Editing Upholder/Victoria-class submarine (section)

===Sensors and countermeasures===
As built, the ''Upholder'' class was equipped with the Kelvin Hughes Type 1007 I-band radar for navigational purposes. The submarines were fitted with the Type 2040 Thompson Sintra ARGONAUTE hull mounted sonar, installed in the bow and Type 2026 GEC Avionics passive towed array. The submarines had the Type 2019 Thompson Sintra PARIS passive sonar for active and intercept purposes. They also had the Type 2041 passive ranging sonar and the Type 2004 expendable bathythermograph. The class was fitted with Type 2008 underwater telephone.<ref name=perkins196/> The Type 2040 sonar was intended to be upgraded to Type 2075; however, that upgrade was cancelled in 1991.<ref name=gardiner532/><ref name=saunders88/>

These systems were later upgraded with the installation of the BAE Type 2007 array and the Type 2046 towed array.<ref name=gardiner532/><ref name=saunders88/> The Canadian Towed Array Sonar (CANTASS) has been integrated into the towed sonar suite.<ref name=saunders88/>

The ''Upholder''-class submarines were equipped with the CK035 electro-optical search periscope and the CH085 optronic attack periscope, originally supplied by Pilkington Optronics.<ref name=saunders88/><ref name=perkins196/> After the Canadian refit, the submarines were equipped with Canadian communication equipment and [[Electronic warfare support measures|electronic support measures]] (ESM). This included two SSE decoy launchers and the AR 900 ESM.<ref name=saunders88/>