A mix of space and airborne assets is likely required for a future ground moving target indication (GMTI) replacement for the Northrop Grumman [NOC] E-8C Joint Surveillance Target Attack Radar System (Joint STARS) aircraft.
While the U.S. Air Force seeks to avoid fielding large, vulnerable intelligence, surveillance and reconnaissance (ISR) aircraft as the service retools for “Great Power Competition” to counter China, the ISR payloads of drones may be too small for GMTI, low Earth orbit (LEO) satellites face the challenge of persistent stare, and geosynchronous satellites have the burden of responding to rapid re-tasking.
“JSTARS had a very long dwell time, and it could have a very fast revisit time–often times less than a minute; colloquially, you could call it ‘sit and stare,’ if you wanted to,” said Steve Hall, the director of the source operations group at the National Geospatial-Intelligence Agency (NGA). “But operating from space is a different story…When we’re saying, ‘We’re gonna replace JSTARS,’ there are operational realities between what JSTARS was able to do in theater with the air supremacy, and what it’s like operating in space because the two are not necessarily one and the same.”
Hall was speaking as a participant on Is There a Market Case for Commercial GMTI?–a March 19 panel at the SATELLITE 2024 conference in Washington, D.C. Panelists seemed to agree that there is not a current market case for commercial GMTI, for example in the oil and gas industry, but that one may develop. Industry has invested about $1 billion in remote sensing in the last five years for some 70 launches to provide maritime surveillance and DoD site monitoring to gauge the economic prowess of potential adversaries.
The inaugural Chief of Space Operations, now retired Gen. John “Jay” Raymond, disclosed the space-based GMTI effort in May 2021, which Space Force has undertaken in collaboration with the National Reconnaissance Office (NRO).
Last April, NRO Director Chris Scolese expressed confidence in space-based GMTI technology and said that the agency would begin launching GMTI prototypes in the next eight to 12 months (Defense Daily, April 18, 2023).
“Kepler always wins in space–always remember that,” Eric Jensen, the CEO of ICEYE U.S., said during the March 19 panel. “There are two ways of getting persistence over a given patch of Earth. If you’re in low Earth orbit, you need many hundreds of assets. If you’re farther away, you need less assets. The truth today is that if you took all the satellites of our remote sensing, commercial companies together–be it for EO (electro-optical), hyperspectral, or radar–you still would not have enough persistence.”
Yet, commercial space companies may have a role to play in the future Space Force/NRO space-based GMTI, for example “tipping and cueing” NRO satellites for an in-depth look at a given area on the ground.
Scott Herman, the chief product officer for Maxar Technologies said that remote sensing satellites’ speed in LEO–about Mach 22–gives them only 30 to 60 seconds of dwell time over a target–roads or lines of communication choke points, for example.
“There’s not much persistence in that, but the observation that you get–whether from SAR, EO, or other phenomenology, you can often derive motion vectors from that–this object was moving; it was moving in this direction at 30 knots or 30 miles per hour ” he said. “That’s useful from an activity perspective. That may tell you that this garrison that’s been sitting quiet for a year–we’re seeing things moving or not just parked. There is value–that is a form of MTI. What it’s not is the constantly staring, persistent, wide area asset that tells you, ‘Here’s this convoy moving up this highway.'”