JA, this is from a paper on UAV's, this part was a comparison of TLAM vs. F-117 in ODS:
Those rates match up pretty well with the canadian assessment of LGB in Kosovo.The claim is put forward that the F-117 was 10 times more accurate than the TOMAHAWK, or TLAM, and that the pilot in the F-117 is the reason because the two systems are similar. This is the crux of the argument? Of 432 targets with BDA reports, 357 total were matched to a BE-number and had campaign input data. This database was used by the GAO to draw several conclusions about the effectiveness of airpower in the Persian Gulf. This data set is the basis for much of this argument. The F-117 had 122 fully successful strike and 87 not fully successful for 58 percent. The TLAM was 18 and 16 respectively, for 53 percent. A fully successful mission did not require restrike to accomplish mission objectives. The F-117 originally was assessed to have had an 80 percent bomb hit rate. This has since been refined to a 55 to 80 percent hit rate and only 57 percent of the targets assigned on the first night were struck (31 hits on 57 DMPIs using 60 weapons (13 no drops)). The lower success rate resulted when the data was rescored using standardized methodology. For instance, originally 32 percent of hits were credited without supporting video. This was contrary to the unit’s "peacetime training policy and the policies of other LGB-capable aircraft in Desert Storm." (GAO, App III:5.2.2)
To UAV or Not To UAV: That is the Question; Here is One Answer
I will try to hunt down some better data on JDAM, only one I've seen is from 2000 at "better than 90%", but it was a small sample (~50) of F-18 sorties.
JDAM is being introduced to fleet activities through a phase-in concept. Early operational fielding occurred during Operation Southern Watch, and as of 15 September 2000, 51 GBU-31(V)2/B had been employed from carrier based F/A-18C/D aircraft with a mission success rate of greater than 90%..
http://www.globalsecurity.org/milita...ons/gbu-31.htm
Last edited by highsea; 25 Aug 10, at 01:20.
In your discussion was not mentioned probability of war with technologically advanced enemy, who can disrupt GPS signal. Looks like Boeing goes in a right directon, but what are current capabilities of USAF in this scenario? Is the inertial guidance of JDAM good enough?Originally Posted by highsea
Never fight a land war in Asia.
I don't know specifics Nus, but the new generation of GPS sats have dedicated mil channels that are separate from the civilian channels. Supposedly these are more resistant to jamming.
We do have some experience homing on GPS jammers, so anyone who tries that might not be too happy with the results.
I suppose the accuracy of the INS guidance would be dependent on the distance it went without an update.
So is INS guidance the same thing that is used on "wind corrected munitions"? Basically it knows the aircraft's GPS coordinates at launch, the target's GPS coordinates, and uses the position, orientation, and velocity of the bomb to delivery to target without actively updating its GPS position during the delivery?
Sounds like the Paveway IV and LJDAM will have similar capbilties. GPS guidance with the ability to laser designate for high precision/moving targets with INS backup.
^^^ yeah. All of the current crop of JDAM's integrate INS, and the new crop of dual mode LGB's. The WCMD uses INS only.
The various INS systems use a series of rate gyros to measure the position and orientation in 6 axes (X,Y,Z, Pitch, Roll, Yaw) to calcuate where the bomb (or missile or aircraft) needs to fly.
They're pretty accurate, but obviously the more updates you give them, the better.
Quick google search result:
GPS Jammer
An interesting page. Never thought it is so easy. Looks like this device can be installed on any mobile platform and cheap enough to be quickly replaced. Bombing this device might not worth the effort.Russian GPS jammer.
Display card text reads as:
Jamming Transmitter for GPS/GLONASS Satellite Navigation Receivers
Function - Disrupts correct measurement of geographic coordinates by satellite navigation receivers
Technical Characteristics
Operating Range - 150-200 km
Output Power - 4 W
Antenna Gain Factor - 3-5
Transmitter Weight (without power supply) - 8-10 kg
Power Consumption - <25 W
Electrical Requirements - +15V 1.5A; -6V 1.5A
Text for the left knob: Freq Dev (0-6 MHz)
Text for the right knob: FM Mod (44-270 Hz)
--------------------------------------------------------------------------------
271454Z AUG 97SUBJ: RUSSIAN AVIACONVERSIA PORTABLE GPS AND GLONASS JAMMER
SYSTEM (U)
SUMMARY:
(U) CONFEX - THE RUSSIAN FIRM AVIACONVERSIA MARKETED AND DISPLAYED ITS
PORTABLE GPS AND GLONASS JAMMER AT THE MOSCOW AIR SHOW '97, 19-24 AUG 97, IN
MOSCOW, RUSSIA. THE 4-WATT JAMMER JAMS CIVILIAN AND MILITARY FREQUENCIES OF
GPS AND GLONASS UP TO A RANGE OF 200 KM. PROTOTYPE AT THE SHOW - LOOKING FOR
BUYERS.
My guess is in next 5 years JDAM will be affected by GPS jammers as often as LGB is affected by bad weather.
Never fight a land war in Asia.
JDAM can be affected by jammers but it can be overcome if the attackers' planners compensate for that fact and create back up plans.
Weaponeering JDAMs vs LGBs usually comes down more to weather and target considerations than overall hit %.
GPS receivers back 10 years ago could tell when they were being jammed or spoofed. They disregard that signal update off the other signals they are receiving. JDAM switches to its secondary (INS) for targeting if it has a GPS problem.
For 1st gen GPS its a problem. I would say anything built past the late 90s its an annoyance. One that gets silenced quickly.
We also know how to take care of GPS jamers. They are easy to find. Its the GPS signal coming from the ground vice the ones originating from the sky.
The last 3 F-15s are leaving Tyndall tomorrow.
That leaves a squadron of F-22s and a squadron of F-4s remaining. The F-4s are a civilian contract service I believe.
It does look weird seeing those 2 planes sharing the flight line though. Now that they moved the F-4s from the boonies and put them in the old f-15 shelters.
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