PureSpectral is developing a receive-only passive radar for low-altitude drone detection. It uses signals that existing cellular networks already transmit — no dedicated transmitter, no new spectrum. Built in Finland for European critical infrastructure and defence.
Recurring drone and airspace incidents have increased the focus on layered low-altitude surveillance across Northern and Eastern Europe. Each existing sensor type covers part of the problem; wide-area, persistent coverage at low altitude remains costly to scale.
Emits a signal of its own; costly to scale densely at low altitude.
Relies on the drone's own transmissions — blind to RF-silent and autonomous platforms.
Line-of-sight, weather- and range-limited; deployed site by site.
PureSpectral uses existing cellular downlink signals to create a passive sensing layer for low-altitude airspace. The sensor adds no dedicated RF transmission and requires no additional spectrum licence. Initial operational focus: low-altitude operations, approximately 30–500 m above ground. The same node is designed to also use broadcast signals (FM, DVB-T, DAB) as a backup illuminator.
A receive-only sensor reduces its own emission signature and removes reliance on a dedicated radar transmitter.
Coverage potential increases with the density and diversity of suitable cellular illuminators and sensor sites.
European control of core IP and supply-chain resilience are design priorities — aimed at reducing exposure to non-EU export restrictions.
A passive receiver with its own antenna and processing, intended for deployment at or near existing cellular sites.
Designed to reduce site-specific integration and calibration work, so that the same node can be deployed across heterogeneous sites.
Designed for independence from any specific base-station vendor or network generation. Current proof-of-concept work focuses on commercial LTE downlink signals.
Operators and site owners already have the sites, power and backhaul. PureSpectral is exploring infrastructure-access partnerships in which a passive receiver is hosted at selected sites. Commercial models — including hosting arrangements or shared revenue from sensing services — are part of ongoing partner discovery.
Receive-only. No changes to the network, no service impact, no new licensing.
Site suitability and commercial accessibility are the focus of current discovery.
Deployment and hosting models are developed together with the first infrastructure partners.
PureSpectral is intended as a feeder sensor in a layered architecture: an additional, receive-only detection layer for low-altitude airspace. It does not replace active radar or effectors.
The sensor adds no dedicated RF transmission.
Designed to detect targets regardless of whether they emit RF — complementing RF-detection systems.
Integration into existing C-UAS and command-and-control systems through standard interfaces is a design goal.
PureSpectral is an early-stage Finnish dual-use company developing passive radar for low-altitude drone detection. The founder is available for interviews on passive sensing and European low-altitude airspace security.
We are in early conversations with operators, site owners, defence and critical-infrastructure stakeholders about evaluation and design-partner cooperation.
PureSpectral was founded by Akseli Kaaro, an RF and telecom engineer with 25+ years in cellular product development across seven countries — most recently as product development leader in 5G base-station development. B.Sc. Electronics & Telecommunications, M.Eng. Technology Competence Management, MBA (2025). Named inventor on the Finnish patent application. Private pilot (PPL(A)).
PureSpectral Oy, Helsinki, Finland. Engineering and signal-processing hires open with the pre-seed round; advisory board planned.
For operator, defence and critical-infrastructure conversations.
Open the contact form → Investor / Grant Pre-seed round.Deck and a founder call on request.
Request investor access → Press / Media Interviews.Founder interviews on request.
See the press door →