What does RVR mean when refering to visibility for aircraft?

Question

I was watching an episode of "mayday" and they mentioned RVR, but i never fully understood the term

Answer 1

The number of feet a pilot would be able to see during takeoff or landing as measured by a transmissometer at different locations on the runway.

Here is the definition as taken from the Pilot/Controller Glossary in the Aeronautical Information Manual:

Runway Visual Range (RVR). An instrumentally derived value, based on standard calibrations, that represents the horizontal distance a pilot will see down the runway from the approach end. It is based on the sighting of either high intensity runway lights or on the visual contrast of other targets whichever yields the greater visual range. RVR, in contrast to prevailing or runway visibility, is based on what a pilot in a moving aircraft should see looking down the runway. RVR is horizontal visual range, not slant visual range. It is based on measurement of a transmissometer made near the touchdown point of the instrument runway and is reported in hundreds of feet. RVR is used in lieu of RVV (Runway Visiblity Value) and /or prevailing visibilty in determining minimums for a particular runway.

RVR values are measured by transmissometers mounted on 14-foot towers along the runway and can include readings for TDZ (TouchDown Zone), Mid, and Rollout RVRs.

The back of Taxi charts will show how much RVR is required for takeoff. For example: A two engine turbojet at KLAX would need at least 600 RVR for takeoff, however, at least 2 of the 3 RVR values are required if Centerline Lighting & Runway Centerline Markings any RVR out.

On the Approach Charts RVR values are given for landing. For example: Using ILS Rwy 25L at KLAX, a Straight-in landing is authorized with a full ILS available to an RVR as low as 1800 RVR or 1/2 mile visibility.

Answer 2

Runway Visual Range

Runways with RVR capability have three sensors mounted along the side of the runway: one at each end and one in the middle. They use an optical (not IR) lens to measure the visibility at that point and transmit it to a readout in the tower. Takeoff and landing minima are based upon the RVR.

The advantage of this system is that it is more accurate and reports the actual visibility on the runway, not the prevailing visibility that is reported by an observer in the tower.

Answer 3

RVR is Runway Visibility Range. It consists or sensors (infrared I think) positioned at various points along the edge of the runway to measure the actual visibility on the runway (as opposed to the tower where prevailing visibility is measured). RVR figures are given in feet: RVR2600 equals 1/2 mile visibility and RVR1200 equals 1/4 mile vis.

Approach (especially CAT II and III) and takeoff minimums use RVR.

In Canada, we have approach ban, so at airports with an RVR that is showing below minimums, we can't even attempt the approach.

Answer 4

RVR,
in contrast to prevailing or runway visibility, is based on what a pilot in a moving aircraft

Answer 5

Rvr Aviation

Answer 6

how do i know the minimum rvr value needed by my aircraft?

Answer 7

as calnickle said , Ruway Visibility Range is true , it's table is here :
Cat D.H* R.V.R
1 200Ft 800meter
2 100Ft 400m
3(a) - 200m (see to land)
3(b) - 30m (see to taxi)
3(c) - zero (auto land)
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D.H stands for decision height
(table is according to the roman numral division)