PORPASS will provide users with a web-application designed to facilitate custom processing and simulations of planetary radar data. The overarching goal of PORPASS is to enhance mission legacy by providing custom processing and simulation of planetary radar datasets beyond the life of any particular orbiting planetary science mission, ensuring data and code longevity and relevance as well as opening the door to the next generation of researchers.
Instruments
For this initial development, we focus our efforts on radar sounding data from SHARAD, MARSIS, and LRS.
MRO SHARAD
The Mars Reconnaissance Orbiter (MRO) Shallow Radar (SHARAD) has been collecting information on the surface and subsurface of Mars since late 2006. SHARAD emits a 10-watt chirped pulse downswept from 25 to 15 MHz, yielding a 15-meter range resolution in free-space.
MEx MARSIS
The Mars Advanced Radar for Ionosphere and Subsurface Sounding (MARSIS) onboard the European Space Agency's (ESA) Mars Express (MEx) spacecraft has been observing Mars since 2005. MARSIS operates in various modes, and the 1-MHz bands centered at 3, 4, and 5 MHz are used for subsurface sounding.
SELENE LRS
The Selenological and Engineering Explore's (SELENE, AKA Kaguya) Lunar Radar Sounder (LRS) is a frequency-modulated / continuous-wave radar sounder with a 2-MHz bandwidth centered at 5 MHz. LRS was in operation from 2007–2009.
Applications Under Development
PORPASS will feature two main software applications as well as a GIS environment.
GRaSP
The Generalized Radar Sounder Processor (GRaSP) is the heart of PORPASS. Most modern sounder systems rely on synthetic-aperture radar (SAR) processing to enhance along-track resolution and boost the effective signal-to-noise ratio. Despite the various differences in operations, all radar sounders operate under the same physics regime, therefore allowing one to design a generic processor for any radar sounder system once the various differences between radar instruments have been accounted for.
OaRS
The Orbital Radar Simulator (OaRS) is an attempt to answer a long-standing issue in planetary radar sounder science: the lack of any publicly-available, open-source full-waveform radar simulator. Under development by members of the Center of Wave Phenomena at the Colorado School of Mines, OaRS will provide end-users with the ability to simulate radar data from various instruments through free-form subsurface environments.
PORPASS GIS
To accompany the processing and simulation capabilities of PORPASS, we will develop an interactive geographic information system (GIS) that will display radar ground-tracks over various basemaps. The GIS will allow users to select radar observations over regions-of-interest and select bulk processing parameters. Both Mars and Earth's Moon will be accessible as basemaps.
The PORPASS Team
The PORPASS Project is managed by Matthew R. Perry (PSI) on behalf of Principal Investigator (PI) Nathaniel Putzig (PSI). Other Investigators involved in the development of PORPASS include Megan B. Russell (PSI), Gareth Morgan (PSI), Frederick Foss (Freestyle Analytical and Quantitative Services, LLC), Paul Sava (Colorado School of Mines), Dylan Hickson (Colorado School of Mines), Bruce Campbell (Smithsonian Institution), and Andrew Kopf (US Naval Observatory).
Launch Date
PORPASS is expected to launch in May 2026.