The People of the-State-of California appeal from a judgment of the" Municipal Court for the Central Judicial District, County of Sonoma, State of California, dismissing a complaint issued on a traffic citation for violation of section 22350 of the California- Vehicle Cоde.
This judgment was reversed by the Appellate Department of the Superior Court for Sonoma County. We accepted certification under rules 62 and 63 of the California Rules of Court.
The agreed statement on this appeal shows that the defendant was cited for violation of section 22350 of the California Vehicle Code. The complaint issued thereon charged that defendant exceeded the prima facie speed limit as estab *973 lished by- posted speed limit signs and that said violation was determined by and through the use of a radаr device.
, At the trial, tlie prosecuting attorney advised the court that this was a “radar” ease and that he intended to prove the instаllation; operation and accuracy of the radar machine through the testimony of the arresting officer. The court then inquired whether the People proposed to present an expert witness to establish the validity and accuracy of radar devices. The prosecuting attorney replied that they would not produce such a witness, whereupon the court, upon its own motion, dismissed the action, stating that the court would refuse to take judicial notice of the use, validity and accuracy of radar devices.
The sole issue presented is whether the trial court erred in refusing to take judicial notice of the use, validity and accuracy of radar deviсes.
In weighing whether the trial court committed error in refusing to take judicial notice of the “use, validity and accuracy of radar deviсes,” we interpret this to mean taking judicial notice of the principle of radar as an electronic device which scientifically and accurately measures speed of a moving object. This is altogether different from judicially noticing the accuracy and operating efficiency of the particular radar device used to measure the speed of the defendant’s vehicle in thе case before the court.
It is common and general knowledge that radar was developed in England in the late 1930's. In its most elementаry conception, it consists of a microwave transmitter sending out a directional signal which is reflected back to the transmission site by аn object in its path. The reflected signal is received back by an antenna into a receiving unit in the radar, and basically the time betwеen transmission and reception is measured electronically. Based upon the known speed of the signal, the time and speed factors provide the basis for an exact calculation of the distance between the radar and the reflecting object.
Radar has developed many uses since its introduction in the 1930’s, not the least of which is the highly simple, precise and accurate radar device for measuring the speed of a moving vehicle.
Although the legal issue presented to this court stands as a case of first impression in California, the precise question has been litigated in a number of other jurisdictions. While there is some conflict of authority on whether thе principle of radar *974 should he judicially noticed, the better-reasoned cases hold that it should.
In June 1955, the Supreme Court of New Jersey, in
State
v.
Dantonio, 18
N.J. 570, at page 578 [
In
People
v.
Magri
(1958)
Other jurisdictions have followed New York’s practical recognition that the scientific principle of radar can and should be judicially noticed. (See
City of East Cleveland
v.
Ferell
(1958)
California Evidence Code, section 451 (mandatory judicial *975 notice) provides in part: “Judicial notiсe shall be taken of: ... (f) Facts and propositions of generalized knowledge that are so universally known that they cannot reasonably be the subject of dispute. ”
We have concluded that the validity and accuracy of radar devices is a proposition оf such common and universal knowledge that it must he judicially noticed and there is no necessity to call an expert witness to establish this cоmmonly known and accepted proposition. As stated in
Varcoe
v.
Lee
(1919)
Under Evidence Code, section 451, judicial notice of the matters specified therein is mandatory, whether or not the court is requested to notice them. (California Evidence Code Manual (Cont.Ed.Bar 1966), Comment, p. 63.)
As indicated, this court’s holding is limited to the proposition that a trial court is required to take judicial notice of the use, validity and accuracy of radar devices as a scientific method of measuring speed.
The judgment dismissing the complaint is reversed, and the cause is remanded to the trial court for further proceedings in accordance with the views herein expressed.
Agee, J., and Taylor, J., concurred.
