방공체계(IADS) 스파이 풍선을 계기로 NORAD가 레이더의 필터 감도를 변경

[위종민]

이달 초 중국 스파이 풍선 격추 사건 뒤로 NORAD가 레이더 필터 감도를 변경해 미확인물체 탐지 빈도가 증가했다고 합니다. 

2월 12일 펜타곤의 멜리사 달튼 차관보가 언론 브리핑에서 NORAD의 레이더 감도를 늘려 탐지 물체가 늘어났다고 얘기했고, 글렌 밴허크 NORAD 사령관은 저속 물체를 걸러내는 필터를 조정해 저속물체 탐지능력을 강화했다고 설명했습니다. 

스파이 풍선 격추 이후로 2월 12일 (21일은 오기인 듯 합니다.)  휴런 호 상공에서 F-16이 AIM-9X를 이용 미확인 물체를 격추하는 등 8일 동안 4차례의 미확인 비행물체가 탐지됐다고 합니다. 

https://www.airforce-technology.com/news/norad-increases-radar-sensors/

NORAD expands sensory filters of aerial intrusion over North America

NORAD expands sensory filters of aerial intrusion over North America

NORAD increases its radar sensitivity to identify more aerial intrusions over North America.

John Hill

US Airforce radar, TPS-75. Credit: DVIDS.

Amid fears of Chinese intelligence-gathering following the suspected Chinese spy balloon incident earlier in the month, the North American Aerospace Defense Command (NORAD) has seemingly altered its detection parameters inside US and Canadian airspace, resulting in a trio of shootdown of unidentified objects.

The Chinese balloon incident led NORAD to “enhance their radar, which may at least partly explain the increase in objects that we’ve detected over the past week” stated Assistant Secretary of Defence for Homeland Security and Hemispheric Affairs Melissa Dalton stated in a Pentgon press briefing on the 12 February.

NORAD Commander General Glen VanHerck provided further detail on the change to NORAD’s radar system.

“Radars essentially filter out information based on speed. So, you can set various gates. We call them velocity gates that allow us to filter out low-speed clutter. We have adjusted some of those gates to give us better fidelity on seeing smaller objects. You can also filter out by altitude. And so, with some adjustments, we’ve been able to get a better categorisation of radar tracks now,” VanHerck said.

This change of sensory equipment, though cautious, leaves unanswered questions. Is the information being received from sensors just raw data from aerial clutter tracked at low speeds, or is there a serious adversarial threat in the skies?

General Charles Brown, Chief of Air Staff to the US Airforce stated on 13 February that “the adjusting of the radar sensitivities, which means we’re seeing more things that we would normally see but we don’t fully appreciate, understand exactly what we’re seeing. And so we try to do recovery efforts for some of the things that we’ve shot down, we’ll know more”.

While this expansive tracking policy does not entirely confront the problem of nefarious aerial presence in US airspace, it is only with further analysis of the objects in the process of recovery that will inform the nation’s next steps.

Threat proliferation?

North American skies continue to be encroached upon by mysterious aerial objects, with the latest incident on 21 February involving an aerial object flying at approximately 20,000ft altitude in US airspace above Lake Huron in the state of Michigan. The object was shot down by an F-16 fighter using an AIM-9X missile.

While the object did not pose a kinetic military threat, it was assessed to be a safety flight hazard and a threat due to its potential surveillance capabilities. The location to shoot down the object was specially chosen as the US military were able to avoid impact to people.

This aerial object follows a long string of flying objects over the North American continent in the past week; this is the fourth incident in eight days. It follows another object found over northern Canadian airspace only a day earlier, on the 11 February.

Meanwhile, the first object was a balloon operated by China that followed a path over key defence areas like Montana, where the US keep their siloed nuclear missiles.

The Chinese state insisted that their balloon was a civilian airship blown off course – over the entire Pacific Ocean and continental US – conducting meteorological research.

“Based on [the latest object’s] flight path and data we can reasonably connect this object to the radar signal picked up over Montana, which flew in proximity to sensitive DOD sites” the Pentagon stated on 12 February.

Although the surveillance balloon does represent a prelude to worsening tensions with China, the flying objects found more recently are shrouded in mystery. NORAD has responded to the aerial threat by unfiltering their sensory equipment that identifies these objects.

[백선호]

저속이면서 아주 높이 나는 것으로 저런 풍선 외에 또 뭐가 있을라나요? 새들은 아닐 것 같고...

[위종민]

높이 난다는 학 종류들도 1만 미터를 넘지 않으니 새는 아닐 테고, 라디오존데 등 풍선이나 성층권 비행선들밖엔 연상이 안 되네요.

[Minowski(김유철)]

왠지 작년에 개고생한 대만공군이 생각나서 좀 짠해지넉요.

[위종민]

슬슬 남의 얘기가 아닐 듯한 느낌..

[백선호]

https://apps.dtic.mil/sti/pdfs/ADA434352.pdf

[위종민]

Near-space platform이라면 성층권이나 중간권까지 올라가는 기구나 비행선 같은 걸까요?

[백선호]

65,000 ~ 325,000 feet 사이에 있는 것들이라네요.