The leader asks you to go to your home for dinner, even if you use a question sentence, you can't really take it as a question-

If you don't answer, then this working relationship will not be easy to maintain in the future.

What's more, Chang Haonan subjectively really wants to visit.

Ding Gaoheng's wife is one of the main responsible persons for China's underwater launch vehicles, that is, submarine-launched ballistic missiles.

A well-known but very low-key old-timer.

Seeing Chang Haonan nodding almost without hesitation, Ding Gaoheng happily put on his hat and picked up the packed briefcase:

"Let's go, let's go with me in my car, and then let Xiao Zhu pick you up after eating......"

……

At the same time, Jinling, Dajiaochang Airport.

Xu Yang jumped from the co-pilot seat of a liberation truck, and together with several people in a car behind him, he carefully unloaded a cylindrical piece of equipment in the cargo box onto the tarmac.

Compared with the capital, which is still a little chilly in the early morning or evening, the climate along the Yangtze River has obviously entered the middle of spring.

However, for Xu Yang, a native of Beijing, the climate here is not easy to adapt.

She sniffed slightly, only to feel a little uncomfortable from the plane flying in the sky just now.

But at this critical time, she can't care so much.

"Guo Gong, you go to the back and unload the test trolley and push it here, and then check it one last time to make sure there are no faults!"

"Others, one group goes to the test area to arrange the measurement and control points, the second group goes to the end of the runway to prepare to recover the test equipment, and the third group debugs the jammer ......"

In the midst of the noise, Xu Yang picked up a loudspeaker from the car and gave instructions to the crowd in an orderly manner.

About half a month ago, she was in the laboratory and suddenly received a call directly from the director of the Commission of Science, Technology and Industry for National Defense.

The other party conveyed Chang Haonan's meaning, saying that the military GPS receiving module they had been waiting for had been obtained and was on the way to Jinling Electronics 14, hoping that she could go over as soon as possible and finish the GPS jamming equipment project.

So, Xu Yang flew from the capital to Jinling.

In fact, the main hardware part of the GPS jammer has been completed before the 14th Institute, and what Xu Yang needs to deal with this time is mainly to write the software part according to the new algorithm and test the performance of the final product.

According to Chang Haonan and Xu Yang's expectations, the main role of this jamming device should be to deal with GPS-guided munitions, such as cruise missiles or satellite-guided bombs such as JDAM.

But the testing process certainly can't come that way.

On the captured unmanned underwater vehicle, there are only two sets of GPS receiving modules, one of which has been installed in the jammer to translate and distribute the signal, and only one can be used to test the jamming effect.

Not to mention that Huaxia does not have ready-made satellite-guided weapons available at hand today, and even if they do, it is impossible to really throw this only remaining set of seedlings from the sky.

It's a one-shot deal.

In case the first test doesn't go well, there's no chance to start over.

What's more, Chang Haonan also wanted to maximize the use of the residual value after the end of the test process, and then build a second jammer......

Therefore, the jammed object in the final test scheme becomes a GPS-guided car, which can perform simple turning maneuvers and drive to the intended target.

However, this guidance is not autonomous driving.

The logic of the cart's action is the same as that of a bomb, and after detecting that the route is offset, it turns in another direction until it coincides with the set route, and does not avoid any obstacles in between.

Therefore, this test must be carried out in an extremely open area.

Pick and choose, only the airport can barely meet this condition.

So I made some contact with the Air Force and borrowed the Dajiaochang Airport in the evening, when the planes had already returned to the airport.

"XCMG, I have checked it, and no problems have been found in the hardware and software."

Guo Lin pushed a metal cart about half a person tall from a distance, and said as he walked:

"But before we start testing, I think it's better to have a controlled set of tests to see how it works undisturbed."

Xu Yang nodded decisively:

"Let's go."

Then, together with a few fellow engineers, he pushed the trolley to the set starting point of the test.

"XCMG, this GPS jamming pod, I feel that Mr. Chang is in a hurry?"

On the way, Guo Lin casually asked:

"In the past half a month, he has called me four times to ask about my progress, although he didn't say anything much each time, but it is said that it will not be so frequent."

"Four times?"

Xu Yang raised his eyebrows slightly:

"How come I didn't know once?"

Guo Lin wiped the sweat running down his forehead:

"Uh...... I'm always worried that you're stressed, so I always tell me not to tell you until the project goes into testing. ”

Hearing this answer, Xu Yang pouted slightly in a complicated state.

In her scientific research career, this is the first time that others have taken special care of her progress.

It had always been her slowing down to adapt to others.

"Okay......"

Xu Yang casually combed his hair that was blown by the wind:

"However, he did inadvertently tell me before that he hoped that this thing could be put into use before next spring, and said that if it is used properly, it can have the effect of four or two thousand pounds."

"Before next spring?"

Originally, Guo Lin just asked casually, but this sudden time point made him a little strange:

"Is there anything special about this time...... Or does Chang always have other plans? ”

"I don't know......"

While speaking, the trolley has been pushed to the beginning of the landing runway.

Wait a while, it will be "released" here and will be used to simulate the trajectory of a GPS-guided bomb on a flat surface.

"Path coordinates 1-10 are set on the runway, 11-14 are set along the taxiway, and 16-20 enter the tarmac ......"

After all, the maneuverability of the four-wheeled car is much better than that of a bomb that can only rely on wings, so in order to better reflect the jamming effect, the path setting is relatively complicated.

It's actually the process of landing an airplane on the runway and then sliding back to the tarmac along the taxiway on the right.

"Okay, the setup is complete, ready to release!"

With Xu Yang's order, the tester turned on the power of the battery.

Immediately after, the slightly rudimentary car staggered forward.

Xu Yang and Guo Lin followed all the way behind, observing its movements.

Because the accuracy of GPS in the 90s was still relatively limited, if you look closely, it is actually a bit of a picture.

However, in general, it is still moving along the preset route.

Ten minutes later, the two of them successfully arrived at the predetermined coordinate point, that is, the location of the convoy on the tarmac.

The deviation is about 2 meters, which also meets the accuracy standard of military precision capture code.

Of course, in actual use, because the speed of the guided weapon is much faster than this car, the computing power of the chip on the weapon cannot catch up with the laptop, and the accuracy of satellite positioning for elevation is very poor, so the hit accuracy is generally not up to this level.

Like a satellite-guided bomb, the general accuracy will be around 10-30 meters.

Of course, it is still far less than the killing range.

"Send the car back and get ready to start the jamming test!"

……

On the tarmac, the test team operating the jammer had moved the equipment to a position close to the runway and aimed the transmitting antenna on the side of the cylinder into the air.

Because the receiving antennas of many GPS-guided weapons have directional capabilities, interference signals sent directly from the ground are likely to be filtered out and need to be refracted through the ionosphere to simulate satellite signals sent from space.

In order to achieve this requirement, the rated power of the entire jammer working state is very large, and the circuit design is also very ingenious.

It was still done by Chang Haonan himself.

"We set up the jamming method, take this runway as the axis, mirror all the GPS signals received in the range, and then resend them......"

"Set an exemption threshold to prevent the false signals after processing from being too biased and detected by the inertial navigation system......"

“……”

Xu Yang said as he set the jamming mode on the computer.

Of course, once the device is finalized, there will be several preset jamming algorithms to choose from.

After checking his settings for the last time, Xu Yang stood up and took the walkie-talkie from Guo Lin's hand.

"Attention all, attention to all, report readiness!."

After a brief silence, the intercom came with reports from the teams that were ready.

"Four sets, test subjects can be released."

After Xu Yang finished speaking, he put down the walkie-talkie, picked up the telescope handed over by the person next to him, and looked at the far end of the runway.

The car swayed forward while drawing a dragon.

It doesn't look any different from last time.

"One group of measurement and control, the data is normal."

The first report came over the intercom.

Because the interference is set to be symmetrical along the runway, it doesn't make a difference when you first drive in a straight line.

Soon, the car came to the entrance of the taxiway.

Depending on the course setting, its front wheels were deflected to the right.

Everyone's hearts instantly tensed.

But soon, the new navigation signal told it that it was going in the wrong direction.

So, the front wheels of the trolley turned around and turned to the "correct" left side.

That is, it is the opposite of the previous route.

"The second group of measurement and control, the target route has deviated."

"Measurement and control group three, the target is driving along the taxi path on the left......"

"Measurement and control group four, the target enters the left apron area ......"

“……”

In Xu Yang's telescope, it can also be seen that the car is firmly parked on the other side of the tarmac almost completely symmetrical to them.

"Damn, that's amazing......"

Guo Lin, who was also holding a telescope, muttered to himself:

"Doesn't that mean that the satellite positioning system is ...... Completely useless? ”

"Not really."

Xu Yang put the telescope aside and came to the computer next to him to check the operation log of the jammer:

"The range of a set of this thing is only two to three kilometers in diameter, and in order to ensure the interference power, the volume and weight are very large, and it is basically impossible to achieve full coverage of the battlefield."

"Moreover, the other side can also introduce more composite guidance on weapons or ammunition, especially the terminal guidance mode, to deal with our interference."

"In short, there is absolutely no equipment that can solve all problems, and the idea of underestimating the enemy must not be ......"

Although he said that, Xu Yang's face still showed a little joyful expression.

Obviously, the logging is doing pretty well.

So she changed her words:

"However, for some targets or areas that need to be protected, it is sufficient."

(End of chapter)