US Government as Represented by the Secretary of the Army

Honeybee Robotics, Ltd.

Jerome B Johnson

Philip Chu

Jonathan Alfred Holmgren

Kris Zacny

Martin Schneebeli

Garry L Schaefer

A dual aerial-drop penetrometer system includes a high-velocity (&#x3e;30 m/s) penetrometer aerial unit combined with a low-velocity (&#x3c;10 m/s) penetrometer aerial unit. The primary penetrometer is formed as an outer shell having the secondary penetrometer received in telescoping fashion within, which is ejected by a spring ejection mechanism upon impact of the outer shell. Both penetrometers provide deceleration information as they penetrate the soil of interest. The data from the two penetrometers, after analysis, can be used to assess soil strength as well as trafficability for the deployment of remotely-controlled vehicles, for example.

Impact penetrometer systems for characterizing soil properties

An electronic detector configuration enables the accurate determination of pressure differences in scenarios in which conventional detectors and detector systems introduce inherent thermal inequalities at the interface with their immediate environs. A preferred embodiment of the present invention accurately measures snow water equivalent (SWE) while eliminating the need for fluid-filled pillows that contain environmentally hazardous fluids. By matching the thermal conductivity of)surrounding soil to a detector configuration having an inherently low specific heat, it minimizes effects of differences in thermal conductivity at the snow/soil interface that cause SWE pressure sensor measurement errors. Further, it minimizes thermal effects by keeping soil moisture under the configuration approximately the same as that of surrounding soil. The system is environmentally friendly, has a small footprint, and is inexpensive to implement in arrays coupled to communicators suitable for any number of monitoring and warning functions such as snow avalanche and landslide early warning.

Detector and system for indicating pressure change and methods of use

The snow penetrometer apparatus with data acquisition hardware measure force required to push a small dimension tip member into a snow surface at constant speed that: i) is less than 5 mm in diameter or cross-sectional width, ii) has up to a 90.degree. included angle; iii) has a flared tip and iv) is extended beyond a penetrating head. The penetrometer tip member has a high elastic modulus and is attached through a connecting rod to a stiff penetrating head that is in turn attached to a driving rod. The penetrometer tip member acts through a force sensing transducer. The driving rods are a meter in sectional length that can be joined together for snow penetration up to several meters. The depth of snow penetration is determined by measuring movement of a drive motor or drive rods. The penetrometer tip member is driven downward by a constant speed rotary or linear motor. Two different penetrating head designs are used. The first penetrating head design has a diameter slightly larger than the driving rod to reduce sidewall friction. The second penetrating head design has the same diameter as the driving rod to reduce the volume of influence ahead of the penetrating head. Both heads are low included angle of 30.degree. or less. A measured event of the penetrometer tip encountered force is recorded and correlated with depth of penetration for later analysis to determine its mean value and variation about this mean value to obtain an index measure of inter-grain bonding and snow grain size.

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Fairbanks, AK, United States of America

Jerome B Johnson