shell. The light source covers the spectral range of hyperspectral imaging, including ultraviolet light source, visible light, near-infrared light source, and mid-infrared and far-infrared light sources. There are at least two of each type of light source, and each type of light source is on the circumference of a circle, and the circles where the various light sources are located are cocentric. The shell fixes the relative positions of the light sources. The upper surface of the shell is made of transparent material at the position above the light source. The transparent material can transmit the light emitted by the light source and can protect the light source. The upper surface of the shell is provided with light-absorbing material except for the position above the light source. The shell is provided with a mounting end, and the mounting end can fix the ground marker on the ground.

The ultraviolet light source is a deuterium lamp, the visible light and near-infrared light sources are tungsten lamps, and the mid-infrared and far-infrared light sources are silicon carbide rods.

The deuterium lamp, tungsten lamp and silicon carbide rod are distributed on the circumference of the same circle. With the center of the circle as a reference, the deuterium lamp, tungsten lamp and silicon carbide rod are all symmetrically distributed about the center of the circle.

It also includes a power supply and a switch. The power supply, the switch and the light source form an electrical circuit. When night-light aerial photography is performed, the switch is turned on and the light source is lit.

Example

As shown in FIG3 , a ground marker for geometric correction of a hyperspectral image is characterized in that it includes a light source and a shell. The light source covers the spectral range of hyperspectral imaging, including ultraviolet light source, visible light, near-infrared light source, and mid-infrared and far-infrared light sources. There are at least two of each type of light source, and each type of light source is on the circumference of a circle, and the circles where the various light sources are located are cocentric. The shell fixes the relative positions of the light sources. The upper surface of the shell is made of transparent material at the position above the light source. The transparent material can transmit the light emitted by the light source and can protect the light source. The upper surface of the shell is provided with light-absorbing material except for the position above the light source. The shell is provided with a mounting end, and the mounting end can fix the ground marker on the ground.

The ultraviolet light source is a deuterium lamp, the visible light and near-infrared light sources are tungsten lamps, and the mid-infrared and far-infrared light sources are silicon carbide rods.

The number of the deuterium lamp, the tungsten lamp and the silicon carbide rod are all four, and the deuterium lamp, the tungsten lamp and the silicon carbide rod are each evenly distributed on the circumference of a circle.

When the ground sign is installed, with the center of the circle as the center, the four deuterium lamps, tungsten lamps and silicon carbide rods are respectively located in the southeast, northwest and northeast directions.

It also includes a power supply and a switch. The power supply, the switch and the light source form an electrical circuit. When night-light aerial photography is performed, the switch is turned on and the light source is lit.

Example

As shown in FIG4 , a ground marker for geometric correction of a hyperspectral image is characterized in that it includes a light source and a shell. The light source covers the spectral range of hyperspectral imaging, including ultraviolet light source, visible light, near-infrared light source, and mid-infrared and far-infrared light sources. There are at least two of each type of light source, and each type of light source is on the circumference of a circle, and the circles where the various light sources are located are cocentric. The shell fixes the relative positions of the light sources. The upper surface of the shell is made of transparent material at the position above the light source. The transparent material can transmit the light emitted by the light source and can protect the light source. The upper surface of the shell is provided with light-absorbing material except for the position above the light source. The shell is provided with a mounting end, and the mounting end can fix the ground marker on the ground.

The ultraviolet light source is a deuterium lamp, the visible light and near-infrared light sources are tungsten lamps, and the mid-infrared and far-infrared light sources are silicon carbide rods.

The number of the deuterium lamps, tungsten lamps and silicon carbide rods are all even numbers, and the deuterium lamps, tungsten lamps and silicon carbide rods are distributed on the same straight line. With the center of the circle as a reference, the deuterium lamps, tungsten lamps and silicon carbide rods are each symmetrically distributed.

When the ground sign is installed, the straight line faces the north-south direction or the east-west direction.

It also includes a power supply and a switch. The power supply, the switch and the light source form an electrical circuit. When night-light aerial photography is performed, the switch is turned on and the light source is lit.

Example

As shown in FIG5 , a ground marker for geometric correction of a hyperspectral image is characterized in that it includes a light source and a shell. The light source covers the spectral range of hyperspectral imaging, including ultraviolet light source, visible light, near-infrared light source, and mid-infrared and far-infrared light sources. There are at least two of each type of light source, and each type of light source is on the circumference of a circle, and the circles where the various light sources are located are cocentric. The shell fixes the relative positions of the light sources. The upper surface of the shell is made of transparent material at the position above the light source. The transparent material can transmit the light emitted by the light source and can protect the light source. The upper surface of the shell is provided with light-absorbing material except for the position above the light source. The shell is provided with a mounting end, and the mounting end can fix the ground marker on the ground.

The ultraviolet light source is a deuterium lamp, the visible light and near-infrared light sources are tungsten lamps, and the mid-infrared and far-infrared light sources are silicon carbide rods.

The number of the deuterium lamp, the tungsten lamp and the silicon carbide rod are all three, and the deuterium lamp, the tungsten lamp and the silicon carbide rod are evenly distributed on the circumference of the same circle.

The system also includes an optical filter, which is installed on the light source and can filter out the overlapping wavelength ranges of the three light sources.

It also includes a power supply and a switch. The power supply, the switch and the light source form an electrical circuit. When night-light aerial photography is performed, the switch is turned on and the light source is lit.

Claims (10)

1. The utility model provides a ground sign convenient to hyperspectral image geometry corrects, its characterized in that, includes light source, casing, the light source covers hyperspectral imaging's spectral range, including ultraviolet light source, visible light, near infrared light source, well, three kinds of light sources of far infrared light source, and wherein the quantity of each kind of light source is two at least, and each kind of light source all is on the circumference of a circle, and the circle that various light sources are located is the same center, the casing is fixed relative position between the light source, the upper surface of casing adopts transparent material in the position of light source top, transparent material can see through the light that the light source sent and can protect the light source, the upper surface of casing all possesses light absorbing material except the position of light source top, be equipped with the installation end on the casing, the installation end can with ground sign is fixed subaerial.

2. The floor marking for facilitating geometric correction of hyperspectral images of claim 1, wherein the ultraviolet light source is a deuterium lamp, the visible light, near infrared light source is a tungsten lamp, and the mid and far infrared light sources are silicon carbide rods.

3. The ground sign for facilitating geometric correction of hyperspectral images according to claim 2, wherein the deuterium lamps, the tungsten lamps and the silicon carbide rods are distributed on the circumference of the same circle, and the deuterium lamps, the tungsten lamps and the silicon carbide rods are symmetrically distributed with respect to the circle center.

4. The ground sign for facilitating geometric correction of hyperspectral images according to claim 2, wherein the number of deuterium lamps, tungsten lamps and silicon carbide rods is four, and the deuterium lamps, tungsten lamps and silicon carbide rods are uniformly distributed on the circumference of a circle.

5. The ground marker for facilitating geometric correction of hyperspectral images according to claim 4, wherein when the ground marker is installed, the four deuterium lamps, tungsten lamps and silicon carbide rods are respectively positioned in the southeast and northwest directions by taking the circle center as the center.

6. The ground sign for facilitating geometric correction of hyperspectral images according to claim 2, wherein the number of deuterium lamps, tungsten lamps and silicon carbide rods is even, the deuterium lamps, tungsten lamps and silicon carbide rods are distributed on the same straight line, and the deuterium lamps, tungsten lamps and silicon carbide rods are distributed symmetrically leftwards and rightwards by taking the circle center as a reference.

7. The floor sign for facilitating geometric correction of hyperspectral images as claimed in claim 6 wherein the straight line is oriented in the north-south direction or in the east-west direction when the floor sign is installed.

8. The ground sign for facilitating geometric correction of hyperspectral images according to claim 2, wherein the number of deuterium lamps, tungsten lamps and silicon carbide rods is 3, and the deuterium lamps, tungsten lamps and silicon carbide rods are uniformly distributed on the circumference of the same circle.

9. The floor sign for facilitating geometric correction of hyperspectral images as recited in claim 8, further comprising an optical filter mounted to the light sources capable of filtering out overlapping wavelength ranges of the three light sources.

10. The ground sign for facilitating geometric correction of hyperspectral images according to claim 2, further comprising a power supply, a switch, and a light source forming an electrical circuit, wherein the switch is turned on and the light source is turned on during night-light aerial photographing.