OPINION
BRYNER, Chief Judge.Charley R. Wamser was convicted of fishing commercially without required number *164plates on his vessel and of fishing in closed waters. On appeal, Wamser challenges only his conviction for fishing in closed waters. Wamser raises a number of interrelated issues. We affirm.
Wamser⅛ principal argument is that the trial court improperly applied Alaska Rule of Evidence (A.R.E.) 201 by taking judicial notice of the basic principles underlying use of the Loran C navigational system. Prior to his trial, Wamser received a letter indicating that Superior Court Judge Victor D. Carlson intended to take judicial notice of certain basic facts relating to Loran C navigation. Specifically, Judge Carlson indicated his intent to rely on a memorandum of judicial notice entered by Superior Court Judge J. Justin Ripley in four unrelated cases, which also involved charges of unlawful commercial fishing in the Bristol Bay area. In the prior cases, Judge Ripley considered expert testimony about the scientific principles underlying the Loran C system of navigation and the use of that system in the Bristol Bay area. Based on the testimony, Judge Ripley concluded that it was appropriate to take judicial notice of the general validity of the scientific principles underlying Loran C navigation and of the reliability and accuracy of the system, assuming all equipment was functioning properly.1
Prior to his trial, Wamser filed a motion to prevent Judge Carlson from taking judicial notice of any facts relating to Loran C navigation. Wamser also moved to suppress all evidence based on use of the Loran C in his case. After hearing argument, Judge Carlson ruled that he would take judicial notice of the scientific principles involved in the Loran C system. Judge Carlson also denied Wamser ⅛ motion to suppress. Wamser now maintains that the use of judicial notice in his case was inappropriate. We disagree.
Based upon our review of the expert testimony originally heard by Judge Ripley, we conclude that the basic validity and general acceptance of the scientific principles underlying the Loran C navigational system are facts that are “capable of accurate and ready determination by resort to sources whose accuracy cannot reasonably be disputed.” A.R.E. 201(b)(2).
Here, Wamser was provided ample advance notice of Judge Carlson's intent to take judicial notice and of the evidentiary base upon which the judge intended to rely. See Concerned Citizens v. Kenai Peninsula Borough, 527 P.2d 447, 451 (Alaska 1974). Wamser was also afforded a hearing as to the propriety of taking judicial notice in his case. He failed to establish, either by evidence or offer of proof, that the facts Judge Carlson intended to take judicial notice of were subject to reasonable dispute or incapable of being readily ascertained by resort to sources whose accuracy could not reasonably be disputed.
We are convinced that Judge Carlson’s use of judicial notice in this case was not unduly broad and did not improperly restrict Wamser’s rights to full and effective confrontation on cross-examination. Judge Carlson made it clear that he would take judicial notice of the scientific principles underlying Loran C navigation only to a limited extent. The judge specifically indicated that the state would be required to establish, as a foundational requirement, that its witness was reasonably qualified to operate a standard Loran C receiver and that the receiver actually used in the case was functioning properly at the time of the offense. Judge Carlson also indicated that Wamser would be entitled to challenge the *165accuracy of any Loran C reading actually obtained in his case.
At trial, fish and game officer Joseph W. Campbell was the only witness to testify for the state. Officer Campbell stated that, on June 10, 1982, while he was patrolling in closed waters just south of the King Salmon line, he spotted Wamser’s boat with its nets in the water. By looking at a bell buoy and beach markers, Officer Campbell determined that Wamser’s boat was in closed waters, about one-half mile south of the King Salmon line. Campbell testified that his visual observation was confirmed by his Loran C reading. Campbell testified about his experience operating Loran C receivers and about various factors indicating the accuracy of the Loran C reading that he received for Wamser’s vessel.
Wamser strenuously argues that Judge Carlson restricted the scope of cross-examination concerning Officer Campbell’s training and the accuracy of the Loran C reading he actually obtained. The record does not support Wamser’s claim. Judge Carlson gave Wamser ample latitude to cross-examine Officer Campbell as to his experience and qualifications in operating a Loran C receiver. The judge also allowed Wamser to question Officer Campbell about the accuracy of the Loran C receiver on board his vessel and the accuracy of the Loran C reading that he obtained at the time of the offense. Judge Carlson sustained objections to only two of Wamser’s questions dealing specifically with Loran C navigation. In our view, both questions were properly disallowed.2 Furthermore, the record fails to support Wamser’s contention that Judge Carlson improperly instructed the jury with respect to judicial notice. Judge Carlson did not make any statements to the jury concerning judicial notice, either while Officer Campbell was testifying or in his final jury instructions.
After considering the record as a whole, we conclude that Judge Carlson properly took judicial notice of the validity of the scientific principles underlying Loran C navigation and of the theoretical accuracy of the Loran C system. We further conclude that Wamser was given ample opportunity to challenge the accuracy of Officer Campbell’s testimony concerning the Loran C reading he obtained for Wamser’s vessel. We therefore reject Wamser’s separate claim that his constitutional rights to confrontation and cross-examination were violated.
Wamser has additionally argued that Judge Carlson erred in refusing to suppress the Loran C reading for his vessel. *166Wamser claims that the Loran C reading as displayed in digital form on the Loran C receiver, was required to be preserved under the best evidence rule. A.R.E. 1002. Wamser further alleges that failure to preserve the original digital display, either photographically or by means of a mechanical printout, deprived him of due process. See Brady v. Maryland, 373 U.S. 83, 83 S.Ct. 1194, 10 L.Ed.2d 215 (1963); Lauderdale v. State, 548 P.2d 376 (Alaska 1976). Wamser acknowledges that Officer Campbell’s Loran C receiver was not equipped with any mechanism capable of providing a printout. He nonetheless contends that it should have been so equipped. We find this argument to be frivolous and hold that neither A.R.E. 1002 nor due process mandated exclusion of the Loran C reading.
The conviction is AFFIRMED.
. Judge Ripley’s memorandum of judicial notice provided, in relevant part:
IT IS JUDICIALLY NOTICED AND ESTABLISHED IN THESE PROCEEDINGS THAT:
1. The physical, electronic and cartographic principles underlying the transmission, reception and plotting of Loran C information are well established and verified by scientific inquiry so that their accuracy is not questioned; and
2. If the Loran C receiver operator is familiar with the function of his equipment, if his equipment is functioning normally and in accordance with its instruction manual, the location information received is accurate.
. First, Wamser attempted to question Officer Campbell about his knowledge of a shutdown by coast guard officials of all Alaska Loran C transmitting stations. Wamser was aware that the shutdown occurred five days after this offense and was for routine maintenance purposes. We believe Judge Carlson properly sustained the objection to this question on grounds of relevance. Second, Wamser attempted to ask Officer Campbell the following question: “[W]ould you agree with the statement from Dutton’s Navigation and Piloting, 13th Edition, published by the United States Coast Guard that says, ‘Position accuracy degrades with increasing distance from transmitting stations as a result of variation and propagation conditions, losses of the signal path and internal receiver conditions’?” This question called for Officer Campbell’s opinion as to the accuracy of a passage in a textbook outlining general circumstances under which the accuracy of Loran C readings might be impaired. The state’s objection to this question was properly sustained because the question dealt exclusively with hypothetical sources of error and did not attempt to relate them to the Loran C reading in Wamser’s case. Had Wamser’s counsel attempted to deal specifically with the possible sources of error in the present case, we believe that he should have been permitted to do so, either by cross-examination or by presentation of independent, expert testimony. However, Wamser’s counsel made no effort to establish the existence of specific factors that might have impaired the Loran C reading in this case. The record gives us no reason to believe that Judge Carlson would have prevented Wamser from exploring potential sources of error actually existing in his case. Our decision with respect to Judge Carlson’s rulings on these two questions is unrelated to any failure by Wamser to make an offer of proof. To the extent Wamser’s cross-examination concerning Loran C was restricted, it was because he failed to ask proper questions, not because he neglected to make an offer of proof. We therefore express no view as to whether a full offer of proof should generally be required on cross-examination.