Hello, this is Zoom Salon. It's been a while since I last greeted you. I had been preparing for a hike, but during the monsoon season, it seemed like there was rain forecasted every weekend, making it difficult to gather the Avengers scattered across the country in one place. Right now, I am at the entrance of the Beomeosa Temple to start our hike. This time, we have Avengers with incredible abilities joining us. Shall we call them? 

Frankly, I wish you all a joyful hike! Three, two, one, let's start! We are at Cheonwangbong, 32.5 km from here, at a point 50 meters above sea level. Currently, there are 25 visible satellites, and 16 of them are receiving good signals. Our current location is 35 degrees, 16 minutes, 10 seconds north, and 127 degrees, 30 minutes, 22 seconds east. Let's check the smartphone as well: 35 degrees, 16 minutes, 10 seconds north.

How can GPS satellites at 127 degrees, 30 minutes, and 21 seconds longitude find my location? If I am in a place without internet, will the GPS satellites still function properly? And does our country have GPS satellites? If so, how many are there? GPS, which stands for Global Positioning System, is a system that allows you to find your location anywhere on Earth. Light travels at about 300,000 kilometers per second, which is equivalent to circling the Earth seven and a half times in one second. When a satellite sends a radio signal, the time it takes for the signal to reach the receiver can be used to measure the distance. However, since there are many points at the same distance, it is not possible to determine the exact location with just one satellite. Therefore, additional signals from other satellites are needed to find overlapping points and accurately determine the location. In three-dimensional space, at least three satellites are required. Unlike the atomic clocks on satellites, the electronic clocks in receivers are less precise, so even a difference of 0.01 seconds can affect the accuracy.

Even with thousands of kilometers of distance error, one more satellite is needed to reduce the time error. To accurately determine my location, at least four satellites are required. Among the five Avengers, the most expensive one is this, the Garmin Epix Pro. This watch has a unique feature. Shall we turn off the lights? I think it might help in urgent situations. The steep section going up to Koje from Hwaeomsa is densely forested in the summer, covering the sky completely. So, I think there will be some signal interference. The distance test is from Hwaeomsa to Nogodan. The Suunto 9 Peak recorded the longest distance, while the path set with the Gilsaem app, which has a signal set at 10-meter intervals, recorded the shortest distance. Smartphones use the same GPS, so the reception intervals are set differently for testing. Oh, look at the color! It's a beautiful hydrangea. Now, at the Nogodan pass, we are at Samdobong.

I'm on my way, and the morning dew on the green leaves is just wonderful. Indeed, Jirisan is beautiful. The mountain range of Seoraksan is more grand and spectacular, but somehow, I feel that the charm of Jirisan is more appealing. The forest is truly lush. The term Hae-bap is a brand name of a specific company, but it is often used as a generic term. The same goes for GPS. The satellites that help us find our location are operated by various countries under different names. The first satellite that was created and provided as a service was the American GPS, which is why we tend to refer to all location-finding satellites collectively as GPS. In fact, the correct term is GNSS, which stands for Global Navigation Satellite System. GPS is the American satellite system, and it is not an international standard. Other countries, feeling uneasy about military uses, have also developed their own satellite systems, such as Russia's GLONASS, China's BeiDou, and the European Union's Galileo. These systems consist of more than 24 satellites that cover the entire globe.

GNSS, or Global Navigation Satellite System, is a hot topic. Japan and India operate their own regional navigation satellite systems, with about seven satellites each. What about our country? Unfortunately, we currently do not have a positioning system. We are in the process of developing a positioning system based on RNSS, or Regional Navigation Satellite System. 

Using web services like sports watches or GPS tests, I can check the current status of satellites in the sky from my location. Red indicates weak signals, yellow indicates fair signals, and green indicates good signals. Currently, there are 69 visible satellites, with 34 of them being usable. You can also see the number of satellites by country; for instance, China has a significant number of Beidou satellites. 

In terms of compatible devices, models like Coros Apex 2 Pro, Suunto Vertical, and Garmin Epix Pro can receive positioning signals from all types of satellites. They are equipped with dual bands, which can maximize GPS accuracy. However, increasing accuracy requires more processing power.

Battery consumption increases. The older model, the Suunto 9 Peak, only supports single-band and can selectively receive signals from some satellites. It's a bit disappointing that I couldn't test the newly released Galaxy 7 and Ultra, which come with dual-band support, but I will have to try them out next time. During this hike, I set all devices to GPS with maximum accuracy, and I am testing them with a fully charged battery. I have arrived at Hwagaejae. In the summer, the best hiking route is the valley trail towards Bansun Bamsagol. Still, for now, I will diligently walk the main trail. Ah, summer is indeed summer; it's hot and humid. Hiking with my own car feels like a battle against sleep. I can hardly sleep while driving, so there are times when drowsiness hits me hard. Right now, I am feeling very drowsy.

Are we there yet? The Yangha Cheon shelter is 17.6 km away. I have now reached about the third point, but there is a difference in the time on my watch and also a discrepancy with my smartphone's web. Why is that? The distance is measured by receiving signals from satellites, but various obstacles along the signal's path cause errors in the distance measurement. The most representative obstacle is the ionosphere. The first cause of distance error occurs when the satellite's orbit deviates slightly from the ideal path. Additionally, as the satellite signal passes through the atmosphere, it can be delayed or distorted, leading to errors of more than 30 meters in position. Other signal obstacles include high-rise buildings, tunnels, and vehicles, which can also create various factors that degrade the radio signal. There are satellites that help reduce the errors caused by the signal passing through these obstacles. In our country, we have the fifth most advanced system in the world.

We are operating under the name kbas, and I am quite proud of it. It is a satellite-based augmentation system (SBAS) that establishes reference stations across the country, which are less affected by radio interference. These stations receive the same GNSS signals and correct various errors. The corrected signals are then sent to SBAS satellites that move at a constant distance. By receiving the corrected signals along with the GNSS signals, the system reduces ionospheric errors to within 1 to 1.6 meters. The ionospheric errors caused by space can be addressed by the country, but there are also various obstacles around us that interfere with radio signals. Urban high-rise buildings, car windows, and dense forests or tunnels can disrupt signals, leading to unstable distance measurements. The system filters out these unstable signals and only accepts high-quality signals to reduce distance errors.

The method is dual-band technology. Recently, as the prices of the technology chips have stabilized, it seems that they are increasingly being installed in smartphones and watches. The radio signals emitted from satellites have frequencies L1, L2, and L5. When a receiver only receives the L1 signal, it is called single-band. In contrast, when it receives two signals simultaneously, such as L1 and L2 or L1 and L5, it is referred to as dual-frequency or dual-band. Single-band can experience increased location errors due to signal degradation when encountering obstacles. On the other hand, dual-band technology filters out bad signals and receives good signals, thereby reducing location errors. To test the performance of dual-band, I conducted tests in areas with minimal radio interference, such as floors and parks. Based on the road markings, I indicated the actual path walked with a white dotted line. It seems that the Coros product has a characteristic of slightly smoothing the path, similar to photo editing, while the Suunto product aligns the path more accurately.

It seems that the distance may increase slightly due to the shaking. The Garmin shows two lines as it rotates twice. The more it overlaps, the more accurate it becomes. The smartphone equipped with dual-band enhances web precision, and although it rotates once, the results are surprisingly good. The Coros I wear has also become slightly smoother, but in areas without signal interference, the difference between dual and single appears to be minimal. The Suunto 9 Peak is also shaking a bit. This time, the test was conducted in an urban area where signal interference seems to be severe. The Coros performs relatively well, but during the smoothing process, the central circle has disappeared. The Suunto shakes a bit but draws lines more accurately. Garmin also shows good results in poor conditions. It seems that the starting point on most smartphone web applications is somewhat unstable, but the single and...

When compared, the results are indeed surprising. It seems a single-band signal is somewhat difficult to use between urban buildings. Another way to reduce distance error is to receive signals more meticulously, such as 1 second for every 1 meter, rather than receiving them sparsely, like 10 seconds for every 10 meters. What difference does this make? If we compare the distances when receiving signals densely at 1-second or 1-meter intervals versus receiving them sparsely at 5-second or 5-meter intervals, we find that the measurements taken with sparse signals yield shorter distances. The difference in distance becomes even greater in areas with many curves compared to straight sections. From accurate GPS standards, it can be observed that receiving sparse signals results in significantly shorter distances than the actual distance. Conversely, under inaccurate GPS standards, receiving dense signals may lead to overestimating the actual distance.

전달하기 어려운 복잡한 내용을 쉽고 간결하게 전달하는 것이 정말 힘든 일입니다. 말이 나오다가 입에서 엉켜버리곤 해요. 그래서 중간에 멈춰서 정리하고 다시 말을 내뱉고 또 엉키고, 정말 쉽지가 않아요. 공조하기 위해 운동 좀 했어요. 저희는 자전거 타고 짝 연습을 했는데, 산 같은 곳, 예를 들어 한라산이나 대둔산에 가야 해요. 대둔산은 완주가 빨라서 좋고, 고기를 많이 먹을 수 있어요. 하지만 지금 1박 2일로 애들이 남아 있어서 못 먹어요. 빨리 1박 2일, 저는 2박 3일로 가야 하는데, 일정이 맞지 않네요. 테스트한 두 곳 중에서 주변이 확 튀는 곳은 전파 방해가 없기 때문에, 조에서는 싱글하면 차이가 났어요. 그러면 이 산은 전파 방해가 두 곳 사이에서 어느 정도인지 이번 산행의 테스트 목적이 될 것 같아요. 군산에서 왔지요.

Ah, whether it's one night or two nights, it's all about the 2 nights and 3 days. I'm feeling anxious because there's only 26% left. I need to charge it. Sports watches mainly do timekeeping and distance measurement, but smartphones can do a lot more. They handle messaging, calls, and GPS. Therefore, we can't just set the GPS accuracy to the highest level; we have to consider the battery situation as well. If we need to use GPS for hiking, setting the accuracy too high will drain the battery quickly, which can be burdensome. Since the phone is directly connected to survival in the mountains, we need to be careful. You all need to stay strong! The battery must be sufficiently secured. Especially in winter, the discharge rate is quite fast. The Coros Apex 2 Pro has encountered an error; there was a problem with the measurement. 27.39 km, 28.66, 27.88.

I want to eat a little bit. Thank you so much, really, really. What is it? Watermelon! Now I have to go to the volcano. We went to the market and slept, and now we will go to the market tomorrow. No, no, we are going today. Oh, it's the market today. 

The Dae Bong Hwajangdong is nice. Yeonhwa Bible. 

Since April 1st, after the Jujak Dongryong Dalmasan Jeongju, I haven't really hiked much. It seems like this is the first time I've done a hike over 20 kilometers since then. My body isn't perfect, but I think I remember it to some extent. 

Tongcheonmun. 

2.8 km. 

39%. This was almost completely drained just before descending. I think the battery performance has degraded a bit because it's an older model. Suunto Vertical 72%. Garmin Epix Pro 65%.

What is this? What is this again? Oh, what is this? 11.6, 11.6, 11.76, 1918, 1920, 1909. The humidity is extremely high during the summer. Yesterday, while hiking, I got a blister on my butt. So, I really didn't want to go hiking today, with a 99% reluctance. I set an alarm for two hours later, thinking I would go hiking if I woke up. However, I woke up five minutes early. During the hike, I was so sleepy that I lay down in a suitable spot on the trail and took short naps while hiking. Still, after finishing, I felt a sense of accomplishment. This is the distance of the Hwadae trail hike. The Suunto Nine Peak ran out of battery at the 38.5 km mark, so I couldn't measure it, but after correcting for the characteristics of the Suunto and the remaining distance, the hiking distance came out to be approximately 4.5 km, which is the longest.

It was predicted that in the case of smartphone web, when the precision was set to 1 meter intervals, the distance values were similar to those of watches. However, when the precision was reduced to 10 meters, the distance difference increased significantly, ranging from 3 to 4 kilometers. The distance tested this time was from the Daeungmun of Hwaeomsa Temple to the Iljumun Gate of Daeungsa Temple, and if we measure to the Daeungsa parking lot, it seems that it would increase by about 2 kilometers. The distance for the hiking route is similar to the previous day, but the difference in distance is partly influenced by the hiking speed. Even if one stops at a certain point during the hike, slight movements around the GPS can cause the measured distance to increase a bit. During the hiking route, I was so focused that the hiking time was reduced by about an hour, and overall, the hiking distance was slightly shorter. The methods for measuring altitude include GPS, altitude maps, and barometric altimeters.

There are three main methods used, and the Avengers watches with built-in barometers show stable ascent altitudes. The Coros Apex 2 Pro failed to measure the ascent at Hwadae, but the results were based on the descent altitude measured during a hike the following day. On the other hand, smartphone apps measure altitude quite inconsistently. When I reached the summit of Cheonwangbong and compared the altitudes, the smartphone apps showed significant discrepancies. The ascent altitude for the Daehwa trail was approximately 100 meters lower than that of Hwadae. The altitude at Hwadae would be the same as the ascent altitude. Looking at the watches tested in this comparison, they are the latest models, but for hiking, they are already sufficient, so there is no need to be overly sensitive in your selection. Watches offer many good features beyond GPS, so it would be best to choose one that fits your hiking style. For those who run trails quickly, weight is also a consideration.

For those who focus on long-term backpacking, it might be beneficial to pay more attention to battery performance. When you get lost in the mountains, you can find your location and path using satellite maps, and if you become isolated, you can request rescue using GPS coordinates. The sky can certainly help us. I will conclude this video here. Thank you.

[등산과GPS] 화대종주 거리가 다른 이유가 있다 ? 순토,가민,코로스,트랭글

[등산과GPS] 화대종주 거리가 다른 이유가 있다 ? 순토,가민,코로스,트랭글

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