Solo Communications

Dynamic Mapping

Until now, navigation systems have relied exclusively upon existing maps and coordinate systems. However, we feel that navigation should not be limited to lands that have already been explored. RMAPS® takes navigation to the next level by dynamically generating reusable maps based on a custom relative coordinate system when existing maps and coordinate systems simply do not exist.

Establishing a Relative Coordinate System (READ MORE...)

An accurate coordinate system is an essential foundation behind any map and the first step towards successful navigation. When an existing coordinate system is not accessible or does not exist, RMAPS® can create a coordinate system relative to the location of the lander. This can be envisioned as a 3-dimensional space with the lander located at the origin. The astronaut will then establish the orientation of the coordinate system by deploying the first BreadCrumb® within sight of the lander. The straight line formed between the lander and the first BreadCrumb® will become the positive x-axis of the new coordinate system. The positive y-axis will be the line passing through the lander that is rotated 90 degrees counter-clockwise from the positive x-axis. The positive z-axis is orthogonal to the x-y plane and directed vertically out of the ground.
Map Creation (READ MORE...)

As each BreadCrumb® is deployed, its coordinates will be calculated and transmitted back to the lander by the transceiver on the astronaut's equipment. Once the lander has received the coordinates, they will be plotted on a dynamically generated map for navigational and/or referencing purposes.
Map Reusability (READ MORE...)

When a mission is completed, the created maps are retained in an archive. This allows the specific locations of various points of interest to be retained for future reference. These maps can also be reused on subsequent missions even when the location of lander has changed. This is accomplished by sending the initial map through a conversion process that takes advantage of the concepts behind the relative coordinate system. Before this process can take place, a new relative coordinate system must be initialized. Once this occurs, RMAPS® will establish communication with BreadCrumb® devices from previous missions. The system will then attempt to locate the coordinates of these previously used devices. If the coordinates from two BreadCrumb® devices are discovered, the offset and orientation of the previous map with respect to the current map can be determined. Finally, the coordinates of each BreadCrumb® in the previous map can be updated with respect to the current map.
Tips on Dynamic Mapping (READ MORE...)

In order to achieve the highest accuracy, the z-axis must be calibrated by placing the first BreadCrumb® at an altitude as similar to that of the lander as possible. It is also important that the astronaut deploy each BreadCrumb® as close to their current position as possible since it's coordinates will be determined by the astronaut's distance from other BreadCrumb® devices and perhaps the lander if necessary.

Location Detection

Position tracking is the most crucial element in any navigational system. After all, if you don't know where you are, you'll never reach your destination. RMAPS® uses its own library of customized navigational maps to simultaneously track multiple astronauts in the field. RMAPS® also provides superior location detection accuracy while maintaining impressive flexibility in signal networking. Now you can have confidence that you'll even have signal in the most rugged terrain of the harshest environment in non line-of-sight conditions.

Background (READ MORE...)

Astronauts in the field will have the ability to communicate with BreadCrumb® devices as well as the lander. The astronaut's equipment will calculate the distance to each BreadCrumb® by transmitting a short pulse and performing a round trip transit time calculation on the returned signal. The wake up time for the BreadCrumb® is subtracted from the transit time in order to provide a more accurate measurement. The calculated distances will be used to determine the astronaut's precise coordinates which will then be transmitted back to the lander by the astronaut's equipment.
Algorithm (READ MORE...)

The RMAPS® trilateration location detection algorithm is very similar to the algorithm used in the United State's Global Positioning System (GPS). However, RMAPS® only requires three signals from sufficiently different directions to accurately calculate a 3-dimensional position while GPS requires four. The fourth signal in GPS is needed to solve for the clock error of the receiver due to the lack of clock synchronization between the receiver and transmitting satellite. This clock error does not apply to RMAPS® since distance is calculated based on the round trip transit time of the signal as measured by a single clock. As a result, only three signals are necessary to calculate a 3-dimensional position. In the case of location ambiguity, signal strength will be used as a second means of calculation to determine which ambiguous position is the most likely solution. If more than three signals are detected, RMAPS® will use signal strength and signal direction as calculated from the coordinates of each BreadCrumb® to determine which three signals will produce the highest probable accuracy. The distances and coordinates corresponding to these three signals can then be used to calculate the precise location of the astronaut by solving the following set of three equations:
Sources of Error (READ MORE...)

Multipath and receiver noise are most likely the highest sources of error. However, user error can also be a large factor if the astronaut does not adhere to the suggested practices. An example of this is if the user fails to calibrate the altitude properly by placing the first BreadCrumb® at roughly the same altitude as the lander. The straighter the path of BreadCrumb® devices, the less precise the calculations will be. Assuming that the astronaut uses the suggested procedures, accuracy is projected to be under 50m based on some assumptions of multipath error and a reflection coefficient of about 3.0.
Tips on Location Detection (READ MORE...)

The best possible location accuracy will occur when the astronaut is in the center of three BreadCrumb® devices that form an isosceles triangle. While this is not necessarily the most likely situation to encounter in the field, keeping this principle in mind can improve location accuracy. The more directionally diverse and equidistant the signals are, the more accurate the calculation will be.

Using a reasonable number of BreadCrumb® devices will optimize system performance and network density. It is important to use enough to guarantee that there is always a minimum of three BreadCrumb® devices in range so that the astronaut location's is never lost. However, overuse of BreadCrumb devices will blanket the network with transmissions which could adversely affect system performance. While this will not likely result in loss of signal, it will lead to poor network density and spatial reuse.

RMAPS

Radiolocation Mapping and Positioning System

Dynamic Mapping

Establishing a Relative Coordinate System (READ MORE...)

Map Creation (READ MORE...)

Map Reusability (READ MORE...)

Tips on Dynamic Mapping (READ MORE...)

Location Detection

Background (READ MORE...)

Algorithm (READ MORE...)

Sources of Error (READ MORE...)

Tips on Location Detection (READ MORE...)

What is RMAPS?

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