What are the difficulties of the Yuanyuan 3 series of satellites as surveying and mapping satellites

At 11:13 on July 25, the 03 satellite of the resource 3 was successfully launched at the Taiyuan Satellite Launch Center, which will form a three-dimensional surveying and mapping satellite constellation with other surveying and mapping satellites such as the resource 3 satellite. The development of surveying and mapping satellites is difficult, and the main points are as follows.

Start from scratchAll the parameters of China's resource-3 satellite are designed from scratchIn the beginning, some data will be purchased from abroad, but they want to develop their own satellitesIt was necessary to use its own data parameters, so after four years of experiments, the technical support and materials required for the manufacture of the satellite were determined, and the project was finally established and the development began. The first problem to be solved is hardware, and China already basically has the ability to launch satellitesHowever, the photographic equipment of surveying and mapping satellites must be redeveloped in China, and surveying and mapping satellites can measure elevation, which ordinary rocker equipment cannot do at allSo it took three years for my country to go through countless experimentsFinally, it is a camera that does not distort in an environment with large temperature changes, has a good dynamic range, and has a very accurate image conversion rateHowever, this is also the first step in China's development of surveying and mapping satellites.

The most difficult thing to accurately locate a mapping satellite is how to reduce the error between the shooting area and the fieldSatellites need to obtain image data perfectly, and at the same time convert the image data into coordinates and send them backRecently, we also had an internship with SUPMAP, which is the use of American GPS to pinpoint a certain location on the earth, and it is difficult for us to even learn this software, let alone redevelop this software and make it more accurate. At the same time, surveying and mapping satellites need a 3D stereo map to measure the elevation, especially in some mountains and forestsIt took scientists even a year to solve this problem.

It's really hard to study mapping satellites, thanks to the continuous efforts of scientistsIt is hoped that scientists will be able to rock sunrise more powerful satellites in the future to enhance China's comprehensive scientific and technological strength.

As a surveying and mapping satellite, the Yuanyuan-3 series of satellites mainly has the following difficulties: 1. High surveying and mapping accuracy, mainly used for 1:50,000 scale stereoscopic mapping and digital image production; Second, it is necessary to collect high-resolution stereoscopic images.

How difficult is it for the resource-3 series of satellites to be surveying and mapping satellites, all the parameter design is from scratch, and it is very difficult to start from scratch, without any experience, all relying on independent research and development!

The first is that there are no data parameters for reference, which requires us to re-establish a set of data parameters of our own, which takes four years. The second is that the existing photographic equipment could not meet the demand, and after three years, the suitable equipment was finally developed. The third is that it is more difficult to measure the highlands and forests.

The main difficulty of the Yuanyuan-3 surveying and mapping satellite is that the plane positioning accuracy has been improved from 100 meters to better than 10 meters, which is the first time that China has applied this technology to a surveying and mapping satellite.

Satellite orbit parameters:

Satellite resolution parameters:

The Resource-3 Surveying and Mapping Satellite, referred to as ZY3, is China's first civilian high-resolution optical transmission mapping satellite, the satellite was launched on January 9, 2012, it is equipped with four optical cameras, including a ground resolution front-facing panchromatic TDI CCD camera, two ground-resolution front-facing and rear-facing panchromatic TDI CCD cameras, and a ground-resolution front-facing multispectral camera, the data are mainly used for topographic mapping, elevation modeling and resource survey. With a 5-year service life, the satellite can obtain stereoscopic panchromatic images, multispectral images and auxiliary data for a long time, continuously and stably, and can achieve seamless image coverage for areas within 84 degrees north and south latitudes of the earth.

China Resources 2 is a transmission remote sensing satellite. China Resources 2, developed by the China Academy of Space Technology under the China Aerospace Science and Technology Corporation, is mainly used in the fields of land and resources exploration, environmental monitoring and protection, urban planning, crop yield estimation, disaster prevention and mitigation, and space science experiments.

Sputnik: An unmanned spacecraft orbiting the Earth in space orbit. Artificial satellites basically orbit the earth in accordance with the laws of celestial mechanics, but because they are affected by the non-spherical earth's gravitational field, atmospheric drag, solar gravity, moon gravity and light pressure in different orbits, the actual motion situation is very complicated.

Artificial satellites are the most numerous, most versatile, and fastest-growing spacecraft launched. The number of satellites launched by the world accounts for more than 90% of the total number of spacecraft launched.

There are two types of resource satellites: one is land resource satellites, and the other is marine resource satellites. Resource satellites generally operate in sun-synchronous orbits, which can make the orbital plane of the satellite rotate 1 degree per day in the direction of the earth's rotation, which is basically equal to the distance of about 1 degree per day when the earth revolves around the rising sun.

In this way, the satellite can not only observe any location on the earth, but also enable the satellite to fly to a certain area at the same time every day to achieve regular survey.

Satellite orbit (nominal).

Orbital form: Sun-synchronous circular orbit.

Altitude: km.

Inclination: Regression period: 59 days.

Revisit period: 5 days.

Descending to the Junction Point: 10:30am

Satellite weight. Approx. 2650kg

Satellite lifetime. The working life in orbit is 5 years.

Ground cell resolution.

Front-view, rear-view camera:

Orthopedic Camera: Multispectral Camera:

Coverage Width: Front, Rear Camera: 52km

Front-facing camera: 50km

Multispectral camera: 52km

Image data compression ratio.

Panchromatic image: 2:1 4:1 optional.

Multispectral images: Lossless compression.

Number of data transmission channels: 2 channels.

Satellite payloads. The ZY-3 satellite is equipped with four cameras using the adaptively improved ZY-2 satellite platform

1) 1 orthogonal panchromatic TDI CCD camera with a terrestrial resolution better than that of meters;

2) 2 front-view and rear-view panchromatic TDI CCD cameras with a ground resolution better than that of meters;

3) 1 orthometric multispectral camera with a ground resolution better than that of meters.

Resource satellites are satellites that survey and study the earth's natural resources. It can "see through" the strata, discover underground treasures, historical monuments, and stratigraphic structures that people cannot see with the naked eye, survey crops, forests, oceans, air and other resources, predict and identify the harvest of crops, and investigate and forecast various serious natural disasters.

The ZY-3 satellite is China's first independent civil high-resolution stereo mapping satellite, through stereoscopic observation, it can measure 150,000 scale topographic maps, providing services for land resources, agriculture, forestry and other fields, and the ZY-3 satellite will fill the gap in the field of stereo mapping in China, at 11:17 on January 9, 2012, the ZY-3 satellite was successfully launched by the "Long March-4B" carrier rocket at the Taiyuan Satellite Launch Center. On January 11, the first batch of high-precision stereo images and high-resolution multispectral images were successfully transmitted, covering Heilongjiang, Jilin, Liaoning, Shandong, Jiangsu, Zhejiang, Fujian and other regions, with a total of about 210,000 square kilometers. On April 20, 2012, the in-orbit test of the satellite was completed.

The launch of the Luxembourg satellite is China's first space launch in 2012 and the 156th launch of the Long March series of carrier rockets. The satellite can achieve seamless image coverage of the area within 84 degrees north and south latitude of the earth, with a regression period of 59 days and a revisit period of 5 days. The design working life of the satellite is 4 years.