EMALS & JPALS for the JSF

[spazsinbad]

As indicated on another thread: http://www.f-16.net/f-16_forum_viewtopic-t-12631.html (work backwards from last page to get to 'auto land' & SRVL for JSF) but repeated here is the 2005 first auto land by the VACC Harrier simulating what F-35B will do soon:
http://www.qinetiq.com/home/newsroom/ne ... first.html

Since the mid 1960s or thereabouts when an F-8 Crusader did a fully auto landing the USN has had that ability in some form in later jet aircraft (as a very broad generalisation). However this ability is seldom used in practice from what I have 'read' about this issue. From time to time it comes in handy as exemplified in a recent APPROACH story about 'fog in Hornet cockpit' requiring such an auto approach with pilot recommending that Hornet pilots practice these approaches more often (I'll leave details to others to explain).

'outlaw162' explains well. One minor correction about my own experience: Vampire was training aircraft with the A4G Skyhawk being flown from NAS Nowra & HMAS Melbourne with the Macchi MB326H replacing the Vampire/Sea Venom (Venom obsolete by 1969) as the 'advanced training' aircraft at Nowra. Having the TACAN instead of only radio beacon direction finder was 'revolutionary' but that was it; apart from better, more reliable IFR instruments. Precision approaches were via GCA/CCA with night carrier landings being done from a CCA (Carrier Controlled Approach) looking ahead at 1NM at 1,000 feet trying to see the ball in the bright light of mirror, eventually starting to get differentiation of meatball and datum lights from between 3/4 to 1/2 mile thankfully. Line up was not easy to see until then either so it was critical to have a good CCA operator for a good start.

All that is mentioned to convey what must be today and soon a much easier 'carrier landing' environment for the JSF/F-35B/C. Also remember the pilot will be able to 'see' through the aircraft to better be able to 'deck spot'. Just kidding - however overall with excellent aids as described the carrier landing experience in any weather within limits of ship movement will be outstanding. That's the plan anyway.

I would imagine that any 'auto' approach will have the pilot with hands on controls - just in case.

[spazsinbad]

USAF JPALS Accuracy Ashore from a Jan 2009 PDF:

Electronic Systems Center New Horizons Symposium

http://www.afceaboston.com/documents/ev ... 20ELSW.pdf (9Mb)

"Rapidly Deploy Adverse Weather, Adverse Terrain, Survivable, Maintainable, and Interoperable Precision Approach and Landing System (Land and Sea) That Supports the Warfighter When Ceiling and Visibility are Limiting Factors"
&
"JPALS Increment 2
- 200 ft/ ½ SM; Supports Auto-Land, Mobile/Fixed Local Area Differential GPS
- Customers: Air Force, Army, Navy & Marines"

[neptune]

JPALS is based on differential Global Positioning System (GPS) technology, and consists of modular avionics and ground/shipboard components to provide a range of landing minima and system configurations. Aircraft receive ranging and navigation data from the satellite constellation and differential ranging data or corrections from a ground/shipboard station via a data link.

..."At a 20-nm range from the carrier, the autoland level of data link operations kicks in." JPALS is a "UHF TACAN like" system; (NO RADAR).

Rockwell Collins is implementing the airborne UHF datalink for JPALS in the ARC-210 Gen5 radio. The ARC-210 Gen5 radio is a multi-band, multimode receiver-transmitter operating in the V/UHF frequency range, providing extended coverage from 30 to 941 MHz for military and public service radio bands. Rockwell Collins has delivered more than 30,000 ARC-210 radios used on 182 platforms since the start of the product line in 1990. The radio has evolved over successive generations with new capabilities added through software updates. Initial platforms expected to implement the Gen5 radio, a form-and-fit replacement for existing radios, are the MH-60 helicopter, V-22 tiltrotor and F/A-18, F-15 and F-16 fighters. The system tentatively would be integrated into the fleet in fiscal 2014.

http://www.ainonline.com/news/single-ne ... dio-30178/

[outlaw162]

The civilian version of this system (GBAS, previously called LAAS) is already in place at Newark with GLS approaches serving 5 runways.

Two of the runways have minimums at 200' with a 2400' RVR (same as CAT I ILS). The B737 NG Multi-Mode Receivers and Integrated Approach Navigation capability incorporated in the Flight Management System allow for auto-pilot coupled (or hand flown) approaches down to minimums. I would compare this to ILS, precise lateral & vertical guidance, not TACAN.

Auto-land capability & CAT III Ops are the next step on the civil side. That may be a more lengthy process as far as certification.

Military implementation of the JPALS system can probably bypass some of the 'passenger safety' oriented regulatory 'speed-bumps', especially for boat operations and probably even more so for un-manned aircraft. But right now the civil sector is running in first place, military closing fast on the outside, thanks to the F-35.

BTW, for the flight deck managed air traffic separation skeptics, evaluations of ADS-B based CDTI 'Merging & Spacing' and 'Interval Management' capability are currently in progress. It's not a matter of 'IF', but 'WHEN'.

(For Spaz: I believe the Sydney Kingsford-Smith airport has implemented or is the process of implementing a GBAS system also.)

OL

edit: Substituted 'flight deck managed air traffic' separation for 'onboard' separation. Onboard sounds like a boat thing. Although 'deck' does too. My apologies.)

[spazsinbad]

neptune, an interesting link about the radios. The article mentioned - at the end - has this to say about JPALS:

Paris 2011: Rockwell Collins delivers first software-defined ARC-210 radio By: Bill Carey | June 21, 2011

http://www.ainonline.com/news/single-ne ... dio-30178/

"...The company expects to deliver about 300 Gen5 radios this year, including 90 low-rate initial production (LRIP) models. Of those 90, 20 were delivered to PMA 209 and 70 to PMA 213, the naval air traffic management systems program office. PMA 213 is running the joint precision approach and landing system (JPALS) program. Through JPALS, which is comparable to the civilian GPS local area augmentation system, aircraft will receive differential GPS corrections from a shipboard station via datalink, providing U.S. Navy aircraft carriers with all-weather landing capability. Rockwell Collins is implementing the airborne UHF datalink for JPALS in the ARC-210 Gen5 radio.

In September 2008, Raytheon was awarded a $233 million contract for the JPALS system development and demonstration phase, heading a team including Rockwell Collins, Northrop Grumman and SAIC. Raytheon is performing the shipboard integration piece of JPALS.

Brunck said Rockwell Collins anticipates a contract from Navair for the airborne piece of JPALS. First software delivery would be in July 2012, allowing further development and testing of airborne and shipborne links. The system tentatively would be integrated into the fleet in fiscal 2014."

[spazsinbad]

More context - here is an illustration about PALS details/limits from the LSO Reference Manual 1999, lots of good text to go with it if anyone interested.

http://63.192.133.13/VMF-312/LSO.pdf (5.5Mb)

[outlaw162]

LSO Reference Manual 1999

The LSO pdf doc from 1999 (chapter 7) covers details/limits of the ILS beam style and CCA radar style approaches, not the differential GPS style approaches. The limits and capabilities of the GPS based approaches are still classified. PALS is just a generic acronym for precision approach capability.

The only existing operational differential GPS precision landing systems are at civilian airports right now. They are called GLS approaches. The only operational (not test or developmental) aircraft with the MMR's to use GBAS/LAAS for GLS are civil airliners. What may eventually be retro-fitted to the existing civil systems from the military systems under development will be some security oriented and anti-jam features.

Civil aviation goal is CAT III zero-zero auto-land, just as is the military goal for both land & sea based systems. Right now the lowest civil minimums are 200' ceiling and 2400' RVR.

http://www.hanscom.af.mil/news/story.asp?id=123246189

[spazsinbad]

outlaw I'm not suggesting that PALS is JPALS - ilustration/pointer to PDF - 1999 - merely for context about both systems. Other information about JPALS accuracy limits (that is public knowledge) has been posted elsewhere on this forum) [See graphic below first graphic for example]. Thanks for new link for JPALS getting back on track [Land-based precision approach system program resumes | Mar/10/2011] URL above.

This aspect from text at URL above is interesting for Carrier Approaches at night for example. Nowadays necessarily they are from long straightaways but with the F-35C DAS/HMDS night vision combo and JPALS a shorter, more 'carrier time efficient' night landing scenario might be envisioned: "...In the future, plans are for the LB JPALS to support not only straight-in approaches to the runway, but curved, segmented approaches or specialized approaches...."

ALSO from 'neptune's radio link above' it is suggested that not only will USN JPALS have satellite GPS but also shipboard GPS (derived from satellites or another independent source?). In this way I'll imagine the USN is independent in some ways if required. "...PMA 213, the naval air traffic management systems program office. PMA 213 is running the joint precision approach and landing system (JPALS) program. Through JPALS, which is comparable to the civilian GPS local area augmentation system, aircraft will receive differential GPS corrections from a shipboard station via datalink, providing U.S. Navy aircraft carriers with all-weather landing capability. Rockwell Collins is implementing the airborne UHF datalink for JPALS in the ARC-210 Gen5 radio...."
&
From the 'runway' graphic entry above in this thread: "JPALS Increment 2
- 200 ft/ ½ SM; Supports Auto-Land, Mobile/Fixed Local Area Differential GPS
- Customers: Air Force, Army, Navy & Marines"

"This graphic depicts the concept of operations for the Joint Precision Approach and Landing System, or JPALS...."

http://www.hanscom.af.mil/shared/media/ ... 10-002.jpg



FROM: http://www.f-16.net/f-16_forum_viewtopi ... rt-60.html
http://attach.high-g.net/attachments/jp ... nt_614.gif

[spazsinbad]

There is some very technical JPALS stuff on the web (so don't expect me to understand it all ) but I does me best. I like graphics much the same way I like PLAYBOY for the articles....

A Robust GPS/INS Kinematic Integrity Algorithm for Aircraft Landing
Alison Brown and Ben Mathews, NAVSYS Corporation

http://www.navsys.com/Papers/06-09-002.pdf (0.5Mb)

ABSTRACT
Next generation GPS receivers will take advantage of Spatial processing from a Controlled Reception Pattern Antenna (CRPA) and Ultra-Tightly-Coupled (UTC) and Tightly–Coupled GPS/inertial signal processing to improve their robustness to interference and their performance in a multipath environment. This introduces the potential for failure modes to be introduced into the GPS solution from the Spatial processor, GPS signals or Inertial Measurement Units (IMUs). For high integrity applications such as nonprecision approach or precision approach, the integrated GPS/Inertial receiver must be designed to perform fault detection and exclusion of any hazardously misleading information....

INTRODUCTION
The Joint Precision Approach and Landing System (JPALS) Shipboard Relative GPS concept (SRGPS) is illustrated in Figure 1. The goal of the SRGPS program is to provide a GPS-based system capable of automatically landing an aircraft on a moving carrier under all sea and weather conditions considered feasible for shipboard landings. The presently utilized Aircraft Carrier Landing System (ACLS) is a radar-based system which was developed more than 30 years ago and has a number of limitations that make the system inadequate to meet present and future ship-based automatic landing system requirements. The goal of SRGPS is to monitor and control up to 100 aircraft simultaneously throughout a range of 200 nautical miles from the landing site[1]. Integrity monitoring is especially important for the last 20 nm of an approach and accuracy requirements are 30 cm 3-D 95% of the time.

The SRGPS architecture provides a precision approach and landing system capability for shipboard operations equivalent to local differential GPS systems used ashore, such as the FAA's Local Area Augmentation System (LAAS). A relative navigation approach is used for SRGPS with the "reference station" installed on a ship moving through the water and pitching, rolling, and yawing around its center of motion. In addition, the ship's touchdown point may translate up/down (heave), side-to-side (sway), and fore and aft (surge). Since the shipboard landing environment is much more challenging than ashore, the SRGPS approach must use kinematic carrier phase tracking (KCPT) to achieve centimeter level positioning relative to the ship’s touchdown point.

Next generation GPS systems designed for JPALS and SRGPS operations are expected to have performance advantages over previous generation user equipment (UE). While these designs will meet the objective of high anti-jam (A/J) and high accuracy performance, they must also implement integrity monitoring to be able to use the KCPT solution to support precision approach and landing...."

& from this thread: http://www.f-16.net/index.php?name=PNph ... e&start=30

http://attach.high-g.net/attachments/ho ... ks_700.gif

[spazsinbad]

And on similar thread: http://www.f-16.net/index.php?name=PNph ... e&start=30

JPALS Program Update CAPT Drew Williams, US Navy NAVAIR PMA-213 15 APRIL 2010
http://www.afceaboston.com/documents/ev ... 20Williams).pdf (2.5Mb)

http://attach.high-g.net/attachments/jp ... nt_100.gif

[spazsinbad]

Graphic from: ‘Automated Carrier Landing of an Unmanned Combat Aerial Vehicle Using Dynamic Inversion’

http://www.dtic.mil/cgi-bin/GetTRDoc?Lo ... =ADA469901

But also repeated in JPALS graphic above - again here for clarification.

[spazsinbad]

JPALS: Not Just LAAS in Navy Uniform by William Reynish | October 1, 2002

http://www.aviationtoday.com/print/av/i ... 12893.html

"The seagoing Joint Precision Approach and Landing System for the U.S. Navy provides much more than GPS differential accuracy corrections. It uses data link to give pilots a plethora of data from a host of sources.

When the U.S. Department of Defense opted for the Joint Precision Approach and Landing System (JPALS) in the mid-90s, most observers understood that this would be the military’s version of the GPS-based Local Area Augmentation System (LAAS), which is being developed for the Federal Aviation Administration (FAA). And to a certain extent, it will be. When deliveries commence around 2010 to the Army, Air Force, Marine Corps and Navy, land-based JPALS installations will closely resemble the FAA system.

Extraordinary Environment
But the seagoing JPALS will be a horse (or a LAAS) of a different color. One of the biggest differences will be its data links. For, as development has evolved, carrier-based JPALS has become a generic term applied to a wider data link environment than just the automatic landing portion....

...In fact, the Navy’s seagoing JPALS will be the centerpiece of a dedicated, data link-based, communications, navigation and surveillance/air traffic management (CNS/ATM) system, which will be aboard each of its 12 carriers. The Navy needs such a capability to provide safety, airspace management and, of course, surveillance protection against adversaries, as the vessel moves away from the mainland and across oceans, often towards unfriendly territory.

In a way, it will be like picking up a complete FAA air route traffic control center (ARTCC) from the mainland, along with all its radars and infrastructure, and shoehorning it into an aircraft carrier. And since the carrier’s raison d’etre is to extend military air power in all weather, you could even say that the seagoing JPALS’ ultimate purpose is to thread the tip of an autolanding aircraft’s arrester hook through an imaginary 9-square foot (0.83-square meter) box centered precisely 14 feet (4.3 meters) above the pitching and rolling stern of a carrier in very low visibility, by day or night....

...At a 20-nm range from the carrier, the autoland level of data link operations kicks in. Uplinked data will include landing weather conditions, such as the all-important wind speed and direction over the carrier deck, plus the continuously updated GPS differential accuracy corrections similar to those required for a LAAS-like precision approach. The corrections will be similar but with much higher accuracy than those used in LAAS or the shore-based JPALS units.

Extreme Accuracy
To assure the exact positioning of the aircraft’s arrester hook within the very small area on the carrier deck, the Navy turned to the commercial survey industry’s real-time kinematic (RTK) GPS technique, which uses the carrier phase of the GPS signals to achieve accuracies within centimeters. The Navy requires horizontal and vertical accuracies of less than 15 cm (5.9 inches), with integrity assurance of no more than 1.1- meter (3.6-foot) error in 10 million landings.

Remember that imaginary 9-square foot box? The Navy has proved that accuracies of this type are possible in autolanding exercises with F/A-18s and other aircraft on carriers and land facilities, using a modified, prototype JPALS system in conjunction with RTK. The service also has demonstrated the system’s immunity to GPS jamming....

...But JPALS has the answer here, too. Real-time corrections for deck movement, derived from the carrier’s inertial navigation system, are continually uplinked to an aircraft, as it makes its final approach. The corrections are fed to the autoland system, which makes attitude adjustments all the way to touchdown–or, more precisely, to the point of placing the arrester hook exactly between the second and third arrester cables, four of which are stretched across the deck 40 feet (12.2 meters) apart. JPALS will bid farewell to the "bolter," that colorful expression used by naval aviators for an aircraft whose arrester hook misses the cables and is forced to make a missed approach. But in tomorrow’s Navy, bolters may simply be an undesirable impediment to 4D, high-speed traffic flows...."

[popcorn]

I find it amusing they use a F-111 in the illustration.

[spazsinbad]

The image has been distorted for some reason (not done by me). Here is a closeup.

[spazsinbad]

'Threading the needle' with JPALS accuracy: http://acast.grc.nasa.gov/wp-content/up ... allace.pdf