It is highly misleading to use maximum range to make any declaration as to which system is superior. Keep in mind that radar detection rely on Line-of-Sight (LoS). That mean from sea level to a certain altitude, neither the Eyrie nor the Phalcon is able to attain their maximum radar detection range.
This is an example of a nomograph...
Figure 3-9 Radar Line-of-Sight Range Nomograph
Here is where an airborne radar system differs from a ground antenna: As altitude increases, at some point, the radar's main beam must begin to sort of angle downward to maintain a fix on the Earth, unless the goal is to detect incoming objects from space.
Here is a chart illustrating the relationship between LoS and altitude...
Radio Line of Sight
At 10ft the transmitter can 'see' to about 4nm. At 15,000ft it is about 150nm. At 43,000ft it is about 260nm. Airliners' cruising altitude is around 35,000ft max, giving an LoS of between 220-230nm if someone want to transmit to the aircraft. Operationally speaking, an AWACS is best at the same cruising altitude as airliners do.
Example...
"Why Saudi Arabia Needs The AWACS"
The "AWACS" can fly up to 40,000 feet altitude but its radar elevation angle is optimized for operations at 29,000 feet.
NATO AWACS - Frequently Asked Questions
Q8. What is the E-3A's operational altitude?
A8. The E-3A normally operates at 30,000 ft (9,150m), which allows for optimum radar performance.
Why around 30,000-something ft alt best for AWACS? Clutter horizon.
All radar systems have a clutter region or threshold. These are detectable but
UNWANTED signals such as cosmic background radiation, television, cellular communications, etc...etc...The Earth itself with uneven terrain, water and vegetation will produce unwanted radar reflections. The radar system will filter out these unwanted signals, anything else above the clutter region will be tagged as 'suspect'. Further, as the AWACS aircraft flies, changes in the Earth's topography, including bodies of water, will produce uneven clutter returns. Over a known area, we can program the system to remember the area's clutter threshold but it is best to have the system make on-the-fly adjustments. This is happening so fast in the background that it is tranparent to the users, as it should be. But as the transmitter gains altitude, if the main beam does not maintain radar contact with the Earth to establish this important clutter threshold, the system eventually will be looking at outer space and filter out the very low cosmic background radiation signals. Useless, unless the system is looking for the Space Shuttle or the ISS.
I said elsewhere here and I will repeat: That with radar, larger antenna is usually better. Power output is proportional to array dimension. Larger array mean a narrower main beam which equal to better target resolutions. But for an airborne transmitter, there is a limit to array dimensions before the radar antenna system itself become aerodynamically dangerous. That is why we have different AWACS configurations, from a rotodome to side mounted arrays, anything to increase power output to have greater detection distance.
Clutter horizon is properly defined as the furthest distance (point) on the Earth that a main beam can reach and still have sufficient radar echoes for the system to establish a clutter rejection threshold. Imagine sitting on the floor, touch the floor with one's hand, then walk the fingers away from one's body until arm's length. That point is called the 'clutter horizon'. Arm's length is antenna power output. Shorter arm will have shorter distance reached, hence shorter clutter horizon. So the reason why AWACS aircrafts are usually at between 30,000 to 40,000 ft altitude is because even though we want to be as high as possible, we are limited by current antenna engineering and by the need to establish Earth clutter horizon. This altitude range is good enough for us to see -- distance wise -- against targets at above or below the transmitter.
Moving on...
Just because a radar, ground or airborne, claim a longer detection range than its competitors, it does not mean the system itself is overall superior.
System design, manufacture and even usage can affect the performance parameters. For an AWACS platform, range accuracy is important. Range accuracy is the measure of a target as indicated versus absolute. A second important parameter is range resolution. This is crucial with multiple targets, especially if they are flying close together. Poor range resolution, or radar resolution cell, will display two (or more) targets as one, leading the operator to a potentially negative tactical position.
RADAR *PULSE *CHARACTERISTICS
RANGE RESOLUTION.A radars resolution is its ability to display multiple targets clearly and separately.
Longer pulses have poorer range resolution. Targets too close together lose definition and become blurred.
Longer pulses have poorer range resolution, but longer pulses have greater range because of more power, as indicated by the same source above...
Generally, longer pulses emitted from a radar return more power, thus increased target information and data reliability. Longer pulses have the disadvantage in that fine details within the return echo may be lost.
In today's modern militaries, preferences leans towards multi-role aircrafts, that mean from one moment I may face multiple bombers to the next moment those same bombers become fighters, battling their way out of the battlefield, land at home, refuel, rearm and come back to attack me again. My enemy is also my next door neighbor, not someone who must travel literally thousands of nm across sovereign airspaces that may or may not be hospitable to him. So which is better, greater range at the expense of ambiguous multiple target information, or less effective detection range but superior multiple target resolutions?
There are more important factors regarding potentially hostile targets. They are target detection, classification and identification. Target detection is self explanatory. Target classification is like saying 'big airplane' and 'small airplane'. Large aircrafts like the C-5 or the 747 airliner do not the same flight profile as fighter aircrafts. Their flight profile is that of a steady heading, altitude and speed, from one location point to the next. If I ignore a C-5 for a minute, odds are very good that despite the few miles he traveled, I would be able to locate and track him again. Target identification is more precise, that is when I can say 'C-5' instead of 'large transport', or 'F-16' instead of 'small aircraft'. Target classification is based upon profiles that can be common to many aircrafts. Target identification is based upon unique physical characteristics possess by one or very few. Target classification is like the generic 'mother' while target identification is
MY mother. How many fighters out there whose intake is of the same location, dimensions and shape as the F-16's intake? On the other hand, the intakes of the MIG-25 and F-15 are nearly identical with the F-14's intakes close enough to the others'. I cannot afford to ignore fighters.
CombatAircraft.com - Formations
Those are the standard formations for flights of small and rapidly maneuverable aircrafts. A radar system with poor range resolution, meaning unable to distinguish individual fighters from each other in a single resolution cell,
COULD mislead me into believing there is one or two large transports coming my way. As this 'transport' closes the distance, by the time my superior range radar managed to classify these aircrafts into armed fighter-bombers, not bomb laden F-15Es or runway cratering Tornados, it may be too late. The further from me that I can at least classify a target the more time I will have in formulating an appropriate response. The reason why AWACS sales brochures focuses so much on detection range is because it is the easiest figure to lure people into buying. Or into debates.
Clear as mud?
